Organelles In Animal Cells Essay

Organelles In Animal Cells Essay
Organelles are the internal structures of the cell that are important for the cell to survive. Each
organelle has a specific function for the cell. The types of organelles in the cell can be different from
each other depending on the type of cell. Plant cells and animal cells both have a cytoskeleton,
endoplasmic reticulum (smooth and rough), golgi apparatus, mitochondrion, nucleus, plasma
membrane, and ribosomes. Animal and plant cells also have vacuoles, but they are rarely found in
animal cells. Vacuoles in animal cells are very small compared to the vacuoles in plant cells.
Lysosomes are also rarely found in plant cells but mostly found in animal cells. The cytoplasm is a
semifluid in the plasma membrane. It is in all eukaryotic cells. In prokaryotes, this is where the
chemical processes of the cell take place. In eukaryotic cells, this is where organelles perform their
functions. Cellular respiration also takes place here. One of stages of cellular respiration is
glycolysis. Glycolysis is when glucose breaks down to form two pyruvates and 4 ATP. Its net result
of 2 ATP is important for another process called the Krebs Cycle. This process is important because
it begins cellular respiration. The cytoplasm also gives the cell its shape; without it, the cell would
be "deflated" and substances would not be able to move throughout the cell. Organelles would have
difficulty functioning too. It has been misunderstood that organelles float freely in the cytoplasm
even
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The Network Of Polymeric Structure
The cytoskeleton, network of polymeric structure is a highly dynamic framework comprised of
microtubules polymerized from α– and β–tubulin subunits and microfilaments (AFs) polymerized
from G–actin and related proteins. Numerous studies have shown the presence of cross–bridges
between cortical microtubules and the PM, so they maintain a link and this linkage can extend to the
cell wall (Akashi et al., 1990; Akashi and Shibaoka, 1991; Shibaoka, 1994; Sonobe and Takahashi,
1994). Plant cytoskeleton maintains proximity with the plasma membrane that provides an
important platform for signal perception and transduction (Gilroy and Trewavas, 2001; Wasteneys
and Galway, 2003). Above described proximity concept suggests this framework as a downstream
targets of various signalling pathways. The bond arises between plasma membrane and cytoskeleton
through a hydrophobic domain which present on the tubulin molecule or indirectly through
interaction with an integral membrane protein (Sonesson et al., 1997). Phospholipase D (PLD) is a
plasma membrane protein which has been characterized and confirmed for having the ability to
make connection between cortical microtubules and the plasma membrane (Gardiner et al., 2001;
Dhonukshe et al., 2003; Drobak et al., 2004; Hong et al., 2008). Therefore PLD has been suggested
to function as a structural and signalling link between the plasma membrane and the cytoskeleton in
Arabidopsis in tobacco (Gardiner et al., 2003). Cytoskeletal reorganization

Protein Phosphatase Receptor Analysis
Its function is regulated by dopaminergic and glutaminergic receptors. When stimulated by
dopaminergic receptors it is a potent inhibitor of PP1α (Hemmings, 1984). In contrast, when
stimulated by glutaminergic receptors, the inhibitory activity of DARPP–32 against PP1 is reduced
(Halpain, 1990). DARPP–32 is regulated by brain–derived neurotropic factor as well as the Akt
pathway and CDK5/p35 pathway (Stroppolo, 2001) (Bogush, 2007).
Protein Phosphatase Inhibitor 2 Protein Phosphatase Inhibitor 2 (I–2) I–2 is a heat stable protein that
can inhibit the catalytic subunits of PP1 (Huang, 1976). When unphosphorylated I–2 is inhibitory to
PP1c however, phosphorylation of I–2 can induce PP1c activity (Cohen 2002). It has been shown to
be important in cell cycle regulation and is found at the centrosomes during interphase (Eto, 2002).
The consensus as to the purpose of I–2 is to act as a regulator of PP1 to control the kinase/PP1
balance and activate different cellular events. It has also been shown to play a role in tubulin
acetylation in the cilium of retinal epithelial cells. Wang and Brautigan showed that I–2 localizes to
the cilium of human retinal epithelial cells with PP1. RNAi knockdown of I–2 showed ... Show
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In order to answer the question from the introduction "How do such a small number of phosphatases
regulate the phosphorylation of thousands of proteins while also allowing each protein to be
regulated independently?" PP1 has evolved mechanisms to bind numerous different subunits in
order to function the way it needs. There are many more regulatory subunits than discussed above.
The subunits discussed above are the major subunits involved in PP1 dynamics. It is a near certainty
that more regulatory subunits will be discovered. If PP1 could only form a complex with one
subunit at a time there are ~42 different holoenzyme structures possible with the subunits discussed

Cell And Molecular Biology Lab Report Essay
Carijo Taro
Cell and Molecular Biology Lab
September 30, 2015
Cell Motility Lab Report
Introduction:
Cell movement involves both the interactions between signaling molecules and the structure of the
cytoskeleton (Holmes et al., 2012). Tiny hair like structures referred to as cilia are located on the
surface of eukaryotic cells. Cilia are most responsible for the movement of cells and can process
external signals which coordinate the correct arrangement of the inner organs during the
development of an organism. Approximately 600 different cilia proteins are synthesized inside a cell
and then transported into cilium. Disruption of this transport referred to as intraflagellar transport
can result in errors during the assembly of cilia (Planck, 2013). In order to fully understand cell
motility one needs to know that cell movement deals with several types of motion, these include the
movement of an entire cell through fluid or a macrophage crawling through tissues and engulfing
foreign bacteria. Also, beating of cilia or flagella causes the movement of fluid past cells which are
anchored to a solid surface (Mitchell, 2015). Even though eukaryotic cells can move in a variety of
ways, the main component of motility includes protein filaments called the cytoskeleton. The
cytoskeleton is composed of three types of filaments which include; microfilaments, microtubules,
and intermediate filaments (Alberts et al., 2014). Although there are three types of filaments, this lab
focuses

Mechanotransduction, which is the process by which cells...
Mechanotransduction, which is the process by which cells converts mechanical stimuli to
biochemical signaling cascades, is involved in the homeostasis of numerous tissues. The
mechanotransduction of oscillatory shear stress by bone resident cells has gained special attention
because of its role in regulating bone formation, remodeling and disease. Mechanical forces,
especially, fluid shear stress has been observed to induce several cellular responses in osteoblastic
cells, including intracellular calcium influx, stress fiber formation, ATP, nitric oxide and
prostaglandin E2 release, MAPK activation and gene expression changes 1–5. In particular, there is
intense interest in identifying the primary molecular mechanism of the osteoblast ... Show more
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Even cells that have been shown to sense mechanical forces (e.g, apical fluid shear) through changes
in the specific activities as a result of stress–induced deformation at the apical surface, respond
differently to the same mechanical stimulus depending on the deformation at the basal surface (106).
Thus the physiologic response of the cell to any mechanical stress is governed by the physical state
of the whole cell, and not by changes in any single signaling molecules. This cellular mechano–
sensing and corresponding responsiveness of a cell firstly governed by the stress imposed on it
specifically at the surface. In most of the mechanotransduction studies, the descriptions of the
imposed force amplitude are grossly mentioned (like...). But the force variations include magnitudal
and vectorial changes at sub–cellular surface due to heterogeneous surface physical/rheological
properties (surface topology, fluidity and stiffness), which actually govern the spatial activation of
the biochemical signal are overlooked. In fact, the determination of spatial surface stress map is very
necessary for interpreting any type of cellular response that made by mechanical force. Thus, before
analysis of the mechanotransduction, in this chapter, we first computationally determined the cell
surface shear stress map using the cell surface topology information obtained by AFM. This stress
map further can explain the related spatial cellular activity as cellular deformation more

Microtubule Stabilizing Drugs Research Paper
Microtubule Stabilizing Drugs and the Effects on Cancer Cells
By: Amber Erickson
Introduction
Microtubule Structure and Dynamics Microtubules are structures that are existing in all eukaryotic
cells and are a part of the cytoskeleton, and are important components of many cellular functions
such as structural support, cell motility, intracellular transport of vesicles and organelles, and
cellular division. Microtubules are composed of α (–) and β (+) tubulin heterodimers that are
arranged in a polar longitudinal rows called protofilaments, and then further organized into a
circular 13 protofilament arrangement (Valiron et al, 2001).
Microtubules are assembled at the microtubule organizing center (MTOC), which consist of
centrosomes surrounded by pericentriolar material (PCM) in animal cells. Nucleation, which is the
initiation of microtubules, occurs at the MTOC and consists of 13 gamma–tubulin subunits forming
an open ring where the first set of tubulin are added at the positive end (Tassins and Bornens, 1999).
Growth of the microtubule consists of the polymerization, addition of tubulin dimers on the positive
end near the cell periphery, faster than tubulin dimers can be lost at the minus end, which is attached
to the centrosome toward the cell center. ... Show more content on Helpwriting.net ...
The specific binding site on the tubulin and on the microtubule differ amongst the microtubule
targeting drugs. Other aspects of how microtubule targeting drugs can be varied include the
sensitivity to tubulin isotype, different tissues and tumors susceptibility, different forms of resistance
, different mechanisms for suppression of microtubule, and different degrees of variability
(Mooberry, 2011). These different factors all contribute to how a specific microtubule targeting drug
will act when used in treatment of cancer and the success or failures it will

Eukaryotic Cell Lab Report
With the use of a light microscope and an electron microscope, scientists discovered that organelles
in a eukaryotic cell do not actually float around freely. They discovered the cytoskeleton, which is
key towards a cell's structure and activity. (112) It is extremely dynamic and important for the cells,
as provides a secure hold on many organelles and cytosolic enzyme molecules. In addition, it can
bend the plasma membrane inward to form either food or other phagocytic vesicles. It is also
involved with cell motility with its interaction with motor proteins. This correlates towards
movements and changes in a cell's location. This is the result of the cytoskeleton working with
motor proteins by using it as "feet" to walk to a different location. It is a network of fibers that is
composed of microtubules, microfilaments, and intermediate filaments. (113) Out of the fibers it is
composed of, microtubules are the thickest, microfilaments are the thinnest and intermediate
filaments are diameters in a middle range. Microfilaments maintains cell shape, changes in shape,
muscle contraction, cytoplasmic streaming, cell motility and division for animal cells. (113)
Microfilaments are made through a twisted double chain ... Show more content on Helpwriting.net
...
Within the plasma membrane, they form a 3D network to support the cell's shape. (Chapter 6 slide)
Therefore, it helps support the cell shape with this network by keeping the organelles in place and
then assists in its movement. In addition, its direct role is to bear tension via pulling forces. This
whole network gives the cortex (outer cytoplasmic layer) a semisolid form rather than a fluidity
structure. In addition, in some animal cells the microfilament make up the core of microvilli that
increase a cell's surface area. (117) Therefore, this filament is essential towards maintenance of cell
shapes as it helps support it and, in some cases, make up the surface

4. 2 Intracellular Binding Partners Of Podocalyxin Lab Study
1.4.2 Intracellular binding partners of podocalyxin
Two types of protein have been repeatedly shown to directly interact with the cytoplasmic domain
of PODXL, the NHERF isoforms 1 and 2 (solute carrier family 9 (Na+/H+ exchanger) member 3
regulator –1 and –2) and ezrin, a member of the ERM family (see Figure 4 (Li et al., 2002; Orlando
et al., 2001; Schmieder et al., 2004; Tan et al., 2006)). The DTHL signaling motif in the cytoplasmic
tail of PODXL is required for its interaction with the NHERF1/2 proteins via their PDZ domains (Li
et al., 2002; Tan et al., 2006). These two adaptor proteins form complexes with many different
proteins and are implicated in protein trafficking, ion transport and signaling (Donowitz et al., 2005;
Weinman, ... Show more content on Helpwriting.net ...
1.5 Ezrin – a member of the ERM family
The ERM family of proteins, consisting of ezrin, radixin and moesin form a conserved branch of the
FERM (four–point–one, ezrin, radixin, moesin) superfamily of proteins (Bretscher et al., 2002).
These proteins are closely related and best known to act as linkers between integral membrane
proteins and the and the cortical cytoskeleton, i.e. the cytoskeleton underlying the plasma
membrane, and are thus key regulators of cell morphology and polarity (Fehon et al., 2010). In fact
their amino acid sequences are strikingly similar (at least 70%), though there are certain differences
in phosphorylation sites between these proteins. For example, ezrin can be phosphorylated on
tyrosine residues that are not found in radixin or moesin (Krieg and Hunter, 1992). In addition,
ERMs show some tissue–specific expression and are reported to have many overlapping functions
and therefore a certain level of functional redundancy (Fehon et al., 2010). Ezrin is most abundantly
expressed by epithelial cells, moesin by endothelial cells and radixin by hepatocytes.
ERMs structure is characterized by a plasma membrane–associated FERM domain of approx. 300
amino acids in the N–terminus, followed by a long region with a high α–helical propensity and

Functions Of Eukaryotic Cells For Various Functions And...
Microtubules are an essential part of eukaryotic cells for various functions and processes, and are
located throughout the cytoplasm in the cytoskeleton. Microtubules are essential for multiple
cellular processes such as, cellular division and cellular movement and transport(6). Since
microtubules are required for many cellular processes, mutations involving microtubules can cause
various diseases including neurodegenerative diseases and cancer(5). One of the most common
neurodegenerative diseases involving mutations of microtubules is Alzheimer's Disease. Alzheimer's
causes the neuron cells in the brain lose function and eventually die causing the brain to
deteriorate(1). Microtubules affect this disease by their associated proteins, ... Show more content on
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One of the types of tubulin is acetylated tubulin, and are located on stable microtubules. The
stability of an acetylated protein allows the protein to become a marker for macromolecule and
organelle transportation in neurons(2). It was hypothesized that the zebrafish brain would have a
higher concentration of acetylated tubulin than in the zebrafish eye.
Methods
Protein Extraction Tubes containing zebrafish brain or eye tissue and 500μl of extraction buffer
were obtained and tissue was grinded to a slurry and homogenized. The homogenate was placed in a
100C hot block for 1 minute. The sample was vortexed for 5 minutes and spun at 14,000 RPM for a
total of 30 minutes. The 200μl of supernatant was removed and put into a tube and stored at –80C
for a week. The rest of the supernatant was also placed in a separate tube and labeled as S1. The
supernatant was resuspended in 500μl of the previously used extraction buffer and vortexed. A large
amount of the solution was removed and put into a tube labeled P1 and was also kept at –80C for 1
week.
Protein Quantification by the Bradford Assay The S1 and P1 samples underwent serial dilutions to
create a total of 3 tubes per sample. Fifteen cuvettes were gathered and 30μl of each sample was
added to the cuvettes. The first cuvette was filled with 1.5 mL of Coomaisse Reagent. Coomaise
reagent was added to each cuvette, with one minute intervals between each measurement to allow
the protein mixed with

Statistical Analysis On The Rate Of Cytoplasmic Streaming
Statistical analysis of variations in the rate of cytoplasmic streaming in Nitella pseudoflabellata due
to differences in cell width and treatment with mechanism–inhibitory cytochalasins C and D
observed using light microscopy
Introduction
Cytoplasmic streaming is the organised flow of the cytoplasm and its constituents within a living
cell (Shimmen et al., 2004). Organelles and important molecules move through the cytosol along the
structure of the cytoskeleton (actin filaments and microtubules) with the aid of myosin I, an actin–
binding motor protein that plays a part in various cell functions including cell motility and
endocytosis (Flavell et al., 2008). Actin microfilaments (F–actin) are the thinnest filaments of the
cytoskeleton, ... Show more content on Helpwriting.net ...
As suggested by Seagull et al. (1980), while the rate of cytoplasmic streaming does not vary with
the size of the motile particle (organelle, cargo molecule, etc.) or the size of the cell itself, larger
cells with increased surface area may absorb these mechanism–inhibitory substances more readily
and may therefore have slower rates of cytoplasmic streaming as less F–actin is available to the
myosin complex at any one time.
Cytochalasins are a group of small organic fungal metabolites which are capable of permeating cell
membranes
Nitella pseudoflabellata is
Aims
1. To measure the rate of cytoplasmic streaming in Nitella pseudoflabellata cells in pond water
2. Correlate the rate of cytoplasmic streaming with the width of the cell
3. Determine the mechanism behind cytoplasmic streaming in Nitella pseudoflabellata by observing
variations in cytoplasmic streaming following treatment with cytochalasins C or D
Materials and Methods
Materials and methods were followed from (Keszei, 2014) with a few exceptions: o Only 50 µL of
each cytochalasin C and cytochalasin D were provided o Cytoplasmic streaming was measured 4
times after flushing the cells with pond water, at 5 minute intervals
Results
Table 1 – Rate of cytoplasmic streaming in Nitella cells in pond water
Cell # Cell width (μm) Time to

Factors That Affect The Growth Of Cells And Their Cellular...
Significance
Age is a universal time–dependent deterioration factor that affects all organisms and their cellular
functions, thus, determining their lifespan. Actin organization and function declines with age in
many cells, tissues and organs. For example, age–associated declines in myosin and actomyosin
ATPase activities, changes in myosin structural state, and oxidative damage to actomyosin occur and
may contribute to sarcopenia [1]. Similarly, the age–associated deficit in the motility of fibroblasts,
which contributes to impaired wound healing, has been linked to a progressive decline in actin
organization [2]. There is an age–associated decline in immunological synapse formation between
CD4+ T cells and the antigen presenting cells (APC) in which actin cytoskeletal structure and
dynamics are critical for this formation and activation of T cells (6 and 14 – CS). Defects in T cell
activation are shown to be a result of defects in recruiting actin binding protein talin, which is
critical for reorganization of the actin cytoskeleton, and development of lamellipodia, which is
responsible for increasing the communication surface area between CD4+ T cell and APC at the
immunological synapses (6 and 14 – CS). Finally, actin cytoskeleton integrity declines in
Alzheimer's patients affecting the integrity of dendritic spines by disrupting its morphology and
impinging memory and learning (20n21 – CS). In Alzheimer's patients there is a disproportionate
expression of cofilin,

Myosin And Myosin Function And Its Effect On A Huge Number...
Abstract:
The actin–myosin interaction is most commonly known for its role in sliding filament theory, where
myosin II bundles interact with actin filaments to shorten muscle sarcomeres and ultimately contract
the muscle. However the myosin superfamily is huge, numbering 17 different proteins to date, and
encompassing many different roles. The interaction of myosin and actin in non–muscle cells is thus
a huge topic, but in understanding the structure, function and regulation of this part of the
cytoskeleton, it is possible to find new drug targets and design new treatments to a huge number of
diseases. One such target is the Rho–associated protein kinases (ROCKs), which are responsible for
the regulation of the actin myosin cytoskeleton. This report aims to briefly cover the basic role of
the actin–myosin cytoskeleton in non–muscle cells, how it is regulated by the ROCK family of
serine/threonine kinases, and how ROCK inhibitors have could have huge therapeutic potential.
Introduction:
The cell cytoskeleton in an immensely complex system of protein filaments and motors, which is
responsible for maintaining the rigidity and architecture of the eukaryotic cell, while transporting
vesicles and organelles throughout the cell and assisting in cell movement. There are 3 types of
protein filaments in the cytoskeleton – actin filaments, intermediate filaments, and microtubules –
and 3 associated motor proteins – myosin, dynein, and kinesin. Of particular interest, and the focus
of

Advantages And Disadvantages Of Prokaryotes
All living organisms on Earth are classified within three domains – Archaea, Bacteria, and Eukarya.
Bacteria and Archaea encompass a generalised classification known as the prokaryotes. This
definition follows the extensive similarities between the two domains, such as their manner of gene
expression, their fundamental metabolic pathways, as well as their lack of membrane bound
organelles, and compartmentalisation. Due to the cellular compartmentalisation that eukaryotes
exhibit, as well as more complex modes of metabolism and replication, prokaryotes are generally
considered to be the precursors to eukaryotic cells. One of the other defining characteristics of
eukaryotic cells that allow for multicellularity to occur is the presence of a complex ... Show more
It is therefore suggested that MreB and actin originated from a common ancestor, as so, further
suggests that actin was a result of MreB divergence in eukaryotes. Bacterial MreB functions in
maintaining the shape of the bacterial cell, whereby MreB assembles into filaments which display
an extensive structural resemblance to actin. The divergence of MreB in eukaryotic cells is seen to
be similar to the divergence of FtsZ to tubulin, where MreB acquired new functions as eukaryotes
evolved. These new functions included the ability to perform cell division specific to eukaryotic
cells, cell movement through pseudopodia, and phagocytosis. Phagocytosis is postulated to have
been a central step in the success of eukaryotic evolution, as the ability to engulf other organisms
such as bacteria and archaea led to eukaryotes becoming predators. The ability to perform predation
contributed heavily to the survival of the eukaryotic line, as it reduced competition. Phagocytosis
also allowed for the engulfment of cyanobacteria and other bacteria which contributed to
endosymbiosis, further increasing the complexity of eukaryotic cells. In order to perform
phagocytosis, eukaryotic cells would have had to remove their inflexible cell wall, a remnant of
their prokaryotic ancestors. The remaining plasma membrane would have allowed for increased
flexibility and the ability to project towards the prey,

The Membrane And Its Effects On Human Development
It is generally accepted that resting CaMKIIβ bundles and stabilizes actin cytoskeleton. Transient
activation of CaMKIIβ relaxes cytoskeleton, promotes actin polymerization and CaMKIIβ
recruitment, and favors cytoskeleton growth. This model has been shown in both synaptogenesis
(Okamoto et al., 2007) and OL maturation (Waggener et al., 2013). Based on this theory, we
proposed that prolonged CaMKIIβ activation by NMDA–R–mediated Ca2+ influx leads to
destabilization of actin cytoskeleton and membrane disintegration in mature OLs. Although our
experiments unambiguously showed that NMDA–R activation results in CaMKIIβ activation, direct
proof that links CaMKIIβ activation and membrane reduction are lacking. All the existing CaMKIIβ
inhibitors ... Show more content on Helpwriting.net ...
As mentioned in chapter 5, a repeated measure experiment using OLs from CaMKIIβA303R mice
will be the best way to investigate this question. The CaMKIIβA303R mutant retains its ability to
bundle F–actin, but loses its Ca2+/CaM binding capacity. Based on our proposed model, Tat–
induced [Ca2+]i increase should have no effect on OL membrane area since Ca2+/CaM can not bind
and activate CaMKIIβA303R, and promotes its release from actin cytoskeleton.
Most of our experiments are done in mice cells. Since HIV is a human disease, we used an hBrnAgg
model to try to verify our finding in human cells. We thought that the hBrnAgg model serves our
experiments best because 1) it mimics the in vivo environment with the presence of all major CNS
cell types, 2) myelination has been observed in the model by other investigators, thus fulfill the
needs of studying effect of HIV/Tat on both OLs and myelin, and 3) the hBrnAgg model can be
maintained for a long period of time (up to 60 days), made it a good model to study long–term effect
of HIV/Tat.
Our immunostaining experiments suggested that there are far less OLs in the aggregates than we
expected. Under EM, plenty of synaptic structures, both symmetric and asymmetric, were observed
in the hBrnAgg. However, cells with typical mature OL characteristics, including dark cytoplasm
and nucleus, elongated, thin strands of endoplasmic reticulum; numerous mitochondria, and stacks
of Golgi apparatus, were rarely

Kinesin Family Research Paper
Kinesins: Similar to dyneins, kinesins use microtubules to transport cargo along, and they use the
chemical energy of ATP to drive conformational changes that generate motile force. Based on
observations made using electron microscopy, five major kinesin families were initially discovered
in the mouse brain5, 6. It is now thought that there are 45 mammalian KIF genes, but there could be
twice as many KIF proteins as multiple isoforms can be generated by alternative mRNA splicing7.
KIFs constitute 15 kinesin families, which are termed kinesin 1 to kinesin 14B according to the
results of phylogenetic analyses1, 7, 8 (Fig. 1a). All members of the kinesin superfamily contain a
kinesin motor domain (see the figure; light green). In general, the ... Show more content on
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See also: The Role of the RanGTPase in Mitotic Spindle Assembly
Metaphase is a dynamic situation (Figure 1b–iv), in that chromosomes oscillate around the
metaphase plate, reflecting a dynamic balance of pushing and pulling forces (Helmke et al., 2013).
Moreover, even though metaphase chromosomes are held under tension while they are attached to
both poles, there is a constant poleward flux (treadmilling) of tubulin in the kinetochore MTs. This
indicates that tubulin subunits are constantly added at the kinetochores and lost at the centrosomes.
During anaphase A (when chromosomes move towards the poles; Figure 1b–v), chromosomes are
pulled towards spindle poles by MT shortening at kinetochores (depolymerisation of MT plus ends)
and the poleward flux (depolymerisation at MT minus ends); the relative contribution of these two
forces varies between cell types (Walczak and Heald, 2008). During anaphase B (when poles move
apart; Figure 1b–vi), elongation of polar MTs results from the pushing force generated by kinesin–5
motors located in the zone of MT overlap. In addition, dynein motors located at the cortex
contribute to pole separation by pulling on astral MTs. Both of these latter mechanisms are
reminiscent of those that appear to separate centrosomes at

Factors That Affect The Activity Of Contractile Activity
During prolonged activity, muscles show a decline in ability to respond to stimulation with optimal
levels of contractile activity; this is a phenomena denoted as muscle fatigue (MF) (1). The causes of
MF are not yet understood, however there are many observations of associations between metabolic
and biochemical factors with MF. In order for force to be generated by muscles, calcium ions which
are released from the sarcoplasmic reticulum bind to troponin. The new troponin–Ca2+ complex
cause's tropomyosin to change shape, exposing the binding site on actin. Myosin then binds to actin,
causing cross bridge tilting, and generating contraction (1).
Lactic acid is commonly perceived as a primary cause of MF to due to its intracellular muscle
acidosis effects. Acidosis lowers the sensitivity of the contractile apparatus to calcium ions, because
the H+ ions competes against Ca2+ for binding to certain binding sites on troponin. (2).This leads to
decreased force development. However, low pH has many effects which do not favour development
of MF, such as its ability to help maintain excitability, and decreased rate of fatigue. Overall, there is
little evidence suggesting that the net effect of lactic acid results in MF.
Potassium ions is a metabolite which decreases calcium ion release from the SR. Shifts in levels of
potassium and calcium ions in and around skeletal muscle fibres will alter the membrane potential
of the muscle cell, making it more or less prone to stimulation.

Cytoskeleton Helps Keep the Cells Intact
Similar to how the bone skeletons act as an internal support in our bodies, the cytoskeleton has a
vital role in supporting the cell internally. The cytoskeleton helps keep the shape of the cells intact,
and it is also a network that allows substances to move within the cells. It is essentially the internal
framework of the cell just as the bones are the internal framework of our body. The cytoskeleton
becomes a very important role in our body when the shapes of the cells need to be maintained and
organelles need to move within the cells. Because there are different shapes of cells for different
organs based on their roles, the cytoskeleton provides support by determining and maintaining the
structures and shapes of the proteins through its networks within the cytoplasm. For every
eukaryotic cell, the two important cytoskeletal elements are the microtubules and the
microfilaments. For animals, intermediate filaments are the third element. The microtubules and the
microfilaments allow substances to move within the cells, and the intermediate filaments are
between the microtubules and the microfilaments. Microtubules have diameters of about 25 nm, and
they vary in length but have the potential to grow longer (J.Kimball, 2013). According to Steinmetz
(2007), the microtubules form protofilaments through the bonding between tubulins alpha and beta.
Microtubules are most commonly found in the centrosome during cell division. Another important
aspect of the microtubules is the

Essay on Endosymbiosis
Endosymbiosis
Endosymbiosis is the theory that eukaryotic cells were formed when a prokaryotic cell ingested
some aerobic bacteria. The first step of the evolution of a eukaryotic cell is the infolding of the
cellular membrane. This process takes place when the plasma membrane folds inwards and develops
an envelope around a smaller prokaryotic cell. Once the smaller cell is engulfed, it becomes
dependent upon its host cell. It relies on the host cell for organic molecules and inorganic
compounds. However, the host cell also benefits because it has an increased output of ATP for
cellular activities and becomes more productive. This ATP comes from the mitochondrion (the
aerobe) that is engulfed.
All eukaryotic cells contain the ... Show more content on Helpwriting.net ...
The protein–synthesizing machinery in mitochondria and chloroplasts resemble prokaryotes. This is
shown through their ribosomal RNA and the structure of the ribosomes. The ribosomes are similar
in size and structure to bacterial ribosomes. fMat is always the first amino acid that is in the
mitochondria and chloroplasts transcripts. The antibiotics that act by blocking protein synthesis in
bacteria also block protein synthesis in mitochondria and chloroplasts. These antibiotics do not
interfere with protein synthesis in the cytoplasm of the eukaryotes. The inhibitors that effect the
protein synthesis of eukaryotic ribosomes do not change the protein synthesis of the bacteria,
mitochondria, or chloroplasts.
Mitochondria and chloroplasts have two membranes that surround them. The inner membrane is
probably from the engulfed bacterium and this is supported by that the enzymes and proteins are
most like their counterparts in prokaryotes. The outer membrane is formed from the plasma
membrane or endoplasmic reticulum of the host cell. The electron transport enzymes and the H+
ATPase are only found in the mitochondria and chloroplasts of the eukaryotic cell. (2)
Currently, there are two major competing theories for the endosymbiotic origin of eukaryotic cells.
The first theory claims that the eukaryotic cell is a combination of an archaeon with a

The Membrane Of The Cell Membrane Essay
The cell membrane consists of eight distinctive parts that each have their own unique structure and
function. The phospholipid bilayer is an integral part of the cell membrane because it is the external
layer of the cell membrane and composes the barriers that isolate the internal cell components and
organelles from the extracellular environment. It is composed of a series of phospholipids that have
a hydrophobic region and a hydrophilic region. These regions are composed of the hydrophilic
heads and the hydrophobic tails of the phospholipids, this organization of the polar heads and
nonpolar tails allows the heads of the cell to form hydrogen bonds with water molecules while the
tails are able to avoid water. The phospholipid bilayer also has many important functions within the
cell, it gives the cell shape, provides protection, and it is selectively permeable which allows it to
only let very specific molecules pass through its surface. The phospholipid bilayer is an important
structure because it prevents harmful and unwanted molecules from entering the cell and isolates
organelles which helps to maintain the internal environmental homeostasis of the cell.
Another vital component of the cell membrane are the integral proteins. Integral proteins are
embedded within the phospholipid bilayer, these proteins are typically transmembrane proteins
which means that one end extends to the exterior of the cell while the other connects to the interior.
Integral proteins are

A Study On Cell Adhesion Molecules
Name:
Instructor's Name:
Course:
Date:
Cell Adhesion Molecules
Introduction
Cells are independent units of life. However, when a cell becomes part of an organism, it becomes
part of a tissue and organ system. Cells in a tissue are joined to each other and to the extracellular
matrix (ECM) by cell junctions. There are three kinds of cell junctions: Occluding junctions,
anchoring junctions and communication junctions. Occluding junctions occur in the epithelium
where the adjacent cells are so tightly sealed together that even small molecules cannot pass.
Communicating junctions allow the exchange of chemical and electrical signals between cells.
Anchoring junctions are the ones which attach a cell either to its neighbor or to the extracellular
matrix. Formation of an anchoring junction requires the cells to stick to each other. Various
molecules mediate adhesion between cells following which the cytoskeleton forms a structure
around them. The anchoring junctions thus formed can be of four types– desmosomes,
hemidesmosomes, focal adhesions and adherens junctions. In order for a proper tissue to form, it is
important for the cells of the tissue to bind together. It is equally important to prevent the invasion
and binding of other cells. Thus, cell adhesion has to be specific. This is where the cell adhesion
molecules come into play (Alberts et al. 2002).
Cell Adhesion Molecules (CAMs) Adhesion of cells to other cells and to the ECM is mediated by
certain proteins on the

Organelle Primary Function Essay
ant Cell
Organelle Primary Functions
1. Smooth ER The main function of the smooth Ers to make cellular products like hormones and
lipids.
2. Plasmodesmata The most important function of plasmodesmata is to connect cells together to
facilitate water transport.
3. Mitochondria The main function of mitochondria is to metabolize or break down carbohydrates
and fatty acids in order to generate energy.
4. Cell Wall The cell wall of plants maintains the shape of plant cells, supports/strengthens plants,
controls cell growth, acts as a physical barrier for the plant.
5. Cell Membrane A cell membrane protects the structures within the cell. Cell membranes are
semipermeable, meaning that only certain objects are able to pass through them
6. Cytoskeleton The cytoskeleton is a network of protein fibers that provide the framework for
cellular movement, shape, organelle movement and cell division.
7. ... Show more content on Helpwriting.net ...
Peroxisomes A major function of the peroxisome is the breakdown of very long chain fatty acids
through beta–oxidation.
8. Nucleus It stores the cell's hereditary material, or DNA, and it coordinates the cell's activities,
which include intermediary metabolism, growth, protein synthesis, and reproduction (cell division).
9. Chloroplast Chloroplasts' main role is to conduct photosynthesis, where the photosynthetic
pigment chlorophyll captures the energy from sunlight and converts it and stores it. 10.Ribosomes
Their main function is to synthesize proteins for use throughout the cell. 11.Rough ER The rough
endoplasmic reticulum is an organelle that produces proteins and helps them fold properly. 12.Golgi
Apparatus The primary function of the Golgi apparatus is to process and bundle macromolecules
like proteins and lipids as they are synthesized within the

Describe The Relationship Between Organelles And Eukaryotes
a.
Firstly, the cytoskeleton is one of the many membrane bound organelles which is only found in
eukaryotic cells and not prokaryotic counterparts. The cytoskeleton is a series of proteins within the
cell which provides the cell with shape and support. The cytoskeleton also mediates some aspects of
movement by helping the cell move in its environment and by controlling the movement of other
cell components. A second organelle which eukaryotes possess and prokaryotes do not possess
includes the Golgi apparatus. The Golgi apparatus initiates Golgi bodies towards modifying, sorting,
and packaging macromolecules for cell secretion (also known as exocytosis). The Golgi bodies also
modify and regulate proteins which are provided by the ER. In ... Show more content on
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Some the evidence for this theory include the mitochondria and plastids which can be identified in a
eukaryot; however, prokaryotes originally also have the same functional capabilities as the
mitochondria, as well as plastids. Perhaps the mitochondria's development is simply a result of
condensing the process of energy creation into a single organelle and the development of plastids
was a result of prokaryotes also being capable of completing a similar task; however, felt the need
for condensing this task into a single

How Does Adhesion Site Assembly Occurs While Nader Et Al
Constructing a picture or model for the particular situation (or modify one you find in one of the
papers or a review article).
Signaling pathways that result in cell migration are often useful in understanding how cancer cells
metastasize. The researchers of Swaminathan et al., 2016 examine how adhesion site assembly
occurs while Nader et al., 2016 focuses primarily on the adhesion turnover both are fundamental
processes in cell migration. Integrins play a dominant role in nascent integrin–mediated adhesions
(NAs) which are important in lamellipodium protrusion and generating traction at focal adhesion
points involved in cell motility. Integrins have been extensively studied and are linked to wound
healing as well as metastasis in cancer cells (Lawson et al., 2012). When extracellular signals, either
chemical or physical, contact the cell surface it triggers a response that induces movement. If the
signaling molecule is a growth factor (ex. Epidermal Growth Factor) it could activate a GTPase
protein coupled receptor (GPCR). The next is a signal cascade often led by Rabs or Ras (small G–
proteins) proteins that are powered by GTPase hydrolysis, which often recruits and activates
Wiskott–Aldrich Syndrome protein (WASP) or Scar. Previous studies identified cancer cell that use
Rab–coupling to control cell motility by regulating B–intgrins trafficking (Nader et al., 2016).
WASP recruits Actin related protein 2 and 3 (Arp2/3) complex to the cell membrane and activates it

The Major Cytotoxic And Carcinogenic Effects Of...
Microcystins are potent hepatotoxins produced by blue–green algae or cyanobacteria, which are
common in contaminated water. The most common type of microcystins is microcystin–LR (MC–
LR). This report will discuss the major cytotoxic and carcinogenic effects of microcystins, and how
these effects translate into hepatotoxicity. Additionally, cell–based assays will be proposed to
identify and examine the various hepatotoxic characteristics of cyanobacteria or blue–green algae
extracts which contain microcystins.
MC–LR is a cyclic heptapeptide and also a phosphatase inhibitor which specifically targets
serine/threonine phosphatases 1 (PP1) and 2A (PP2A) by directly binding at three sites before
forming covalent adducts.1 These phosphatase inhibitors cause hyperphosphorylation of
cytoskeletal proteins which results in the downregulation of actin and tubulin proteins, and the
upregulation as well as the downregulation of the intermediate filament proteins. Furthermore, a
study on hepatocyte response to microcystin toxin had shown a dramatic increase in 32P
phosphorylation in hepatocytes following exposure to cyanobacteria microcystins.2
Certain proteins of the MAPK superfamily are involved in cytoskeleton development and
maintenance.3 Various mechanisms of cytoskeletal disruption through MC–LR–induced PP1 and
PP2A inhibition (Figure 1) lead to the hyperphosphorylation of proteins downstream of MAPK. For
instance, while the heat shock protein 27 (Hsp27) usually exists as a large

Why The Cytoskeleton: The Most Important Organelles
The cytoskeleton is the most important organelle. Without it in place, all the other organelles inside
the cell would be randomly floating around with no sense of order. This would make the cell's job
much harder and could create multiple different outcomes, since the cells would not have the same
organelles in the same areas. The cytoskeleton keeps all the other organelles in the cell and in the
proper areas. The cytoskeleton also anchors the cell to its neighboring cell and to the protein
network in which that cell is sitting. This organelle provides the cells shape, which also provides the
function of that particular cell. The cytoskeleton additionally allows the cells to shrink and grow
very quickly.
Another function is the assisting of moving materials in and out of the cell. The cytoskeleton
facilitates movement through three main components which are microfilaments, ... Show more
The cytoskeleton has a very dynamic nature, because it is necessary for cells to change shape and
complete cell division, or migrate. In cell division, the cytoskeleton plays an essential role in equally
distributing the chromosomes into each of the new cells. Each of these self–assembling proteins has
"critical concentration," a characteristic concentration. In which, below is the monomer state and
then above is the polymer state. The concentration favors the building up of filament, and decreasing
the filament deconstruction. The allows the cell to quickly control the cytoskeleton structure.
One third that makes up the cytoskeleton are microfilaments. These are also commonly called actin
filaments. These are filamentous structures which are in the cytoplasm of eukaryotic cells and form
part of the cytoskeleton. When they are in cells which are modified by and also interact with
multiple proteins. Polymers of actin are what mostly make up

Cilia Essay
Cilia; An Essential Motility Centre Whose Defects Are Implicated in Many Diseases
In the summer of 1674, the Dutch scientist Antoni van Leeuwenhoek looked through a homemade
microscope at a sample of rain water and revolutionized the human view of the world. What he
found was "little legs" that we now know are the cilia that many single–celled protozoa use for
locomotion. Almost exactly 300 years later, the observations of Swedish scientists Afzelius led to
another paradigm shift, when he linked defects in the machinery required for the movement of
human cilia to Kartagener's syndrome (KS), a disease characterized by chronic sinus and respiratory
infections; male infertility; and, incredibly, the misplacement of the heart and other organs (Brown
& Whitman 2014). He too came up with the hypothesis that the existence of 'so–called sensory hairs
protruding from the cell surface into the extracellular space' was to explain the poor sense of smell
and decreased hearing ability in patients with KS (Pennekamp et al. Cilia 2015). Almost two
decades after Afzelius presented his ... Show more content on Helpwriting.net ...
The study of motile cilia has been very significant with a range of models and experiments that
scientists have conducted specifically for knowledge of the cells ambiguous occupation in the
human body. In comparison to the other study's conducted one stands out most of all. It is the the
algae, Chlamydomonas reinhartii, a biflagellate single cell organism whose cilia express a set of
proteins that provide a necessary function in the motile human cilia. The main causal difference in
types of cilia most likely derived from expression of sensory receptors on the motile cilia to attain
material from the environment. "It has been posited that enhanced specialization of cilia lead to the
development of complex sensory organs such as the retina" (Biosci

The Cell Number On The Nanotube With 30 Nm Diameter
Xianglong et al. found similar results (2) in their paper. The cell number on the Nanotube with 30
nm diameter was significantly higher than the one without the nanotubes. For each incubation time,
the surface with the absence of nanotubes had the least cell adhesion. Even with respect to the
filopodia the nanotubes showed similar behavior. On the surface withy nanotubes of 30 nm
diameter, the actin of the cells was organized along the spreading direction and had formed many
filopodia. Interestingly, most of the cells on the surface of 80 nm diameter group maintained a round
or oval shape, but the cells also stretched out many filopodia. Cells on the three nanotextured
surface had stretched out many filopodia and some lamellipodia. In particular, the cellular
cytoskeleton of cells on the 80 nm surface achieved a more homogeneous and extensive
arrangement compared with those of the other three groups. The shapes of cells grown on the SLA +
30 nm and SLA + 80 nm surfaces were clearly different. It was observed that those grown on the
SLA + 80 nm surface were the most irregularly shaped, while those grown on the SLA + 30 nm
surfaces had relatively regular shapes.
Gene expression on the titanium surfaces was quantified using RT–PCR.ALP expression level was
detected higher at week 1 and was subsequently greatly decreased at week 2. The expression level of
ALP in cells grown on the 80 nm surface was more than that in cells grown on other surfaces at all–
time points. The lowest

Cilia Function
Cilia are organelles protruding from body cells, consisting of microtubules. These structures are
important for hemostasis and cell development. Along with a group of proteins called kinesins
superfamily proteins (KSFs), the cilia also play an important role in SHH signaling. The proteins
found in this family serve a variety of functions relating to microtubule regulation, such as KIF4A
and KIF21A. KIF4A controls microtubule length during cell division, whereas KIF21A inhibits
microtubule growth at the cell cortex. A prominent member of this family is the protein KIF7, a
homologue of the protein Costal2 (Cos2) found in Drosophila and zebrafish. Both serve relatively
similar functions with relation to the Hh signaling pathway, though there ... Show more content on
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The level of activity of Gli genes, and thus Hh–pathway activation, determines skin tumor
phenotype: high level signaling is shown to result in BCC and low–level signaling is shown to result
in follicular derived tumors such as basaloid follicular hamartoma (BFH) (2). Gli2 is involved in the
expression of cell cycle regulation genes in the Shh–pathway such as E2F1, CCND1, CDC2 and
epidermal differential genes. Over–expression of Gli2 causes the up–regulation of such cell cycle
regulation genes in developing hair follicles. Shh–activation most specifically promotes degradation
of the p53 tumor suppressor gene (2), thus repressing transcription of p21, a key suppressor of
cyclin E in cell–cycle regulation. Thus, G1 arrest is overrode, and the inability to control cell cycle
is promoted: a key feature of cancer. Sufu and Kif7 have overlapping functions in regulating Gli
transcription factors. Specifically, Gli2 forms a complex with Sufu to prevent transcriptional activity
via preventing accumulation of Gli2 transcriptional factors into the nucleus, thus repressing Hh
pathway transduction (3). Sufu also plays a role in stabilizing Gli2 by blocking Spop, an E3 ligase
involved in degradation of Gli2 (3). In keratinocytes, Kif7

Cell Theory Research Paper
Cell structures are a very unique component in life. Cells have the ability to accomplish many tasks.
Theses tasks may include identifying genetic information, the gossamer endoplasmic reticulum
subway system and the fibril laced cytoskeleton. All of these parts are needed in order to have life.
Before all of this occurred, we developed a cell theory. The cell theory was basically used to explain
how every living thing is made out of cells. In the cell theory there were three principals that it
followed. The first principal was that all organisms are composed of one or more cell, and the life
processes of metabolism and heredity occur within these cells. The second was that cells are the
smallest living things, the basic units of organization ... Show more content on Helpwriting.net ...
The cytoskeleton consist of polymer of identical protein subunits that attracts one another and
assemble in long chains. In the cytoskeleton there are three different kinds of fibers. The three fibers
are actin filament, microtubules and intermediate filaments. Actin filament are composed of two
protein chains loosely twined together like two strands of pearls. Microtubules are the largest
cytoskeletal element and it is formed from nucleation centers near the center of the cell and radiate
toward the periphery. Meanwhile, the intermediate filaments is considered to be the most durable
element of the cytoskeleton. They are a mixed group of cytoskeletal

Skeletal muscle is necessary for locomotion and the...
Skeletal muscle is necessary for locomotion and the maintenance of posture. Without skeletal
muscle, which operates under voluntary control, humans would lack the ability to do the most basic
of tasks such as or standing or walking. A muscle is comprised of numerous muscle fascicles, which
consist of muscle fibers. These muscle fibers are composed of muscle fascicles, which The basic
unit of skeletal muscle is the sarcomere, which is comprised of myofibrillar proteins myosin (thick
filament) and actin (thin filament) which consists of Troponin and Tropomyosin, two important
proteins necessary for muscle contraction.1 Skeletal muscle contraction occurs as a result of
excitation–contraction coupling. Upon the arrival of a nerve ... Show more content on
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A greater cross–sectional area of the muscle will allow the muscle to produce more force when
activated.
An increase in cross–sectional area of a muscle is primarily due to muscle hypertrophy. Muscle
hypertrophy can be defined as an increase in myofibril size, and can be . Satellite cells can be
thought of as the stem cells of the muscle and play an essential role in exercise–induced muscle
damage repair.3 Satellite cells are located between the sarcolemma and basement membrane of
skeletal muscle fibers,4 and lay dormant in a mitotically quiescent state until the muscle any form of
trauma or injury due to overload.5 Within several hours of muscle damage, satellite cells are
activated as evidenced by increased cellular levels of MyoD and myogenin, two important
transcription factors involved in myogenesis.5 Satellite cell activation is Hepatocyte growth factor
(HGF)
Whether or not muscle fiber hyperplasia occurs in humans remains a controversial topic in exercise
physiology. Hyperplasia refers to a net increase in the number of muscle fibers in an individual
muscle. Numerous studies have shown that muscle fiber hyperplasia does occur in animals under
particular training protocol ( insert citation, and biefly decribe 2 of the studies) Although the
evidence supporting muscle hyperplasia in animals is vast,very

Prokaryotic Vs Eukaryotic Essay
Prokaryotic are organisms whose DNA is not confined within a membrane–enclosed nucleus.
Prokaryotic organisms are single, but some prokaryotic organisms are multicellular. Eukaryotes are
organisms who cells are organized into complex structures by internal membranes and a
cytoskeleton. (Cundy, 2012) The most characteristic membrane bound structure is the nucleus.
Animals, plants, fungi, and protists are eukaryotic. Prokaryotic organisms are typically between 0.1
to 5.0 um in size while Eukaryotic organisms are between 5–10 um. Prokaryotic organisms have
pili, cytosol, ribosomes, capsule, cell wall, plasma membrane, DNA, and chromosome also known
as plasmids. (Cundy, 2012) They do not have a nucleus, lysosomes, microtubules, endoplasmic
reticulum, ... Show more content on Helpwriting.net ...
This is what allows prokaryotes to attach to other surfaces. Cytosol is a water like fluid found in the
cytoplasm. Cytoplasm is inside the plasma membrane but outside the nucleus. The cell wall is made
of polysaccharides just outside the plasma membrane and its made of cellulose. (Cundy, 2012) The
plasma membrane is the outer boundary of the cell with a layer made of phospholipids. DNA is a
double polymer of nucleotides that store genetic information. DNA stands for Deoxyribonucleic
Acid with a phosphate group of four nitrogenous bases which are adenine, cytosine, guanine, and
thymine. The largest organelle is the nucleus. The nucleus contains DNA. The mitochondria have a
double membrane and it is known for supplying energy to the cell. Ribosomes produce proteins.
These ribosomes can be found in the cytosol of cells. The nucleolus is what makes ribosomes and
RNA. Lysosomes have digestive enzymes. The endoplasmic reticulum is an inner membrane system
that makes some proteins. (Cundy, 2012) There are two endoplasmic reticulum, one is rough and the
other is smooth. The rough endoplasmic reticulum has ribosomes on it while the smooth
endoplasmic reticulum does not have ribosomes on them. The Golgi apparatus prepares proteins to
be taken out of the cell. The vacuole is storage for water and other nutrients a call may need and this
is most commonly found in plant cells. The cytoskeleton shapes the cell wall and consists of protein

Cytoskeleton Lab Report
Just finished discussing and letting the statistic guy checking our histogram. Please see the
powerpoint and the excel file for the histogram.
Yes, we do have a bimodal distribution, which I think it could be the mechanism of the cytoskeleton
in responding to the mechanical strain –– during the small strain the cytoskeletons could respond to
the change, however, at the high strain the cytoskeleton gradually improves their structures by
aligning themselves in more towards one preferable direction and binding themselves together as a
bundle through cytoskeletal actinins (ACTn1) as a mechanism to withstand the high strain.
However, all these mechanisms still need to be tested, which we may not sure if we have enough
time to do in 4wks.
For the blebbistatin, it's true that it could be a quick experiment to run. However, I think it's a bit of
making an assumption (––like I just did it above) because the true inhibition of the blebbistatin is at
the myosin2 not at the cytoskeleton itself nor the forming of actinins (ACTn1) plus our gene
expression array can have so much gene on in one array and we did kinda scout through the myosin
in general (not looked into any specific myosin isoforms). (For example, one of the reasons could be
because our results have shown that after LIV the expression of ACTn1 level is highly up–regulated
as reciprocally seen in the increasing bundle and fiber– alignment in our images though the
upregulated in the immediate response is much difference than the upregulated level in the longer
period, which could suggest the

The Structure And Function Of Myocytes. Ian Pittwood....
The Structure and Function of Myocytes
Ian Pittwood
Missouri University of Science and Technology Introduction Even some of the most basic of
organisms can move. In multicellular organisms, there can exist cells that alter their size and shape
to promote this movement. These cells are then grouped into muscle tissue that can work together to
create motion in the organism. One of these cells, the myocyte from skeletal muscle, will be covered
in this paper. I chose this cell as I am an avid weightlifter and would like to investigate more into
how muscle cells are structured and how they function. I believe that this knowledge could make me
more effective in the gym.
Structure
Myocytes when first discovered had such an unusual structure ... Show more content on
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The membrane for myocytes is stretched into a longer form with fibers at the end that combines
with surrounding muscle cells. The sarcolemma also has pores on its surface that extend into T–
tubules that wrap muscle fibers and can transfer an action potential from motor neurons to the fibers.
(Saladin, 2012) Unlike many other cells, muscle cells only appear strung together in fibers. The
nucleus or nuclei of a fiber is pushed up against the edge of the membrane to make room for
myofibrils within the cell. Myofibrils within the cell are part of the cytoskeleton and contain
filaments of actin and myosin that work to move the muscle. These myofibrils have repeating
patterns that appear as bands on muscle fibers. Each of these repeating sections is known as a
sarcomere. These fibers cause the overall shape of the myocyte to be long and tubular. (Liner, 2017)
Figure 1 and 2 above display a confocal image of muscle fibers with a motor neuron and a diagram
of a muscle fiber. On Figure 1 the green neurons can easily be can the yellow/orange nuclei for the
muscle cell. Figure 1 displays how randomly placed the nuclear as well as the sheer size of the
muscle fibers. It also displays how neurons are linked into the T–tubules of the cell. Unfortunately
figure 1 does not yield much information about the detailed internal structure of the myocyte. The
diagram in Figure 2 creates a much more detailed figure that shows not only the nuclei bordering

Eukaryotic Cell Functions
All eukaryotic cells have microtubules, which are hollow rods assembled from a globular protein
called tubulin. Microtubules grow in length by adding tubulin dimers. Those dimers can also be
disassembled, which would allow the tubulin to build microtubules elsewhere in the cell. The two
opposite ends of of a microtubule are actually pretty unique. One end can can accumulate or release
tubulin dimers at a much higher rate which allows it to grow or shrink during cellular activities
(Campbell, pg.114). The microtubules and the motor proteins of a cell are closely related, which is
why I must introduce some of there functions. Cell motility generally requires interaction if the
cytoskeleton with motor proteins. They work together with plasma ... Show more content on
Helpwriting.net ...
Now we are presented with microtubules again and this time I shall describe to you why this is part
of the correct choice. As microtubules structure actually serves as tracks, which organelles that are
equipped with motor proteins can use to move. That seems like one of the two functions we were
looking for that contribute to movement within a cell. Microtubules are often handled with the task
of guiding vesicles from the ER to the Golgi apparatus (Campbell, pg. 114). The next part of choice
B is motor proteins, which are often compared to as feet or how the cell walks to their destination.
They use the tracks provided by the cytoskeleton. The motor protein kind work with the
cytoskeleton and the plasma membrane molecules, which allow whole cells to move along fibers on
the exterior portion of the cell (Campbell, pg.113). Choice B is correct.
Choice C. I don't want to repeat myself and sound repetitive so I tried to give a detailed response to
choice A as to why actin filaments is incorrect. Actin filaments is more of a structural component of
the cell aiding it in bearing tension (Campbell, pg. 114) Motor proteins I tried to give a detailed
description in choice B as to why it is correct. Motor proteins work with various parts of the cell to
allow whole portions of a cell to move along fibers outside the cell (Campbell, pg.113). Choice C is

Functions Of A Cilia Of Cilia And Contractile And Motor...
The various known functions of a cilia are to circulate fluids, move eggs into the oviduct, line air
passages to sweep out mucus that contain bacteria, and many more (Erster Lecture 6). Cilia are
about 2–20 um long, and they are extensions of cells that perform in locomotion (Campbell pg. 12).
They can be found in multiple eukaryotes such as Paramecium (which are found in pond water) to
humans. In the single–celled organism, Paramecium, the cilia helps propel it through the water. As
for humans, the cells in the our windpipes are lined up with cilia and they prevent the lungs from
bacteria by sweeping a film of debris–trapping mucus upward (Campbell pg. 12). Various proteins
within the body has they own function, and the contractile and motor proteins are responsible for the
movements of cilia and flagella (Campbell pg. 76). CIlia must be motile in order for them to
perform their functions, thus when the cilia are immotile, a syndrome known as Kartagener 's
develops through the rare genetic disorder of the immotile cilia. Since cilia deals with motion, when
males are afflicted with Kartagener's syndrome they become sterile from the immotile sperm, and
they often also suffer from lung infections (Campbell pg. 118). However, this syndrome can also
affect females. It can lead to infections at the nasal sinuses and bronchi for both genders. An
interesting effect of Kartagener 's is situs inversus, which is the "reversal of the normal left–right
asymmetry of the organs in the

Research Paper On Sickle Cell Disease And Cytoskeleton
Sickle Cell Disease and the Cytoskeleton
The cytoskeleton helps the cell keep its shape, helps in cellular movement, and helps with internal
movement. The cytoskeleton is only found in eukaryotic cells and is a network of protein filaments
and tubules that extends throughout the cytoplasm. Microtubules help form structures such as cilia
and flagella, which help single–celled organisms move, and the spindle . The cytoskeleton is a
system of intercellular filaments necessary for cell shape, division, and function. The cytoskeletons
of prokaryotes show plasticity in composition, with none of the core filament–forming proteins
conserved in all lineages. Eukaryotic cytoskeletal function

Why Actin Is A Protein Of Any Cell
Actin
Introduction:
Proteins are the primary functionary macromolecules of any cell due to their vast variety in function,
which is a result of their amount of varying forms, and they are polymers composed of amino acids.
These functions include transportation, structural support, motility, gene regulation, signal carrying
and receiving, storage, and catalyzing reactions; these functions are determined by the form of the
protein. It follows then that the many functions of proteins come from their multitude of forms and
their multiple levels of structure which are as follows: primary, secondary, tertiary, and quaternary.
The primary structure is most basic chain or sequence of amino acids that accumulate into the alpha
helices and beta sheets which compose the secondary structure of a protein. The tertiary structure is
a complete and three–dimensional polypeptide chain containing the secondary structures, folds,
coils, loops, and such that form a globular form. Quaternary structure is a single protein formed by
multiple polypeptide chains or multiple tertiary structures.
General Information on Actin:
Actin is a protein of moderate size that was discovered in an extraction of rabbit muscle tissue by
Bruno Ferenc Straub. Actin is the component of actin filaments which are a major component in the
cytoskeleton. This actin cytoskeleton that structurally supports the cell membrane is quite important
to the morphology of a cell due to its spread, abundance, and general size; it can

Myo1c
Myo1c, a non–processive actin motor protein in the myosin family, has been localized in cell as part
of the intercellular transport system. Specifically this protein has been found trafficking cargo on
actin filaments, although their role is not fully understood or researched. Myosin–1 proteins have
single heads and they are used to help interactions with actin and the membrane system of the cell.
Some examples of their jobs in the cell is "to recycle lipid raft cargos, and final glucose transport."
Many scientists believe myo1c is a tethering protein, or it is a slow transporter. Myo1c has a major
role in kinesin–1 and TM2 interactions in–vitro cell cultures. Studying the Myo1c interactions
would provide scientists with a better understanding ... Show more content on Helpwriting.net ...
The in vitro cell cultures were used first to determine the role in Myo1c in the start and ending for
kinesin–1 transport on the actin filament and microtubule intersection. By tagging the kinesin–1
with fluorescences and placing the protein attached in environments with or without Myo1c, there
could be an investigation on how the protein moves a synthesized cargo around the cell. From these
results, it is noticed that Myo1c is helpful in the initiation of kinesin–1 runs on microtubules. The
cargo docking at the AF intersections were shown to be specific to Myo1c. By using α–actinin to
stop cargo at the same point as Myo1c, there was a distinct difference in the efficiency of pause in
transport. This results of the α–actinin caused stops were shorter and less frequent than the Myo1c
caused stops supporting the thought that these distinct stops are unique to Myo1c motor proteins. In
order to test the effect non–muscle tropomyosins have on the Myo1c motor proteins experiments
looking at the interaction between full length Tm2 and Myo1c, and how this interaction changes the
AF/MT intersection were performed. Testing the Tm2–actin gliding inhibited how in the presence of
Tm2, the Myo1c was prevented from pausing the cargo as it approached the Tm2–AF/MT

Organelles In Animal Cells Essay

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