Spindle MT Dynamics

Spindle MT Dynamics
Microtubule
During mitosis, MT dynamics dramatically increase and the formation and tension of kinetochore
MTs is important for the correct attachment with the centromere, separation of tetrads, and
segregation of chromosomes (24). Indirect evidence suggests that the common mechanism
underlying the inhibition of spindle MT dynamics, results in the deceleration of the metaphase–
anaphase transition, defective segregation of chromosomes, mitotic block and subsequent induction
of the mitochondrial pathway of apoptosis.(24, 25)
DATS basically mediates in thiol/Disulfide exchange by redox modification of specific reactive
cysteines resulting in thiolyation of the protein like actin microfilament and β–tubulin causing
depolymerization of actin filament and microtubule leading to M–Phase cell cycle arrest.(26)
Hosono et al. demonstrated that treatments with DATS induced an increase in the molecular weight
of Mt subunit, tubulin by 71.2 Da, which corresponds to the mass of the fragment of mercapto–allyl
group originating from DATS, as well as from SAMC, indicating that S–allyl adducts to Cys12beta
and Cys354beta are the main event in triggering microtubule network disassembly and inducing
interphase arrest.(27)
It was reported that SAMC, but not S–allyl–cysteine (SAC), is able to interfere with microtubule
polymerization ... Show more content on Helpwriting.net ...
On the basis of structural composition, the presence of numerous reactive cysteines residue on actin,
it cannot be excluded that allyl compounds may induce redox modifications also at the actin level.
Based on theinvolvement of cytoskeleton in NAD(P)H oxidase activation, as well as in cell
adhesion and motility, it could have a critical role in the induction of cell cycle arrest and apoptosis
by destabilizing the imperative cytoskeletal filaments of the
... Get more on HelpWriting.net ...

Is Cancer A Dangerous And Fatal Diseases?
Cancer is one of the most dangerous and fatal diseases, which is caused by uncontrolled growth and
proliferation of cells. Cancer cells' survival, progression and metastasis are tightly associated with
the cellular components. For example, when cells metastasizing, they use cell protrusion which
provided by actin cytoskeleton to penetrate the extracellular matrix, they also secrete plasminogen
activator to increase protease plasmin's activity in order to penetrate the membrane. Then some of
the tumor cells transfer to another tissue and form metastatic tumor. The specific functions of
several cell structures and transporters in tumor cells are discussed as follows.
Lysosome plays important role in cells' behavior, it not only the degradation and recycle place for
cells, but it also associated with cellular processes such as autophagy and signaling. Especially in
cancer cells, the lysosomes are greater in number, larger, more active than normal cells. [1] The
mechanism for lysosome in cancer cells is that lysosome can release certain cathepsins, which is a
kind of virtual acidic hydrolases from tumor cells into the extracellular space, which lead to cancer
cells' progression and death by apoptosis and apoptosis–like pathways. [2] On the one hand, the
cathepsins contribute to the degradation of intracellular substrates, regulation and recycle of
extracellular substrates. On the other hand, the cathepsins control degradation of secretory proteins
by crinophagy and degradation

Advantages And Disadvantages Of Vincristine
Most natural products are generated from plants because they have the "broadest spectrum of
biosynthetic capability"(Lokanatha M. K. Prof). Natural products play a very pivotal role in the
identification of compounds that are essential in the treatment of many devastating ailments such as
cancer. Vincristine is an example of a lead anti–cancer compound that is derived from plant.
Vincristine is from a class of vinca alkaloid that is derived from the plant Catharanthus Roseus.
Catharanthus Roseus is also known as periwinkle and is popularly found in Madagascar. It is used
for decorative purposes in Jamaica and other countries. Furthermore, this essay seeks to expound on
the pharmacologically useful compounds isolated from Catharanthus roseus, the pharmacological
use of the isolated compound (vincristine), the chemical ... Show more content on Helpwriting.net ...
The mitotic spindles are predominately found in the metaphase stage of the cell cycle and as such it
is targeted by vincristine. Vincristine binds and crystallizes microtubular protein to cause an arrest of
cancer cells undergoing division and thus apoptosis. Vincristine is specific for rapidly dividing cells
and cancer cells are examples of such cells. Furthermore, it is important to note that vincristine have
side chain which are responsible for its anti–cancer effect. Two of such side chains are the acetyl and
the hydroxyl. In animal studies it is observed that the hydrolization of the acetyl group and the
acetylated of the hydroxyl groups will obliterate the anticancer potential of vincristine. This is
because modification of the molecules will wholly change the structure of vincristine. The discovery
of pharmacological compounds from plants has been a great achievement in the synthesis of life–
saving therapeutic agents. Unfortunately, there is no analogue of

Nocodazole Effect
Nocodazole is a synthetic tubulin–binding agent. It inhibits mannose efflux by preventing and
disrupting microtubule assembly and disassembly. This results in the prevention of mitosis and
induction of apoptosis in tumor cells. The more nocodazole present, the more mannose efflux was
inhibited. For example: in Figure 4a. efflux of mannose is over four times greater when there is no
nocodazole than when there is 25 µM. The effects were also shown to increase as the amount of
exposure time increase. At 30 minutes to efflux of mannose is around 20 cpm/µg. But at 60 minutes
the efflux has risen to over 80 cpm/µg. It is concluded rapid efflux of mannose out of the Golgi
Apparatus occurs through a nocodazole–sensitive transporter. In the article, Sharma and Freeze
believe paclitaxel should stabilize and reverse the inhibitory effect of nocodazole, however this is
not the case. Paclitaxel binds to tubulin and inhibits the disassembly of microtubules, thereby
likewise inhibiting cell division. It also induces apoptosis by binding to and blocking the function of
the apoptosis inhibitor. It was found in Figure 4b. the presence of both nocodazole and paclitaxel the
movement of compounds by mannose is less than when only nocodazole is present. ... Show more
content on Helpwriting.net ...
illustrates mannose cells with no treatments applied. In this picture the mannose cells contain
microtubules. Figure 4d. shows are cells treated with only paclitaxel. These cells have intact
microtubules. Figure 4e. is of cells treated with nocodazole. These cells cannot be seen because
nocodazole has caused the depolymerization. This means polymers are converted into a monomer or
a mixture of monomers. Figure 4f. is similar to 4b. in that mannose cells are treated with both
nocodazole and paclitaxel. These cells have microtubules present. This is due to paclitaxel
stabilizing the effects of nocodazole. This means mannose cells in the presence of paclitaxel and
nocodazole have intact microtubules but the efflux is

Eukaryotic Of Eukaryotic And Eukaryotic Genomes
I. Introduction
Perhaps one of the first lessons one is taught about bacteria is that they constitute the prokaryotic
domain of life, while humans and most other readily visible life forms are firmly rooted in the
eukaryotic domain. These domains diverged many millions of years ago from a common ancestor
and, while the eukaryotic branch later split into eukaryotic and archaeal domains, it maintained its
separation from the prokaryotic domain (Woese et al., 1990). Prokaryotic and eukaryotic genomes
are naturally very distinct in both content and structure as a result of eons–long separation, and one
tends to classify these domains as very distinct entities.
However, there is increasing evidence of so–called eukaryotic bacterial genes, or genes present in
bacterial genomes that have some sort of eukaryotic origin or function. These eukaryotic bacterial
genes are primarily of concern in determining virulence factors of human pathogens. As defined
below, bacterial genes can be evolutionarily or functionally eukaryotic, or both. Presence of either
type of gene would indicate some interaction between bacteria and eukaryotes, the most oft studied
of which are pathogenic interactions. Discovering eukaryotic bacterial genes is particularly
important in pathogens that secrete effectors to be taken up by host eukaryotic cells. These effectors
tend to modulate host cell functions, so there would be some logic in these effectors being encoded
by eukaryotic genes. Most research has been

Cdp Lab Report
CDDP Induces Phosphorylation of TRAF6 Reducing Ubiquitination in the Cytosol Genotoxic
stresses are hypothesized to reduce K63–linked ubiquitination of p53 which would then cause
TRAF6 to not be recruited. K63–linked ubiquitination of p53 was assessed through stimulation with
the genotoxic stress agent CDDP. To test this hypothesis, an immunoprecipitation assay of mouse
embryonic fibroblasts (MEFs) was used to observe p53 ubiquitination in the cytosol of wild type
and TRAF6 knockout cells in the presence of CDDP for 4 hours. P53 was blotted as an input to
ensure presence. This assay shows that K63–linked ubiquitination of p53 was only observed in wild
type MEFs in the cytosol indicating that TRAF6 is necessary for K63–linked ... Show more content
on Helpwriting.net ...
In an immunoprecipitation assay, 293T cells testing wild type and mutated TQ/SQ sites in TRAF6
was utilized to determine the effect of genotoxic agents on the phosphorylation of TRAF6 at TQ/SQ
motifs. The authors immunoprecipitated for flag asTRAF6 was tagged with the flag antibody. CDDP
and ATM/ATR were used as our tested variables. The assay elucidated that the double mutation of
S13 and T330 on TRAF6 significantly reduced phosphorylation of TRAF6 in the presence of CDDP
and absence of ATM/ATR. Consequently, this data provides information for belief that mutated
TRAF6 is not sufficient for phosphorylation to occur in the presence of CDDP. Finally, a cellular
fractionation assay for 293T wild type and mutant TRAF6 cells with or without CDDP treatment
tested whether such mutation in the presence of genotoxic stress inhibits or promotes TRAF6
expression. As in the previous fractionation studies, tubulin and laminB were loading controls.
These results concluded that the mutant displayed resistance to the CDDP mediated reduction of
TRAF6 in the cytosol. Overall, these studies suggest that CDDP induces phosphorylation of TRAF6
in the cytosol, which may contribute to the reduction of K63–linked ubiquitination in the cytosol.
The information provided thus far suggests that K63–linked ubiquitination of p53 is accomplished
by TRAF6, which is hypothesized to suppress spontaneous apoptosis. Moreover, genotoxic stress is
shown to promote TRAF6

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

What´s the Exact Cause of Cancer?
Cancer is a disease where there is uncontrolled cell division and surrounding tissues are invaded.
This invasion occurs by a process called metastasis; cells grow directly into surrounding tissues and
are transferred through the bloodstream or lymphatic system. These rapidly growing cells are
supported by angiogenesis, the growth of new blood vessels from old ones, which helps supply the
cells with nutrients.
Cancer results from cell mutations which stem from DNA damaged during the cell cycle. These
mutations are in genes that encode for proteins that control cell division. The uncontrolled division
of cells results in the growth of benign tumors or malignant tumors. Benign tumors do not undergo
the process of metastasis and are seldom life–threatening. Malignant tumors do undergo metastasis
and are very life–threatening. The exact causes of cancer are still undetermined, but there are many
things that raise the chances. Smoking and drinking has been linked to many cancers such as lung,
mouth throat, bladder, and kidney cancer. Radiation and too much exposure to sunlight can also lead
to cancer. It is known that changes in cells cause cancer but what causes these changes are unknown.
The cell cycle is the link between the unknown cause and cancer.
The cell cycle is the cycle of cell growth, replication of the genetic material and division into equal
daughter cells. The cell cycle consists of interphase and mitosis. Interphase has three steps; G1, S,
and G2

The Organization Of Microtubules ( Mts )
The organization of microtubules (MTs) in the mitotic spindle apparatus has been shown to involve
a combination of centrosomal–based nucleation and hypothesized to involve acentrosomal
branching MT nucleation. Here, Petry et al. (2013) uses Xenopus egg extracts to successfully
observe branching MT nucleation from existing microtubules utilizing total internal reflection
microscopy (TIRF). Direct observation of branching MT nucleation highlighted both the activating
effect of RanQ69L and its effector protein TPX2 on branching MT nucleation, and the polarity
conservation of daughter MTs. Testing for required molecular factors using immunodepletion, it was
shown that the γ–tubulin ring complex (γ–TuRC) is required for primary nucleation while the
protein complex augmin is required for branching. Furthermore, components of the RanGTP
signaling pathway are shown to induce observed branching MT nucleation. The results by Petry et al
clearly demonstrate branching MT nucleation and is a significant achievement, being the first ever
visualized in a metazoan system. Further research should focus on deciphering the mechanistic
interactions between that RanGTP and TPX2, specifically its C–terminus CT–TPX2, that stimulate
MT nucleation. In addition, even though augmin has been shown to play a key role in spindle
morphogenesis through branched MT nucleation, its relationship with other molecular factors
should be further elucidated.
Background
Mitosis and meiosis are key cellular

Cytoskeleton
The cytoskeleton is a structure that contains a complex microscopic network of protein, which
comprises the cytoskeleton with 3 primary types of fibers, actin filaments which are commonly
known as microfilaments, intermediate filaments and tubules (also called microtubules).
Microfilaments are the thinnest/finest of all the filaments and are about 3–6 nm in diameter.
Microfilaments are composed of contractile globular protein known as actin. They are also
responsible for movement as it is associated with myosin which is a protein responsible for muscle
contraction. Intermediate filaments are mid–sized proteins as the name suggests usually measuring
8–12nm in diameter. These filaments are constructed from a number of different subunit proteins
namely desmins, keratins, laminins and vimentin. Intermediate filaments play a structural role by
providing strength to cells and tissues instead of cell motility. Tubulin proteins have a cylindrical
shape, comprising alpha and beta subunits polymerized into microtubules. ... Show more content on
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Furthermore FtsZ also demonstrates GTP–dependent filament formation just as tubulin does.
MreB is a bacterial protein that is believed to be analogous to actin found in eukaryotic cells. This
protein is mainly found in non–spherical bacteria which assist in shape determination. Unlike FtsZ
and tubulin similarity, MreB and actin have a weak primary structure similarity, but relatively high
similarity in terms of 3–dimensional structure and polymerization of filaments.
Just as actin is related to MreB and tubulin to FtsZ, intermediate filament in eukaryotic cells have a
homologue known as crescentin. Crescentin was found in an aquatic bacterium recently and just like
intermediate filaments, this protein is organized into filaments in a helical structure. Furthermore the
primary homology is higher together with the 3–dimensional structure

STD: Trichomonas Vaginalis
Trichomoniasis is a type of STD that you get from a parasite called Trichomonas vaginalis. It is
mainly common in women but can also be found in men. The protozoan is very tiny, ranging from
approximately 7 to 15 mm, and cannot be seen with the human eye but the size may vary. It appears
to be more oval shaped but of course can change to certain conditions. The parasite has a unique
structure with five flagella helping with movement, one of them inside the membrane helping with
direction. Its cytoskeleton is made up of two main fibers, tubulin and actin which also help with the
movement. The nucleus is actually located near the head of the parasite. The axostyle ,which is a
thin structure that looks like a rod, starts at the nucleus cutting

Muscle Myopathy Case Study
Actin Filaments
Actin mutations can cause dysfunctioning of actin filaments. These dysfunctions of actin filaments
are mostly affect the dynamicity of actin filaments rather than complete disruption of actin
filaments, and can lead to muscle myopathies and compromised immunity.
Muscle myopathy is a disease in which the skeletal muscle in human body weakens and difficult to
move (Carnell et al., 2012). This disease can also affect the smooth muscle in respiratory tract that
leads to shortage in oxygen and carbon dioxide accumulation in blood. This disease is caused by the
mutation of ATP–binding activity of actin filaments. Therefore, muscle contraction cannot occur,
being that ATP is essential for the muscle to contract. There is no effective cure for this disease
(NINDS, 2015). However, some treatments can be done to overcome the weakness of the muscle.
Treatment for this disease is based on the muscle condition of the patient. Some physical therapy
and using brace as a support of the muscle can help the patient who ... Show more content on
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This disease is known as Wiskott–Aldrich syndrome. This disease is caused by the mutation of
Wiskott–Aldrich syndrome protein (WASP) gene that results in the loss of WASP and disruption of
actin filaments. This will affect white blood cells motility and can cause immunodeficiency. Some
treatments and therapies can be effective to cure this disease (Cooper et al., 2003). Hematopoietic
stem cells transplantation from a matching donor can restore white blood cells function.
Hematopoietic stem cells include bone narrow and peripheral blood cells. Gene therapy is also an
effective way to treat immunodeficiency. This therapy is done by engaging extracellular cytokine
ligation to the gene that will modify the transcription program of the white blood cells, resulting in
motile white blood

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
content on Helpwriting.net ...
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,

Taxol and Docetaxel Revisisted
The development of taxol and docetaxel into two of the worlds most important anticancer drugs
(Taxol® and Taxotere®) has proven the stabilization of cellular microtubules to be a clinically
relevant mechanistic principle.
Microtubule stabilization thus also provides a promising conceptual framework for the future
discovery of new and improved antitumor agents and this is not in the least reflected in the
significant number of new agents (taxane and non–taxane based) that are currently undergoing
clinical evaluation in humans.
Until the recognition of the tubulin–polymerizing activity of epothilones in 1995, the capacity for
microtubule stabilization appeared to be associated solely with taxol–like structures, but the last
decade has witnessed the discovery of a number of new and structurally diverse microtubule
stabilizing agents, which do not bear any structural resemblance with taxol.
These compounds are all characterized by the ability to induce tubulin polymerization in vitro and
their gross cellular profiles are similar.
At the same time, it is becoming increasingly clear that not all microtubule stabilizers are made
equal and that differences exist between individual agents with regard to their interactions with
tubulin, in the way they affect the cellular microtubule network and in their effects on cell
proliferation and the induction of apoptosis.
This includes, e.g., the discovery of compounds which do not bind to the taxol site on b–tubulin or
the identification of

Malignant Progression Of A Malignant Disease
Abstract The ability of cancerous cells to migrate from their primary site and invade a secondary site
is a hallmark of malignant progression. The invasive potential of a tumor hinges on the rigidity of its
epithelial microenvironment in vivo, or the stiffness of the matrix on which the cells are grown in
vitro. The serine/threonine protein kinase Cα (PKCα) promotes cell movement and contributes to
tumor invasion, partially due to its activity on two newly discovered substrates, CEP4 and α6–
tubulin. We set out to characterize the role of these PKCα substrates in the invasive phenotype of an
aggressive metastatic mammary carcinoma cell line LM2–4175. We hypothesized that
phosphorylation–resistant mutants of CEP4 and α6–tubulin would decrease the invasive phenotype.
To test this, we transiently transfected LM2–4175 cells with either wild type or phosphorylation–
resistant CEP4 or α6–tubulin and studied their migratory efficiency in transwells fitted with matrices
of differing stiffness. In parallel, cells were treated with a PKC activator. As predicted, migration
was potentiated by stiffer matrices under all conditions, with the exception of cells transfected with
phosphorylation resistant CEP4 and α6–tubulin where the invasion in the softer matrix was greater.
Furthering our understanding of the individual contributions of substrates of PKCα holds clinical
promise, as it will permit the development of novel targeted therapeutics to curb cell migration and
metastasis.

Results And Discussion Of Pcr And Dsrna Production Essay
RESULTS AND DISCUSSION PCR and dsRNA production Target sequences of 1501, 1576, 1650,
1750, 538, and 716 bp specific for gyrase A, gyrase rpo B1, rpo B2 and GFP were successfully
amplified with PCR (data not shown).. The in vitro transcription using T7 enzyme resulted in target
specific dsRNA of 1501, 1576, 1650, 1750, 538, and 716 bp for each of gyrase A, gyrase B, rpo B1,
rpo B2, L11, and GFP genes, respectively (Fig.1). In vitro growth inhibition assay B. bovis growth
(Fig. 2) from an initial parasitemia of 1% was significantly (ANOVA) inhibited at 10 µg/ml and 50
µg/ml concentrations of gyrase A, gyrase B, rpo B1 and B2, and L11 (Fig. 2). Treatment with a
mixture formed of 10 µg/ml gyrase A and 10 µg/ml gyrase B significantly inhibited the growth
(ANOVA, P < 0.01). The mixture formed of 10 µg/ml rpo B1 and 10 µg/ml rpo B2 resulted in
significant inhibition of the growth (ANOVA, P < 0.01) (Fig. 2). The single treatment with 10 µg/ml
or 50 µg/ml of each of the dsRNA of gyrase A, gyrase B, rpo B1, rpo B2, and L11 (Tukey–Kramer
HSD) did not show significant difference. There was no significant difference between the single
treatment with 10 µg/ml or 50 µg/ml of each dsRNA and the mixture formed of 10 µg/ml gyrase A
and 10 µg/ml gyrase B dsRNAs and the mixture formed of 10 µg/ml rpo B1 and 10 µg/ml rpo B2
dsRNAs

Midterm Review Bio
Biology Final Exam Review Sheet
a) The identity of each element is defined by the number of protons in its nucleus
a. The physical and chemical properties of each element are defined by:
i. Number of protons and neutrons in the nucleus ii. Number of electrons orbiting the nucleus
Proton = mass of one & a positive charge
Neutron = mass of one and no charge
Electron = negligible mass and a negative charge
Isotopes of an element
a) Isotopes are different forms of the same element
a. Same number of protons
b. Same number of electrons orbiting
c. Different number of neutrons
Chemical Bonds & Interactions
a) Covalent bonds – sharing of electron pairs
b) Ionic attraction – attraction of opposite charges
c) Hydrogen bond – ... Show more content on Helpwriting.net ...
Nuclear division occurs during mitosis
2. Cell division – cytokinesis – occurs at the end of the M phase (mitosis)
3. Cells that do not divide are usually arrest during G1 phase
4. DNA synthesis (S) DNA is replicated during S phase
5. G2 phase
In M phase (Mitosis), the DNA and proteins in each chromosome form highly compacted structures
In an Interphase nucleus, chromosomes are threadlike structures

Vinca Alocar Cells: A Case Study
1(i)High, because the appendix locates in abdominal cavity and near the right lower limb.
(ii)Low ,because the lungs locate in thoracic cavity.
(iii) Low,even though liver locates in abdominal cavity, it is not too near the right lower limb and it
locates in epigastric region.
2. Vinca alkaloid molecules bind to the tubulin, preventing its formation. Tubulin in cells is to make
spindle fibers which are microtubules. These microtubules provide cells with both flexibility and
structure so they are flexible enough to divide and copy. Without spindle fibers, cells cannot divide.
The vinca alkaloids prevent cancer cells from dividing successfully.As hair follicle cells need to
divide continually in order to produce new cell that form hair ... Show more content on
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In bone,the calcium makes the bone stay strong so it can be hard enough to protect oragans like ribs
protecting the heart , lung and enable it to provide support to our body like femur.In muscle,
contraction and relaxation of the muscles occur due to quickly changing concentrations of calcium
inside the muscle cells. Calcium will turned thin filament into an activated state through binding to
troponin. The binding of between calcium and troponin changes its shape then the myosin binding
sites on the actin are exposed so we can have movement and produce heat when the skeletal muscles
contract. When the skin becomes broken, calcium works together with vitamin K and a fibrinogen in
the clotting cascade.In contrast, without enough levels of calcium , blood will take longer to
clot,then it will increase the chance of inflammation as the pathogens can get into body through the

Symptoms And Treatment Of Cancer
Docetaxel also sold as Taxotere or Docecad, is a settled threatening to mitotic chemotherapy
pharmaceutical that works by intruding with cell division. Docetaxel is affirmed by the FDA for
treatment of secretly advanced or metastatic chest infection, head and neck development, gastric
tumor, hormone–adamant prostate danger and non small cell lung disease. It works by preventing
the disease cells from isolating into 2 new cells, so it obstructs the development of tumor. Docetaxel
ties to microtubules reversibly with high fondness and has a greatest stoichiometry of one mole
docetaxel per mole tubulin in microtubules. Docetaxel can be used as a lone administrator or in mix
with other chemotherapeutic pharmaceuticals as shown depending upon ... Show more content on
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Systemic treatment is regularly utilized as a part of conjunction with different modalities that
constitute "nearby treatment" (i.e. medications whose adequacy is limited to the anatomic territory
where they are connected) for growth, for example, radiation treatment, surgery, and/or
hyperthermia treatment. The adequacy of chemotherapy relies on upon the sort of tumor and the
stage. The general viability ranges from being corrective for a few growths, for example, some
leukemias, to being inadequate, for example, in some mind tumors,to being unnecessary in others,
as most non–melanoma skin cancers. Clinical information has indicated docetaxel to have cytotoxic
movement against bosom, colorectal, lung, ovarian, prostate, liver, renal, gastric, head and neck
tumors, and melanoma. In hormone unmanageable prostate growth docetaxel enhances future and
general life quality. Docetaxel has a place with a class of chemotherapy medications called plant
alkaloids. Plant alkaloids are 7produced using plants. The vinca alkaloids are produced using the
periwinkle plant. The taxanes are produced using the bark of the Pacific Yew tree. Vinca alkaloids
and taxanes are otherwise called antimicrotubule operators. Treatment with docetaxel has the
particular result of expanding survival time in patients with certain sorts of tumor. Some clinical
trials show median survival times to be expanded by just three months,

Mir-193a-5p Essay
In this article, we aimed to research the diagnostic value of peripheral blood and tissue miR–193a–
5p. And we also tend to illuminate the underlying molecular modulatory mechanism of miR–193a–
5p in lung cancer. Hereby, we comprehensively retrieve the eligible microarrays and performed
meta–analysis to explore the clinical diagnostic significance. Then we adopted bioinformatics
analysis to lucubrate the potential molecular mechanism. We collected predicted and validated target
genes of miR–193a–5p and further acquired the overlapping genes. GO, KEGG and PPI network
analysis were further performed for the overlapping genes. We hope what we obtained might offer
references for future researches.
Up to now, there is no study illuminating the ... Show more content on Helpwriting.net ...
Therefore, it is worthy to notice such special expression difference of miR–193a–5p in lung cancer.
The reasons causing such inverse peripheral blood and tissue miR–193a–5p expression remain
unclear yet. It still needs additional larger samples studies to validate and provide exact explanation.
Still, peripheral blood and tissue miR–193a–5p could provide a certain reference value for clinical
lung cancer diagnosis.
Since miR–193a–5p exerts its regulative functions through specifically targeting certain target
genes, we here collected the possible targets of miR–193a–5p and further uncover the underlying
regulatory pathways. We found that the top enriched items in BP, CC and MF were regulation of
neuron apoptosis; organelle outer membrane and tubulin–tyrosine ligase activity, respectively.
Mitochondria is the basic and important organelle in most of the eukaryocyte. Mitochondria outer
membrane permeabilization has been reported to be involved in cancer and be a promising
therapeutic target. [26–27] Thereby, miR–193a–5p might be also involved in lung cancer through
similar approach. Recently, Tubulin tyrosine ligase widespread loss has been found during the tumor
growth, which suggests tubulin tyrosine ligase activity may be involved in the regulation of tumor
cells [28]. As a result, tubulin tyrosine ligase activity might be related miR–193a–5p, which might
exert effects in lung cancer. Nevertheless, more studies are needed in the future. In KEGG

The Labeling Of Genetically Engineered Crops
Introduction: In an immense variation of ways, farmers grow their crops and keep them healthy and
ready for distribution. The need for a greater variety of healthy and resistant crop is consistently
rising as populations continue to increase around the world. Yet, agricultural food scientists have
manipulated the DNA structure of countless foods. One main concern for consumers is the use of
GMOs, genetically engineered crops. However, GMOs are very hard to find when manufacturers
claim to not have them in their products and also not completely healthy. To provide information to
customers, labeling requirements have been set up in many countries to aid international trade. In
this experiment we will test different foods to find traces of GMO including one that claims to not
contain GMOs. We hypothesize that the lettuce sample would not contain any GMO genes.
Material and Methods:
DNA extraction of samples for PCR.
Three samples were prepared: Soy bean with GMO, Soy bean without GMO, Lettuce, and Chex®
cereal. The food samples were crushed into a powder and separated. Next, 100 µl of Edwards buffer
was added to samples. For another minute, the food was then grounded. Then, 900 µl of Edwards's
buffer was then added to each sample and vortex. The samples were then boiled for 5 minutes and
centrifuged for 2 minutes. Next 350 µ of each supernatant was transferred to fresh tubes. 400 µl of
isopropanol was then added to the supernatant samples. The solutions were then inversed

The Effect Of N-3deficient Diet And Its Affect On Humans
Over the last century, the diet of the average human has been getting substantially worse. Vitamin
and mineral intake has drastically declined due to pesticides destroying the soil's natural nutrients,
which in turn created a yearn to understand this new diet's impact on the health of society
(Ettinger,2016). One major shift has been to a high ratio of omega–6 (n–6) polyunsaturated fatty
acids (PUFAs) to omega–3 (n–3) PUFAs, which a recent study attempts to examine in order to
understand this ratio's affect on humans (Sakayori et al., 2015). The experiment focuses on trying to
understand how an n–6excess/n–3deficient diet in a mother affects their offspring. In the
experiment, the wild–type (WT) mice were split up into two groups: control and experimental. In
the control group, the mice were fed a healthy ratio of n–6 PUFAs to n–3 PUFAs, while the
experimental group was fed a n–6excess/n–3deficient diet that is similar to the majority of current
human diets. These mice were fed their respective diet before pregnancy, as well as during
pregnancy, and the fatty acid content of the ... Show more content on Helpwriting.net ...
Compared to the control group, the experimental group's offspring had an increase in n–6 PUFAs,
and decrease in n–3 PUFAs in their brains, which means that the n–6 PUFA and n–3 PUFA

Symptoms And Treatment Of Cancer
Docetaxel also sold as Taxotere or Docecad, is a settled threatening to mitotic chemotherapy
with other chemotherapeutic pharmaceuticals as shown depending upon specific tumor sort and
stage.
Chemotherapy refers to the use of medicines or drugs to treat cancer. The capacity of chemotherapy
to murder cancer cells relies on upon its capacity to end cell division. For the most part, the
medications work by harming the RNA or DNA that advises the cell how to duplicate itself in
division. In the event that the cells can 't partition, they eventually die. The faster the cells are
partitioning, the more probable it is that chemotherapy will murder the cells, creating the tumor to
contract. The utilization of medications (whether chemotherapy, hormonal treatment or focused on
treatment) constitutes systemic treatment or tumor in that they are brought into the circulatory
system and are along these lines on

A Brief Note On Biotechnology And Biotechnological...
Biotechnology & Biotechnological Equipment Publication details, including instructions for authors
and subscription information: http://www.tandfonline.com/loi/tbeq20 Altered Gene Expression:
Induction/Suppression in Leek Elicited by Iris Yellow Spot Virus Infection (IYSV) Egyptian Isolate
Elsayed Elsayed Hafeza, Ahmed A. Abdelkhaleka, Abeer Salah El–Deen Abd El–Wahabb & Fatma
Hassan GalalcResults and Discussion Biological transmission and symptoms appearance IYSV was
first reported on leek seed crops in 2006 in the Willamette Valley (36). This virus is known to infect
other Allium spp., including onion and garlic (36). It has been reported that IYSV is transmitted by
the onion thrips (Thrips tabaci) but has not been shown to be transmitted by other thrips species
(20). The results from our study revealed that viral symptoms appeared in the biologically
inoculated plants (using Thrips tabaci) 10 days post inoculation. The inoculated leek plants showed
spindle–shaped, straw–colored, irregular lesions with occasional green islands. The severity of the
symptoms increased with the incubation time (data not shown). On the other hand, after mechanical
inoculation, no symptoms were observed on the inoculated plants. Widana Gamage (48) worked on
IYSV on leek (Allium porrum) in Sri Lanka and reported that straw–colored spots (2 mm to 3 mm
in diameter), surrounded by a greenish halo and a necrotic area were observed on the plant leaves.
Detection of IYSV IYSV was detected using ELISA

Mandatory Synthesis Report
Wnt3 plays an important role in the regulation of the adult hippocampus neurogenesis through
activation of the canonical Wnt pathway. We found BPA decreased the Wnt3 expression and protein
levels, leading to altered neurogenesis by BPA. We therefore investigated the specific involvement
of the Wnt/β–catenin that altered due to exposure of BPA and reduced neurogenesis. NSCs culture
were knockdown by Wnt3a siRNA followed by presence and absence of BPA treatment. We found
that number of β–tubulin+ cells decreased in Wnt3a siRNA knockdown group and BPA treatment
further reduced the number of β–tubulin+ cells (Figure 10A–B). NSCs differentiation was assessed
by β–tubulin+ cells. Next, immunoblot analysis revealed that Wnt3a knockdown and BPA treatment
to NSCs caused significantly down regulation of p–GSK–3αβ/GSK–3αβ ratio and thus caused
enhanced ratio of p–β–catenin/β–catenin and thus Wnt pathway down regulated (Figure 10C–D). ...
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Immunoblot analysis showed that GSK–3β knockdown caused significantly enhanced the level of
β–catenin that activate the Wnt pathway, while BPA treatment decreased the level of β–catenin that
enhanced due to GSK–3β knockdown group (Figure 10G–H). Furthermore, the level of downstream
target genes of Wnt/β–catenin pathway such as cyclinD1 and survivin after GSK–3β knockdown
enhanced but BPA treatment caused decreased their levels that enhanced due to GSK–3β
knockdown (Figure

Essay on Mercury: A toxic poison
Mercury: A toxic poison
No other metal better illustrates the diversity of effects caused by different chemical species than
does mercury. On the basis of chemical speciation, there are three forms of mercury: elemental,
inorganic, and organic compounds.
The major source of mercury is the natural degassing of the earth's crust, including land areas,
rivers, and the ocean, and this source is estimated to produce on the order of 2700 to 6000 tons per
year. The total man made release into the atmosphere is about 2000 to 3000 tons, and it is difficult to
assess what quantities of mercury come from human activities and what quantities from natural
resources. Run–off into natural bodies of water may contain mercury ... Show more content on
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Metallic mercury may be oxidized to inorganic divalent mercury, particularly in the presence of
organic material such as in the aquatic environment. Divalent inorganic mercury may, in turn be
reduced to metallic mercury when conditions are appropriate for reducing reactions to occur. A
potential source of alkyaltion of divalent mercury is methylation to dimethyl mercury by anaerobic
bacteria. Methyl mercury is of major toxicology significance. If it is taken up into the food chain by
fish, it may eventually cycle through humans or it may diffuse into the atmosphere and return to the
earth's crust or to bodies of water as methyl mercury in rainfall1.
The Japanese Tragedy
The steadily mounting environmental contamination by mercury was ignored until a tragic series of
events occurred in Japan. In the beginning many cats were seen to dance in the small fishing villages
along Minamata Bay on Kyushu Island. They clearly were mad, because they screamed incessantly
and often ended their dance and their lives by flinging themselves into the sea. This activity was first
observed in 1953, and by 1960 the nervous tremors that preceded the dance were familiar not only
in cats, but also in birds, fish, pigs, and dogs. A greater terror was aroused as human beings were
also stricken, often several members of one family. Fearing that they might have a shameful
infectious disease, the poor fisherman kept their tragedy to themselves for 3

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

Lissencephay Research Paper
Human brain development represents a dynamic and complex process that requires fine tuning of
biochemical, genetic, environmental and physical events. Neuronal migration is a significant part of
neurodevelopment, which is a term that describes moving of nerve cells from their origin to their
ultimate location.
During the first trimester of pregnancy, abnormalities of the migrating neuroblasts and glioblasts
may result in abnormal gyral development, leading to a disorder known as lissencephaly.
Lissencephaly (a term derived from Greek words for "smooth brain") is characterized by a smooth
cortical surface, and occurs because there is a disruption of the ordered migration of neurons to their
permanent place in the brain cortex.
Genes and molecular pathophysiology
Lissencephaly was initially described in 1868 as a distinct clinical entity by Owen, and it was also
the first of the human cortical malformations for ... Show more content on Helpwriting.net ...
Central, cingulate, calcarine and parieto–occipital sulci are visible at 27 weeks of gestation, while
secondary and tertiary gyrations arise late in gestation.
In lissencephaly, the cerebral hemispheres resemble the smooth 20–week fetal cerebral cortex, with
the absence of secondary sulci. Gray matter heterotopia (i.e. mislocation of the gray matter),
macrogyria, polymicrogyria and schizencephaly (together with defective cortical lamination) often
accompany this condition.
Pachygyria represents similar disorder with less severe pathology than in lissencephaly, as areas of
normal laminar organization can be seen. However, these two conditions are not mutually exclusive
and can occur together in the same brain, thus they are considered as different degrees of the same
fundamental disorder in cell migration and cortical

Cell Structures And Transporters Unit Assessment
Cell Structures and Transporters Unit Assessment
Cancer is one of the most dangerous and fatal diseases, which is caused by uncontrolled growth and
proliferation of cells. Cancer cells' survival, progression and metastasis are tightly associated with
the cellular components. For example, when cells metastasizing, they use cell protrusion which
provided by the actin cytoskeleton to penetrate the extracellular matrix, they also secrete
plasminogen activator to increase protease plasmin's activity in order to penetrate the membrane.
Then some of the tumor cells transfer to other tissue and form metastatic tumor. The specific
functions of several cell structures and transporters in tumor cells are discussed as follows.
Lysosome plays important role in cells' behavior, it not only the degradation and recycle place for
cells, but it also associated with cellular processes such as autophagy and signaling. Especially in
cancer cells, the lysosomes are greater in number, larger, more active than normal cells. [1] The
mechanism for lysosome in cancer cells is that lysosome can release certain cathepsins, which is a
kind of virtual acidic hydrolases released from tumor cells into the extracellular space, which lead to
cancer cells' progression and death by apoptosis and apoptosis–like pathways. [2] On the one hand,
the cathepsins contribute to the degradation of intracellular substrates, regulation and recycle of
extracellular substrates. On the other hand, the cathepsins control

Chlamydomona Reinhardtii Essay
Chlamydomonas reinhardtii is a single–celled alga species that appears very small and green, and
each cell has two extracellular flagella composed of microtubules. (Guanglin et al., 2007). Cells,
such as C. reinhardtii, rely on movement for survival because they require the ability to regulate
their surroundings. C. reinhardtii are great model organisms for studying microtubules. The flagellar
microtubules of these unicellular organisms can be effortlessly examined due to the fast growth
rates, the ability to view flagella under a microscope, the ability to deflagellate cell bodies, and the
ability to introduce mutations to assign functions to specific proteins (Fernandez et al., 2007). C.
reinhardtii are also effective in assessing which proteins are responsible for the eyespot's sensitivity
to light by observing phototactic responses in various mutant strains. Phototaxis refers to the
movement of a cell body in response to light. Positive phototaxis occurs when the organism moves
toward the light, whereas negative phototaxis refers to when the organism moves away from the
light (Greiner et al., 2012). Since humans and many other species have shared conserved sequences
essential to the proper flagellar function and structure, the information ... Show more content on
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The microtubule ultimately forms when the GTP bound to the β–tubulin is hydrolyzed (Agard et al.,
2008). Microtubules possess the property of dynamic instability, which refers to extended periods of
shortening that result in a period of growth. Dynamic instability also refers to the opposite situation
involving a span of extended growth, followed by a period of shortening. This shortening period is
commonly known as catastrophe (Cassimeris et al., 2005). Dynamic instability is essential to cell
movement, cell signaling, and mitotic chromosome separation (Cabral et al.,

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

Treatment Of Chemotherapy With Cell Division
Docetaxel (XT) sold as Taxotere or Docecad, is a settled threatening to mitotic chemotherapy
with other chemotherapeutic pharmaceuticals as shown depending upon ... Show more content on
Helpwriting.net ...
Systemic treatment is regularly utilized as a part of conjunction with different modalities that
constitute "nearby treatment" (i.e. medications whose adequacy is limited to the anatomic territory
where they are connected) for growth, for example, radiation treatment, surgery, and/or
hyperthermia treatment. The adequacy of chemotherapy relies on upon the sort of tumor and the
stage. The general viability ranges from being corrective for a few growths, for example, some
leukemias, to being inadequate, for example, in some mind tumors,to being unnecessary in others,
as most non–melanoma skin cancers. Clinical information has indicated docetaxel to have cytotoxic
movement against bosom, colorectal, lung, ovarian, prostate, liver, renal, gastric, head and neck
tumors, and melanoma. In hormone unmanageable prostate growth docetaxel enhances future and
general life quality. Docetaxel has a place with a class of chemotherapy medications called plant
alkaloids. Plant alkaloids are 5produced using plants. The vinca alkaloids are produced using the
periwinkle plant. The taxanes are produced using the bark of the Pacific Yew tree. Vinca alkaloids
and taxanes are otherwise called antimicrotubule operators. Treatment with docetaxel has the
particular result of expanding survival time in patients with certain sorts of tumor. Some clinical
trials show median survival times to be expanded by just three months,

The Effects Of Hormone Therapies On Human Body And Will...
Traditionally men are expected to be the stronger sex, the breadwinner, the hunter– gatherer, but
when it comes to prostate cancer men can feel powerless. Hormone therapies are used to chemically
castrate men as a means of treating the cancer through more personalised medicine. However, when
the cancer becomes refractory, Docetaxel is used as a first line chemotherapy to treat metastatic
castration resistant prostate cancer in combination with Prednisolone. Mr. Smith (pseudonym) was
diagnosed with Advanced Metastatic Prostate Cancer which was controlled by Abiraterone Acetate
(an androgen biosynthesis inhibitor and works by inhibiting the CYP17 enzyme that is used to feed
the cancer) until the cancer started to progress, and was ... Show more content on Helpwriting.net ...
Cytotoxic chemotherapy was first discovered during World War II by Gilman and Philips when they
perceived the effect that nitrogen gas (used during WWI) had on the number of human cells
proliferating and recognised this as a potential treatment for cancer. From this discovery, biotherapy
was born helping to increase our knowledge in how to achieve cell death and tumour control
through use of cytokines and monoclonal antibodies (Young et al, 2006). Cancer is often described
as unregulated cell growth through a multistep process (Brighton et al, 2005). Brighton (2005)
describes the 'Hallmarks' of the cancer cell as needing to acquire these six steps in order to develop:
'self–sufficiency in growth signals, insensitivity to antigrowth signal, avoiding apoptosis, limitless
replicative potential, angiogenesis and tumour invasion/ metastasis'. These six Hallmarks of Cancer
describe the pathogenesis that a cell undertakes until it develops into a tumour which can then
potentially become malignant (Hanahan et al, 2011). While normal cells can control their own
proliferation that allows a homeostasis amongst cells, that new cells are born once the old cells have
died ensuring that there are enough cells available to fulfil the task at hand. Cancer cells are more
neurotic, they interrupt the normal signalling pathway within the healthy cells, and then they begin
to grow uncontrollably invading the

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 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
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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

Structural Differences Between Tubz And The Rest Of The...
Sofia Paz BIO 206 Writing Assignment #3
Detailed Focus Question: What role do the structural changes in GTPase domains between TubZ
and the rest of the Tubulin family play in the function of TubZ in plasmids and bacteriophages?
Introduction – Before examining the structural differences between TubZ and the rest of the Tubulin
family, it will be necessary to give background on both. Specifically, what Tubulin is and the
common characteristics of the Tubulin family, Tubulin's role in the cell, what TubZ is, what it's role
is, and what similarities it shares with other members of the Tubulin family. A general layout of the
paper will also be given at the end of this introduction. General layout would briefly describe the
order of the sections to follow.
Tubulin
"What is it?" – Tubulin is a family of proteins which belong in to a bigger family known as globular
proteins. "Globular protein" refers to a particular class of protein characterized by its spherical–like
shape and water solubility. The Tubulin family contains proteins which make up microtubules.
"What is its function?" – Since Tubulin makes up microtubules they play a role in the structure of
eukaryotes and form the cytoskeleton. They also play a role in chromosomal separation in
mitosis/meiosis.
FtsZ is the prokaryotic homolog of Tubulin (eukaryotic protein). One reason it will be useful to
mention FtsZ is because, while the

Martin Chalfie's Research
On January 15, 1947 in Chicago Illinois, Martin Chalfie was born to parents Vivian and Eli Chalfie.
Martin and his two younger brothers lived a very normal and suburban lifestyle. In 1965 he enrolled
at Harvard University, his time there was largely unsatisfying and resulted in a loss of interest in
biological science. His passion would be reignited while teaching high school chemistry in
Connecticut. Martin was offered a summer research opportunity at Yale Medical School with Jośe
Zadunaisky. From this launching point he would further his career by studying under Bob Perlman,
discovering the usefulness of C. elegans at the LMB in Cambridge, England, obtaining a tenure at
Columbia University, and eventually conducting his experiments on the ... Show more content on
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This discovery belonged to Roger Tsien, who shared the 2008 Nobel Prize with Martin Chalfie.
Tsein speculated that by randomly mutating the DNA of the GFP protein, he could produce
functional proteins able to emit different different wavelengths of light. His speculation was correct
and resulted in a great assortment of mutant GFP proteins that fluoresced at different wavelengths
and allowed for the viewing of multiple protein targets in cells (Tsien p.

Genetically Modified Organisms For Food Sources Essay
Introduction: GMO, genetically modified organisms, are organisms that are used for food sources
and are manipulated by biotechnology, most often by gene transfer (Ahmed, 2002). Most
agricultural food sources such as fruits, vegetables, or any other mass–produced crops are known
examples of GMO (Owens, 2000). Many question the ethics or reasoning behind the production of
GMOs due to its interference with naturally bound events but biotechnological gene transfer is
vastly beneficial because it leads to: multiplication of crop yields, more affordable food sources,
food security, and resistance to pests and harmful diseases (Phillips, 2004). Benefits of GMO are
inevitable and are beneficial to almost everyone, but precautions are made to routinely regulate
GMOs due to possible health complications (Weiss, 2014).
Polymerase chain reaction (PCR) was the primary method used for this experiment to test for
genetically modified organisms by determining the presence of 35s, the GMO biomarker (Hardegger
et al., 1999). PCR amplifies specific segments of DNA, producing millions of copies of a specific
DNA sequence. PCR uses thermal cycling, which causes enzymatic replication of the selected DNA
sequence (Bartlett, 2003). The 35s promoter is used to amplify the sequence of DNA that is present
in GMO. This particular gene region is approximately 162 base pairs and the 35s promoter cannot
amplify any other sequence but the GMO specific sequence. This will make the 35S promoter the
key to

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

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