Anatomy, physiology

2.  -All organisms are cellular in nature ,be they
one celled “generalists” like amoebiasis or
complex multicellular organisms such as
humans, dogs, or trees.
 -Just as bricks and timbers are the structural
units of a house , cells are structural units of
all living things.

3.  -Since 1980s cell research has been done and our
present understanding of the cell provides us with
four concepts collectively known as cell theory:
 .A cell is the basic structural and functional unit of
living organisms ; when you define the properties of a
cell , you are infact defining the properties of life.
 .The activities of organism is dependent on both the
individual and collective activities of its cells.
 .According to the principle of complimentarity, the
biochemical activities of cell are determined by and
made possible by the specific subcellular structures
of cells.
 .The continuity of life has a cellular basis.

4.  Def. The minimum amount of matter that is
alive and as such is the fundamental unit
from which the biological hierachy is
fashioned and on which life processes
depend
 -It’s a microscopic package that contains all
the parts necessary to survive , in an ever
changing world.
 -Cells are diverse in both size and shape.

5.  Cell diameter ranges from 2 micrometers in
smallest cells to 10 centimeters or more in
the largest cell.
 As for length , range from a few micrometers
to a meter or more.
 Shape also varies in cells , some are
spherical(fat cells), some are disc shaped(red
blood cells), some are branching (nerve cells),
and some cube like(kidney tubule cells).

6.  Cell majorly has three parts:
-Nucleus
-Cytoplasm(with cytoplasmic organelles)
-Plasma membrane

7.  Two different kinds of genetic material exist:
deoxyribonucleic acid (DNA) and ribonucleic
acid (RNA).
 Most organisms use DNA for their long-term
information storage, but some viruses (e.g.,
retroviruses) have RNA as their genetic
material.
 The biological information contained in an
organism is encoded in its DNA or RNA
sequence

8.  There are two types of cells:
.eukaryotic
.prokaryotic.
 Prokaryotic cells are usually independent,
while eukaryotic cells are often found in
multicellular organisms.

9. Prokaryotes Eukaryotes
Typical organisms bacteria, archaea
protists, fungi, plants,
animals
Typical size ~ 1–10 µm
~ 10–100 µm (sperm
cells, apart from the
tail, are smaller)
Type of nucleus
nucleoid region; no
real nucleus
real nucleus with
double membrane
DNA circular (usually)
linear molecules
(chromosomes) with
histone proteins
RNA-/protein-synthesis coupled in cytoplasm
RNA-synthesis inside
the nucleus
protein synthesis in
cytoplasm
Cytoplasmatic structure very few structures
highly structured by
endomembranes and a
cytoskeleton
Cell movement
flagella made of
flagellin
flagella and cilia
containing
microtubules;
lamellipodia and
filopodia containing
actin
Mitochondria none
one to several
thousand (though
some lack
mitochondria)
Chloroplasts none in algae and plants
Organization usually single cells
single cells, colonies,
higher multicellular
organisms with
specialized cells
Cell division
Binary fission (simple
division)
Mitosis (fission or
budding)
Meiosis

10.  The prokaryote cell is simpler, and therefore
smaller, than a eukaryote cell, lacking a
nucleus and most of the other organelles of
eukaryotes. There are two kinds of
prokaryotes: bacteria and archaea; these
share a similar structure.
 Nuclear material of prokaryotic cell consist of
a single chromosome that is in direct contact
with cytoplasm. Here, the undefined nuclear
region in the cytoplasm is called nucleoid.

11.  A prokaryotic cell has three architectural regions:
1.On the outside, flagella and pili- project from the
cell's surface.
- These are structures (not present in all prokaryotes) made
of proteins that facilitate movement and communication
between cells;
2.Enclosing the cell is the cell envelope – generally
consisting of a cell wall covering a plasma membrane
though some bacteria also have a further covering layer
called a capsule.
-The envelope gives rigidity to the cell and separates the
interior of the cell from its environment, serving as a
protective filter

12. 3.Inside the cell is the cytoplasmic region that
contains the cell genome (DNA) and ribosomes
and various sorts of inclusions.
- A prokaryotic chromosome is usually a
circular molecule (an exception is that of the
bacterium Borrelia burgdorferi

13.  Plants, animals, fungi, slime moulds, protozoa, & algae are
all Eukaryotic.
 These cells are about 15 times wider than a typical
prokaryote and can be as much as 1000 times greater in
volume.
 The major difference between prokaryotes and eukaryotes
is that eukaryotic cells contain membrane-bound
compartments in which specific metabolic activities take
place.
 Most important among these is a cell nucleus, a
membrane-delineated compartment that houses the
eukaryotic cell's DNA. This nucleus gives the eukaryote its
name, which means "true nucleus:
 The plasma membrane resembles that of prokaryotes in
function, with minor differences in the setup. Cell walls
may or may not be present.

14.  The eukaryotic DNA is organized in one or
more linear molecules, called chromosomes,
which are associated with histone proteins
 . All chromosomal DNA is stored in the cell
nucleus, separated from the cytoplasm by a
membrane.
 Some eukaryotic organelles such as
mitochondria also contain some DNA.

15.  Many eukaryotic cells are ciliated with primary
cilia.
 Primary cilia play important roles in
chemosensation, mechanosensation, and
thermosensation.
 Cilia may thus be "viewed as sensory cellular
antennae that coordinate a large number of
cellular signaling pathways, sometimes coupling
the signaling to ciliary motility or alternatively to
cell division and differentiation."[7]
 Eukaryotes can move using motile cilia or
flagella. The flagella are more complex than
those of prokaryotes.

17.  Consist
 .Nuclear membrane.
 .Nucleoli
 .Chromatin

19.  -It’s the cellular material inside the plasma
membrane and outside the nucleus.
 -Is the major functional area, the site where
most cellular activities are accomplished.
 -Consists of 3 major elements
.Cytosol
.Organelles
.Inclusions

20.  -The viscous , semi transparent fluid
substance of the cytoplasm within which the
other elements are suspended.
 -Dissolved in the cytosol which, is largely
water are soluble proteins, salts, sugars, and
a variety of other solutes.

21.  Are the metabolic machinery of the cell.
 Each type of organelles is engineered to carry
out a specific function for the cell as a whole ,
some synthesize proteins, others package
those proteins and so on.

22.  Not functioning units , but instead are chemical
substances that may or may not be present
depending on the specific cell type eg. Of
inclusions are stored nutrients , such as glycogen
granules abundant in liver and muscle cells and
lipid droplets common in fat cells , pigment(
melanin ) granules seen in certain cells of the
skin and hairs and zymogen (enzyme containing)
granules synthesized in pancreatic cells and then
transported.
 -Other secretory products (mucus), water
vacuoles and crystals of various types are also
inclusions.

23.  Are specialized cellular compartments each
performing its own job to maintain the life of the
cell.
 Most organelles are bounded by a selectively
permeable membrane similar in comparison to
the plasma membrane , which enables them to
maintain an internal environment quite different
from that of the surrounding cytosol.
 -This compartmentalization is crucial to the
functioning of the cell , without it , thousands of
enzymes would be randomly mixed and
biochemical activity would be chaotic.

24.  Include:
.Mitochondria
.Ribosomes
.Rough endoplasmic reticulum
.Smooth endoplasmic reticulum
.Lysosomes
.peroxisomes

25.  Microfilaments
 Inter mediate filaments
 Microtubules
 Centrioles
 Cilia
 flagellum

26.  Tiny thread like or sausage shaped organelles, but in living cells
they squirm, elongate and change shape almost continuously.
 Are power houses of the cell as provide most of the ATP supply.
.
 Mitochondria generate the cell's energy by oxidative
phosphorylation, using oxygen to release energy stored in
cellular nutrients (typically pertaining to glucose) to generate
ATP.
 Mitochondria multiply by splitting in two.
 Respiration occurs in the cell mitochondria.
 Density of mitochondria in a particular cell reflects that cells
energy requirements and mitochondria are generally clustered
where the action is busy cells like( muscle and liver) have
hundreds of mitochondria where as cells that are relatively
inactive (such as lymphocytes) have just a few.

27.  Each mitoch….. Surrounded by two lipid bilayer
membranes .
 Outer membrane is smooth and featureless but
inner membrane has shelf like inward folds called
cristae that protrude into the gel like substance
within the mitochondrion called the matrix.
 Mitoch…… contain DNA and RNA and are self
replicating organelles.
 When cellular requirement for ATP increase the
mitochondria simply pinch into half(fission) to
increase their number , then grow to their former
size.

28.  Is an extensive system of interconnected parallel
membranes that coils and twists through the
cytoplasm,enclosing fluid filled cavities .
 Have 2 types i.e RES and SER
 One variety or the other may dominate in a given cell
depending on the specific functions of the cell.
 RES has ribosomes on its surface and SER lacks them
 RES is particularly abundant in cells specialized to
make and release proteins that function at other
locations such as most secretory cells ,antibody
producing plasma cells and liver cells, which produce
most blood proteins.
 RES also synthesize phospholipids and cholesterol

29.  SER is a continuation of RES.
 Plays no role in protein synthesis instead its
enzymes catalyse reactions involved with
 a)lipid metabolism and synthesis of
cholestrol(in liver cells.)
 b)synthesis of steroid based hormones such
as sex hormones(testosterone synthesizing
cells of testes are full of SER)
 C)absorption, synthesis and transport of
fats(in intestinal cells)

30.  d)Detoxification of drugs(in liver and kidneys)
 e)Calcium storage and release during muscle
contraction(skeletal and cardiac muscle)

31.  Compose of proteins and one variety of RNA.
 Sites for protein synthesis .
 Some float freely in cytoplasm and make proteins
that will reside in cytosol for cellular use , where
as membrane bound (rough endoplasmic
reticulum) ribosomes are chiefly involved in the
synthesizing protein products designed for
cellular membranes or for export from the cell.
 -Ribosomes can switch back and forth between
these two functions attaching to and detaching
from the membranes of the endoplasmic
reticulum according to the type of protein they
are making at a given time.

32.  Appear as flattened membranous sacs,stacked
like dinner plates ,associated with swarms of tiny
membraneous vesicles.
 The primary function of the Golgi apparatus is to
modify, process and package the
macromolecules such as proteins and lipids that
are synthesized by the cell.
 GA also pinches off vesicles containing lipids and
trans membrane proteins destined for the plasma
membrane and packages digestive enzymes into
membranous sacs called lysosomes that remain
into the cell.]

33.  Spherical membranous bags containing
hydrolytic enzymes.
 Their enzymes are synthesized on the
ribosomes of RES and packaged by the Golgi
apparatus.
 Lysosomes contain digestive enzymes (acid
hydrolases). They digest excess or worn-out
organelles, food particles, and engulfed
viruses or bacteria.
 Lysosome function as cells demolition sites
for

34.  Membraneous sacs containing powerful oxidase
enzymes that use oxygen to detoxify a number
of harmful or toxic substances, including alcohol
and formaldehyde.
 Are numerous in liver and kidney cells which are
very active in detoxification.
 have enzymes that rid the cell of toxic peroxides.
 The cell could not house these destructive
enzymes if they were not contained in a
membrane-bound system.
 These organelles are often called a "suicide bag"
because of their ability to detonate and destroy
the cell.

35.  Is a network of protein structures called
microfilaments(cell motility or changes in cell
shape), microtubules(over all organizers of
cytoskeleton) and intermediate
filaments(internal wires resisting pulling
forces on the cell) .
 Act as cells bones and muscles hence
supporting intracellular structures and also
provide machinery to generate various cell
movements

36.  The centrosome produces the microtubules
of a cell
 It directs the transport through the ER and
the Golgi apparatus.
 Centrosomes are composed of two centrioles,
which separate during cell division and help
in the formation of the mitotic spindle

37.  Cilia are hair like motile cellular extensions that
occur typically in large numbers, on the free
surfaces of certain cells
 -Ciliary action is important in moving substances
in one direction across cell surfaces.
 Cilia propels other substances across a cell
surface
 Flagella is the product of substantially longer
projections formed by centrioles.
 Single example of flagellated cell in human body
is a sperm which has one propulsive flagellum
commonly called a tail.
 Flagellum propels the cell itself

38.  Vacuoles store food and waste. Some
vacuoles store extra water. They are often
described as liquid filled space and are
surrounded by a membrane. Some cells, most
notably Amoeba, have contractile vacuoles,
which can pump water out of the cell if there
is too much water.

39.  Most cells have only one nucleus , while others like
skeletal muscle cells ,bone destruction cells and liver
cells are multinucleated.
 All body cells are nucleated with exception of mature
red blood cells(their nuclei is ejected before they
enter the blood stream)
 These anucleate cells cant reproduce themselves
hence they live in blood stream for only 3-4months
before they begin to deteriorate.
 Nucleus diameter average 5nanometers and is the
largest organelle in the cell.
 Most often spherical or oval, its shape usually
conforms to the shape of the cell eg. If a cell is
elongated the nucleus may be extended as well.

40.  Nucleus has three distinct regions
 a) nuclear membrane
 b) nucleoli
 c)chromatin

41.  Also known as nuclear envelope
 Is double membrane barrier similar to
mitochondrial membrane.
 Between the two membranes is a fluid filled
space called the perinuclear cisterna.
 Outer nuclear membrane is continuous with the
ER of the cytoplasm and may be studded with
ribosomes.
 Nuclear membrane is selectively permeable but
passage of substances is much freer than
elsewhere because of its relatively larger pores.

42.  Dark staining spherical bodies found within
the nucleus.
 Made up of ribosomal RNA and proteins and
are not membrane bounded.
 Ideally have one or two per cell but may be
more
 They are ribosome producing machines

43. A system of bumpy threads weaving their way
through the nucleoplasm.
Composed of approximately equal amounts of
DNA which constitute our genetic material

44.  STRUCTURE
-Defines the extent of the cell and acts as a
fragile barrier.
-Also called cell membrane
-Its thin but stable structure composed chiefly of
a double layer , of bilayer of phospholipid
molecules with protein molecules dispersed in it
-The lipid bilayer form the basic fabric of the
membrane and is relatively impermeable to most
water soluble molecules
The proteins are responsible for most of
specialized functions of the plasma membrane.

45.  A)Microvilli-Minute ,finger like extensions of plasma
membrane that project from a free or exposed cell
surface.
 -Increase plasma membrane surface area
 Mostly found on absorptive cells such as kidneys
tubule and interstitial cells.
 B)Membrane junctions-though certain cell types are
footloose eg.blood cells, sperm cells and some
phagocytic cells many cells particularly those of
epithelial cells are knit into tight communities
 C)Tight junctions-prevent free passage of molecules
through the intercellular space between adjacent cells
and of an epithelium membrane .e.g.. In GIT they
keep digestive enzymes and micro organisms from
seeping into the blood stream

46.  D)Desmosomes-act as mechanical couplings
or adhesion junctions along the sides of
abutting cells to prevent their separation.
 -Abundant in cells subjected to great
mechanical stress such as skin, heart muscle
and neck of the uterus
 E)Gap junctions-Allows direct passage of
chemical substances between adjacent cells.
 -Found in embryonic cells and in adults in
electrically excitable tissues such as heart

47.  1.Functions of Plasma membrane
 2.a)Name the organelle that is the major site
for ATP synthesis.
 b)Name three organelles involved in protein
synthesis and or modification
 C)Name two organelles that contain enzymes
and describe their relative functions
 3.If a cell looses or ejects its nucleus what is
the fate and why?