cell Flashcards
1
Q
The concept of the cell started with the
A
microscopic observations of Robert Hooke of a dead cork tissue in 1665
2
Q
the first person to observe
living and moving cells under a microscope
A
antoine van leeuwenhoek
3
Q
differentiate prokaryotic from eukaryotic cells
A
prokaryotic cells consist of a single compartment containing dna, rna, proteins, and small molecules encapsulated by a plasma membrane, enclosed by a cell wall. while eukaryotic cells have a nucleus containing dna and enclosed by plasma membrane. the cytoplasm contains many organelles enclosed by plasma membrane
4
Q
examples of prokaryotic cell
A
bacteria, blue green algae, pleuropneumonialike organisms
5
Q
examples of eukaryotic cellss
A
fungus, animal, plant cells
6
Q
this cell is about 1 um long and no nuclear envelope with circular dna in cytoplasm
A
prokaryotic
7
Q
this cell is 4um to many cm long, with nuclear envelope and true nucleus and a very long dna organized into chromosome
A
eukaryotic
8
Q
in eukaryotes, rna is synthesized and processed in ___
A
nucleus
9
Q
chromatin proteins found in eukaryote that compact and organize DNA into double helix, they also play a role in regulating gene expression
A
histones
10
Q
serve as a protective barrier and
regulates which materials can pass in or out
A
cell membrane
11
Q
The nucleus is separated from the cytoplasm by a
A
nuclear membrane
12
Q
the cytoplasm is separated from the surrounding fluids by a
A
cell membrabe
13
Q
he substances of the cel
A
protoplasm
14
Q
comprises 70 – 85% of cell mass, with the exception of adipocytes, and contains
dissolved molecules, suspended particulates, and membrane
A
water
15
Q
ions that are significant within the cell
A
Potassium, magnesium, phosphate, sulfate, bicarbonate
16
Q
ions that are less significant withn the cell
A
na, cl, ca
17
Q
compose 10 – 20% of the cell mass
A
proteins
18
Q
what are the structural proteins
A
filaments and microtubules (polymeric proteins)
19
Q
individual, soluble molecules that
catalyze actions required for cellular function
A
globular proteins
20
Q
the most significant lipid
A
phospholipids and cholesterol
21
Q
Form cell membranes and intracellular membrane barriers
A
lipids
22
Q
e the fat stored by adipocytes as an energy source
A
triglycerides
23
Q
s comprising 1 – 6% of cell mass, depending upon cell type
A
carbohydrates
24
Q
carbohydrate that is readily available in extracellular fluid
A
dissolved glucose
25
, a glucose polymer is found intracellularly
glycogen
26
A selective membrane that encloses the cell . It is a thin, elastic structure approximately 7.5
– 10 nm thick.
cell membrane
27
General functions of plasma membranes
1. Selective permeability and transport
2. Synthesis and detoxification
3. Energy transduction
4. Conduction of electrical impulse
5. Insulation
6. Intracellular communication
7. Cell- to-cell adhesion and recognition
8. Compartmentalization of cell
9. Cell movement
10. Site of hormone and neurotransmitter receptors
28
composition of cell membrane
55% proteins
25% phospholipids
13% cholesterol
4% other lipids
3% carbohydrates
28
it makes the membrane more fluid
unsaturated fatty acid with double bonds
29
a portion of the lipid bilayer that is pointed inwards and made up of fattu acids
hydrophobic tail
29
it makes the membrane lipid less fluid
saturated fatty acid without double bonds
30
a portion of the lipid bilayer adjacent t the extracellular and intracellular water and made up of phosphates
hydrophilic head
30
properties of membrane lipids
undergoes lateral diffusion
capable of transverse motion
asymmetry in distribution
passive permeability
30
This property of membrane lipids
is responsible for the fluidity of the membrane
undergoes lateral diffusion
31
Passive permeability and degree of fluidity is
influenced by
the type of fatty acid associated with the membrane lipid
32
may also reduce membrane fluidity and
permeability, and increase membrane rigidity and strength
cholesterol dissolved in lipid bilayer
32
it constitutes a barrier against movement of water molecules and water-soluble substances between the extracellular and intracellular fluid compartments.
lipid bilayer
33
he cell membrane contains many globular proteins many of which are
glycoproteins
34
responsible for most of the functional behavior of the cell membrane which include
permeability and transport of substances, intracellular communication and some antigenic
characteristics of the cell.
membrane proteins
35
These proteins are embedded in the lipids and some cross the
entire membrane
intrinsic or integral membrane
36
-these act like gates that allow substances
to go into/out of cell
intrinsic or integral membrane
37
Proteins that
are found along the edge of the membrane (inside
or outside);
extrinsic or peripheral proteins
38
-these serve as receptors for hormones;
entire complex moves into cell
extrinsic or peripheral proteins
39
Unique property of membrane proteins
the membrane proteins undergo lateral movement (10-9 to 10-11 cm2/sec)
40
occur in combination with proteins or lipids, in the form of
glycoproteins or glycolipids .
membrane carbohydrates
41
Most of the integral proteins that we mentioned are
glycoproteins
42
what are the carbihydrates present in cell membrane
glycoproteins, glycolipids, proteoglycan
43
The entire surface of the cell has a loose carbohydrate coat called
glycocalyx
44
Provides the cell a net negative charge that repels other negatively charged
objects, including other cells, at moderate distances
glycocalyx
45
-it is also “sticky” allowing close contact (attachment) between cells
glycocalyx
46
Acts as receptors substances for hormones
glycocalyx
47
Augment immune responses
glycocalyx
48
provides the fluid medium necessary for biochemical reactions to take place
inside the cell.
cytosol
48
All the substances in between the cell organelles of a cell is called the
cytosol
49
Everything in a cell including the cytosol and organelles except the nucleus is called
cyroplasm
50
e a specialized subunit within a cell that has a specific
function.
organelles
51
membrane bound organelles
1. Nucleus
2. Endoplasmic Reticulum
3. Lysosomes
4. Peroxisomes
5. Secretory Vesicles
6. Mitochondria
52
nonmembrane bound organelles
ribosomes
microtubules
microfilaments
intermediate filaments
53
s the control center of the cell because it stores all of the genetic instructions for
manufacturing proteins
nucleus
54
spans the nuclear
envelope. These are tiny passageway
for the passage of proteins, RNA, and
solutes between the nucleus and the
cytoplasm.
nuclear pores
55
fine fibrils about 100 A thick,
composed of DNA (genetic material) and proteins
(histones and acid proteins
chromatin
56
what is the estimated genes distributed in 46 chromosomes
22000
57
Chromatins that are less dense during interphase and are genetically active
euchromatin
58
Chromatin that remains condensed during interphase and non- replicating
heterochromatin
59
Newly made ribosomal
subunits exit the cell’s nucleus through the
nuclear pore
60
a dense body rich in RNA and protein. It is responsible for
manufacturing the RNA necessary for construction of ribosomes.
nucleolus
61
Newly made ribosomal
subunits exit the cell’s nucleus through the
endoplasmic reticulum
62
flat sacs or cisternae with
the presence of ribosomes
attached to the surface of the
membrane
pough er
62
It is also called the highway of the cell
for transporting, synthesizing, and storing materials
er
63
function of rer
transport of exporatble proteins
64
The SER occurs in the form of
membranous tubules withour ribosomes
65
functions od ser
* Synthesis of phospholipids and steroids
* Intracellular transport
* Impulse transmission
* Oxidation of fatty acids
* Detoxification of xenobiotics
66
3 layers of golgi apparatus
transport vesicle
saccules
secretory granules
67
small spherical
structures that are thought to arise from the ER
transport vesicle
68
large flattened structures that are
continuous with tubular elements
saccules
69
large spherical vesicles
containing transported substances.
secretory granules
70
component of secretory granules that determines the specific destinations of the vesicle in the cell
protein coatings
71
This side of golgi apparatus is nearest to the nucleus and it is where transport vesicles
are formed from the ER.
forming PHASE (cis)
72
This side of golgi apparatus is located near the plasma membrane where
secretory granules are formed ,migrates to the cell surface and fuses to the cell membrane
and content is exocytosed
maturing phase (trans face)
73
functions of golgi
Stores, modifies and packages and transport proteins
2. Synthesis of polysaccharides eg. Hyaluronic acid and chondroitin sulfate
3. Glycosylation of proteins
74
vesicular organelles that form by breaking off from the Golgi apparatus
and then dispersing throughout the cytoplasm.
lysosome
75
t is a small organelle about 0.2-0.4 um .
lysosome
76
components of lysosome
variety of acid hydrolses and some 40 enzymes
77
function of lysosome
autophagy-a process wherein a cell digest its own structure
78
small (0.15 to0.5 um) structures that arise from the ER
peroxisomes
79
difference of lyso and peroxisomes
peroxisomes are derived form the smooth er and contains oxidases (rather than hydrolases)
80
the 3 oxidative enzymes of peroxisome which serve to transfer hydrogen atoms from various molecules to oxygen producing hydrogen peroxide
d. amino acids oxidase
urate oxidase
catalase
81
It is the major site of oxygen utilization of cells
just like the mitochondria.
peroxisome
82
utilizes H202, a by pdt of metabolism to oxidize some substrate like phenol, formic acid, formaldehyde and alcohol via peroxidase reaction or convert H2O2 to H2O
catalase
83
Metabolism product (peroxidation reaction)
RH2+ O2>R+ H2O2 >H2O2 + RH2>R’ + 2H2O
84
. Examples of ROS
hydroxyl radical OH, H2O2, and superoxide (O2−O2−).
85
Some ROS are important for certain cellular
functions, such as
cell signaling processes and immune responses against foreign substances
86
why are free radicals reactive
because they contain free unpaired electrons
87
, oversee reactions that neutralize free radicals.
peroxisomes
88
s a membranous, bean-shaped organelle that is often called the “Power house” of the cell. Without them, cells will be unable to extract energy from the nutrients, and all cellular functions would stop.
mitochondria
89
The inner membrane of mitochondria is highly folded into structures called
cristae
90
site of protein synthesis
ribosomes
91
s composed of a complex thread-like network found throughout the cell consisting of three different kinds of protein-based filament
cytoskeleton
92
function of cytoskeleton
1. provide shape and structural support for cell
2. important in cell motility;
3. cell reproduction (mitosis);and
4. transportation of substances within the cell.
93
the widest component of the cytoskeleton at 25 um in diameter. It appears as
a hollow tube.
microtubules
94
One microtubule is composed of
13 columns of protofibrils
95
each column of protofibrils is made up of
polymerized dimers of α-tubulin and β-tubulin, two globular proteins that occur as dimer
96
Factors that prevent polymerization of microtubules are
low temp, calcium, anticancer drugs
97
anticancer drugcs that act by preventing polymerization
vincristine ,vinblastine and colchicine
98
Factors that promote polymerization:
warmth, gtp (guanosine triphosphate), cAMP and magnesium ion and MAP (microtubule associated protein)
99
100
function of microtibules
structural support
morphogenesis
cell motility
transport of macromolecules
101
structures composed of microtibules
cilia
flagella
102
main parts of cilia and flagella
basal body
terminal plate
axoneme
103
this lart kf the microtubules is located within the cell
basal body
104
basal body is composed of
9 peripheral fibers
105
separates axoneme from basal body
terminal plate
106
the arms of sub fiber a of peripheral doublet contains what protein
dynein which has atpase activity
107
a rare autosomal recessive genetic ciliary disorder comprising the triad of situs inversus, chronic sinusitis, and bronchiectasis
kartgener's syndrome
108
kartgener's syndrome results from
mutation involving dynein arms
109
the cellular origin point for microtubules extending outward as cilia or flagella
centrioles
110
how do microtubules grow out from centrioles
by adding more tubulin subunits
111
microfilaments is composed kf
actin and myosin
112
g form and f form of actin
g-globular
f-polymerized
113
functions of microfilaments
responsible for active motile function of cytoskeleton
provides rigidity and shape to cell
provision of microtrabecular lattic
114
they can depolymerize and reform quickly, enabling a cell to chailnge its shape and move
microfilaments
115
the movement of an entire cell in relation to its surroundings
amoeboid movement
116
bundles of microfilaments in the cytosol that permits rapid diffusion of fluids and dissolved substances throughout the cell
microtrabecular lattice
117
long, ropelike fibrous sub units of polypeptide in chains
intermediate filaments
118
what do you call intermediate filaments in epithelial tissues
tonofibrils
119
they resist tensions and are not affected by colchicine kr cytochalasine
intermediate filaments
120
most stable component of cytoskeleton
intermediate filaments
121
functions kf intermediate filaments
maintains epitheloid shape
anchor cell organelles together within the cell
links cell to cell by forming cell to cell junctions
122
functions kf intermediate filaments
maintains epitheloid shape
anchor cell organelles together within the cell
links cell to cell by forming cell to cell junctions
