cell physiology Flashcards
histology (162 cards)
1
Q
what are 2 major components of cell’s interior
A
- nucleus
- cytoplasm
2
Q
where is the nucleus usually
A
centre
3
Q
what is nucleus surrounded by
A
double membrane
4
Q
what separates nucleus from rest of the cell
A
nuclear envelope
5
Q
what is the nuclear envelope pierced by
A
nuclear pores
6
Q
what does nucleus contain
A
DNA
7
Q
what are the types of RNA
A
- mRNA
- tNRA
- rRNA
8
Q
what does mRNA do
A
deliver coded messages to ribosomes
9
Q
what is rRNA
A
essential component of ribosomes
10
Q
what is tRNA
A
transfer delivers appropriate amino acids
11
Q
examples of organelles
A
- endoplasmic reticulum
- golgi complex
- lysosomes
- peroxisomes
- mitochondria
12
Q
are organelles required for survival
A
yes
13
Q
what does cytoskeleton do
A
gives cell its shape
14
Q
what tis cytosol
A
cell ‘liquid’
15
Q
what occurs in cytosol
A
many chemical reactions
16
Q
what are the types of endoplasmic reticulum
A
- rough
- smooth
17
Q
why is the RER rough
A
studded with ribosomes
18
Q
what happens in ribosomes
A
protein synthesis
19
Q
what is different in appearance between rough and smooth ER
A
rough is flat like sacs whereas smooth is round tubules
20
Q
what happens in RER
A
protein synthesis
21
Q
what happens after proteins made in RER
A
SER packages the secretory product into transport vesicles which bud off and move to the golgi complex
22
Q
what happens to transportt vesicle from the SER
A
transport vesicle fuse with the golgi complex, open up and empty their contents into the closest golgi sac
23
Q
is the SER involved in protein synthesis
A
no doesn’t contain ribosomes
24
Q
what is a vesicle
A
fluid-filled membrane enclosed intracellular cargo container
25
when is SER abundant
in cells that are specialised in lipid metabolism
26
what are the SER like in the liver
contain enzymes specialised for detoxifying harmful substances produced within the body or from outside the body.
27
what is SER called in muscle cells
sarcoplasmic reticulum
28
what does the sarcoplasmic reticulum store
calcium used in the process of muscle contraction
29
what does golgi complex consist of
stack of flattened, slightly curved membrane enclosed sacs
30
what happens in the golgi complex
proteins from the ER are modified into their final form e.g. have a carbohydrate attached
31
what is exocytosis
vesicle moves to periphery, fuses with the plasma membrane, opens and empties its contents to the outside
= movement OUT of the cell
32
what do secretory vesicles only fuse with
the plasma membrane
33
what are lysosomes
small membrane-enclosed organelles that break down organic molecules
34
how are lysosomes formed
by budding from the golgi complex
35
what does lysosome contain
powerful hydrolytic enzymes
36
what do hydrolytic enzymes catalyse
hydrolysis
37
what is hydrolysis
reactions that break down organic molecules by the addition of water at a bond site
38
what does hydrolysis mean
splitting of water
39
how is extracellular material brought into the lysosomes
through the process of phagocytosis
40
what is phagocytosis a type of
endocytosis
41
what is endocytosis
internalisation of extracellular material within a cell
42
what are the 3 types of endcoytosis
- pinocytosis
- receptor mediated
- phagocytosis
43
what is pinocytosis
droplet of extracellular fluid is taken up non-selectively
44
how does pinocytosis occur
plasma membrane dips inwards forming a pouch that contains a small amount of ECF it then seals at the surface of the pouch trapping the contents
45
what is dynamin
protein responsible for pinching off the endocytic vesicle
46
is receptor-mediated endocytsosis selective or non-selective
selective
47
what is phagocytosis
cell eating
48
can all cells undertake phagocytosis
no only certain cells
49
what is the main type of cells that do phagocytosis
white cells
50
what is it called when a white cell extends its surface
pseudopods
| they surround or engulf the particle and trap it within the vesicle
51
what fuses with the phagocytic cell
lysosome
52
what are peroxisomes
membranous organelles that produce and decompose hydrogen peroxide
53
where do peroxisomes arise
from the ER/golgi apparatus
54
what do peroxisomes contain
oxidative enzymes
55
what do oxidative enzymes do
use oxygen to strip oxygen form certain organic molecules
56
what are mitochondria known as
the energy organelles
57
example of where mitochondria may be
in muscle cells of the heart
58
mitochondria have their own DNA
| true or false
true
59
what is the mitochondria membrane like
double
60
what increases the surface area in mitochondria
cristae
61
what is the inner gel like solution called in mitochondria
matrix
62
how are the 2 membranes of the mitochondria separated by
narrow intermembrane soace
63
what is the energy currency in the body
ATP
64
what are dietary carbohydrates broken down into
glucose
65
can glucose be absorbed by the blood
yes
66
how is ATP generated in cytosol
glycolysis
67
how is ATP generated in mitochondrial matrix
TCA cycle
68
how is ATP generated in mitochondrial inner membrane
oxidative phosphorylation
69
what is produced from glucose in glycolysis
2x pyruvate
70
how many ATP are generated in glycolysis
2
71
where does the pyruvate from glycolysis go
into mitochondria matrix
72
what does pyruvate become in the mitochondria matrix
acetyl-CoA
73
what cycle does acetyl-CoA join
TCA cycle
74
how many reactions in TCA cycle
8
75
what does acetyl-CoA combine with in TCA cycle
oxaloacetate
76
what does acetyl-CoA + oxaloacetate become
citrate (6C)
77
what does oxidative phosphorylation use
the released hydrogen
78
what 2 processes does oxidative phosphorylation use
1. electron transport system
| 2. ATP synthase
79
what does electron transport system consist of
electron carriers found in 4 large proteins complexes (1-4)
80
what is the link between TCA cycle and electron transport system
NADH
| FADH
81
how does NADH act as a link
it combines with the free energy
82
what drives ATP synthesis
the H+ gradient generated by the electron transport system
83
what energy source works at complex I
NADH
84
what energy source works at complex II
FADH
85
how many ATP does oxidative phosphorylation produce
28
86
how many ATP does one glucose synthesise
32
87
is more energy produced aerobically or anaerobically
aerobically
88
how far can the degradation of glucose go in anaerobic conditions
to the end of glycolysis
89
what is pyruvate converted to in anaerobic conditions
lactate
90
what are amino acids used for
protein synthesis
91
is ATP stored in the mitochondria
no
92
do red blood cells contain mitochondria
no
93
how do red blood cells get their energy
via glycolysis
94
do red blood cells have a nucleus
no
95
what do ribosomes do
protein synthesis
96
how do ribosomes undertake protein synthesis
by translating mRNA into chains of amino acids
97
how many proteins does one mRNA encode for
one
98
where do ribosomes exist
- free in the cytosol
| - attached to RER
99
what are the 3 binding site for tRNA in ribosomes
E
P
A
100
what is the A site
where incoming tRNA with a specific amino acids binds
101
what is the P site
tRNA carrying the growing chain is bound to mRNA
102
what is the E site
where empty tRNA is bound prior to release
103
what is centrosome
cell centre
104
where do microtubules radiate
outward from the centrosome
105
what do microtubules do
anchor organelles and serve as highways for which vesicles are transported
106
what can centrioles form
cilia and flagella
107
what is cytosol
the semiliquid portion of the cytoplasm that surrounds organelles
108
what occurs in cytosol
- enzymatic regulation
- protein synthesis
- storage of fat, carbohydrate
109
what are inclusions
excess nutrients not used for ATP production
110
what is most important storage product
fat
111
where is fat storage
adipose tissue
112
what is glycogen
storage form of glucose
113
where is glycogen stored
liver and muscle
114
what does cytoskeleton do
support and organise cell components and control their movements
115
what makes up cytoskeleton
- microtubule
- intermediate filament
- microfilament
116
what makes up microfilament
actin
117
examples of intermediate filament
keratin
118
role of microtubules
help maintain asymmetric cell shapes and play a role in complex cell movements
119
what is the largest of the cytoskeleton
microtubules
120
what makes up microtubules
tubulin
121
what is microtubule essential for
maintaining the shape of the cell
122
what does microtubule contain
- kinesin
| - dynein
123
what direct does dynein move
towards the centrosome
124
what is the dominant structural form of cilia and flagella
microtubules
125
what is function of lysosome
cells digestive system, destroys foreign substances
126
function of inclusion
store excess nutrients
127
function of microfilament
contraction
128
what is function of intermediate filaments
resist mechanical stress
129
are cilia and flagella intracellular or extracellular organisms
intracellular
130
where are cilia found
respiratory tract
| female oviduct
131
role of cilia
keep foreign bodies out of the lung by sweeping motion
132
what are the only cells that have flagella
sperm
133
what is shorter cilia or flagella
cilia
134
where do cilia and flagella arise
centrioles
135
what happens in mitosis
DNA containing chromosomes of the nucleus are replicated
| results in 2 identical sets
136
how are the replicated chromosomes pulled apart
by mitotic spindle
137
what is the mitotic spindle made of
microtubules
138
what are microfilaments important in
cellular contractile systems and mechanical stiffeners
139
what is the smallest element of cytoskeleton
microfilament
140
what is microfilament composed of
actin
141
how many strands is actin
2
142
what are the 4 humans cells that can move on their own
- sperm
- white cells
- fibroblast
- skin cells
143
how does sperm move
by flagella
144
how do the 3 other cells move on their own
amoeboid movement
145
what does amoeboid movement depend upon
actin filaments
146
what cells are the most active crawlers in the body
white cells
147
where do white cells go
to areas of infection or inflammation
148
what do fibroblast do
go to wounds and help repair the damage
149
what are fibroblast responsible for
scar formation
150
what do microfilament help strengthen
microvilli
151
where are microvilli
- small intestine
| - kidney tubules
152
what are microvilli
hair like projections on epithelial surfaces
153
what do microvilli do
increase surface area available for absorbing digested nutrients
154
what are intermediate filaments important in
mechanical stress
155
how do intermediate filaments appear
irregular, threadlike
156
what do intermediate filaments form
tough, durable fibres
157
how many types of intermediate are found in cells
one
158
where are neurofilaments found
in the nerve cell axons
159
what intermediate filament is found in skin
keratin
160
what other features are keratin structures
hair and nails
161
what is amyotrophic lateral sclerosis (ALS)
progressive degeneration and death of motor neurones
162
what can ALS lead to
gradual loss of control of skeletal muscles, including those used for breathing and can lead to death
