Cell Biology Flashcards
1
Q
In which germ layer is the nervous tissue formed?
A
Ectoderm
2
Q
In which germ layer does muscle tissue form?
A
Mesoderm
3
Q
In which germ layer does the connective tissue form?
A
Mesoderm
4
Q
In which germ layer does the epithelial tissue form?
A
All germ laters
5
Q
What is terminal differentiation?
A
This is when differentiation in a cell occurs, each time cutting out other possible cell types, until only one cell type is left
6
Q
What are unipotent and pluripotent stem cells?
A
Stem cells which either have a set pathway set out, or multiple possible fates
7
Q
If experimentally relocated what happens to those cells?
A
They will continue to follow the old pathway
8
Q
What causes commitment of a certain cell to follow a specific pathway?
A
Morphogens
9
Q
What are the 3 types of muscle tissue?
A
Cardiac
Smooth
Skeletal
10
Q
Name 4 features of a skeletal muscle
A
- Multinucleated
- Long unbrancbed fibres
- Striated
- Sarcoplasmic reticulum
11
Q
Give 4 features of the smooth muscle tissue
A
- Uninucleate
- Unbranched fibres
- Involuntary contraction
- Unstriated
12
Q
Give 4 features of cardiac muscle
A
Branched fibres
Intercalated discs
Faintly striated
Purkinjinfibres
13
Q
What band is made up of myosin? And is it the thick or thin filament?
A
A band
Thick filament
14
Q
Which band is made up of the actin molecule. And is it the thick or thin filament?
A
I band
Thin filament
15
Q
How does an actin potential cause a contraction?
A
The action potential causes calcium to be released from the sarcoplasmic reticulum, allowing for the ions to bind to the TnC sites on tropmyosin, allowing for cross lineages to form
16
Q
What are the 3 major functions of the epithelial cells?
A
Protection
Secretion
Absorption
17
Q
What are the 4 ,ajar uses of the CT?
A
Storage
Repair
Transport
Protection
18
Q
What are the characteristics of collagen?
A
White
Thick
Unbranched
Strong
19
Q
Equation are the characteristics of elastic fibres?
A
Yellow
Thin
Branched
Stretchy
20
Q
What type of cell makes collagen?
A
Fibroblasts
21
Q
Where are elastic fibres made?
A
Fibroblasts
22
Q
What are the features of a fibroblast cell?
A
Round nucleus
Abundant cytoplasm
Lots of rer
23
Q
What are the characteristics of fibrocytes
A
Flat nucleus
Scant cytoplasm
Little rer
E.g. Tendon
24
Q
What type of tissue are fat cells ?
A
Connective tissue
25
Where is the matrix produced and and what is it prodominatly made up of?
It is made within the fibroblasts and it is predominantly made up of GAGs ( long chain carbohydrates, unbranched)
26
Name 3 ways in which a neural cell is different from a normal cell
It has selective ion channels
It has long processes extending from the cell body
Specialised metabolism
27
What re the role of glial cells?
They maintain and provide nutrition to neural cells
28
What type of cell wraps itself around the axon of a cell and what does this do to the axon
Glial cells wrap themselves around the axon, this produces a myelinated axon
29
What is saltatory conduction?
Intermittent Conduction between nodes of ranvier
30
What happens after ligand- gated ion channels have opened at a post synaptic cleft
The membrane opens sodium channels making the membrane positively charged
31
What type of blood cell transports oxygen around the body
Erythrocytes
32
Where are red blood cells produced
In long bone marrow
33
What's the name for white blood cells
Leukocytes
34
Give examples of granulocytes
Neutrophils, easinophils, basophils
35
Give examples of agranulocytes
Lymphocytes, monocytes
36
What are the 3 layers of the blood vessel called?
Intima
Media
Adventitia
37
What are the 3 germ layers?
1. Endoderm
2. Ectoderm
3. Mesoderm
38
What are the functions of the plasma membrane?
Maintenance of the concentration of the cytosol
Provides a cell boundary
Regulates movement of cellular materials in and out
39
What are membranes solely made up of?
Carbohydrates
Lipids
Proteins
40
What are the two major functions of proteins on the cell membrane?
1. Cell signalling
| 2. Transporting materials across the plasma membrane
41
What are the 4 major properties of the membrane?
Continuous
Selectively permeable
Self repairing
Flexible
42
What is the structure of cholesterol?
Polar head
Rigid steroid ring structure
Non polar tail
43
What are the functions of the proteins in the cell membrane?
Cell signalling
Intercellular interactions
Provide structure to the membrane
Provide permeability
44
What are liposomes used for?
Drug delivery
Delivery of DNA and RNA into cells
Cosmetic surgery
45
What are the three possible methods of lipid movement in a membrane?
Flip flop
Lateral diffusion
Rotation
46
What conditions in c=c bonds, acetyl chains and [cholesterol] leads to the most fluid membrane?
High C=C bonds, low acetyl length, less cholesterol
47
What effect does cholesterol have on membrane permeability?
The more cholesterol the less permeable it is
48
Where are integral membranes found?
In the cell membrane
49
Where are peripheral membrane proteins found?
Attached to the membrane
50
By what 3 methods can peripheral membrane proteins attach themselves to the cell wall?
Able to insert a lipid domain into the membrane
Able to interact with a integral protein
Able to directly bind with lipids
51
What are the advantages of lipid anchoring on membrane proteins?
Mobility at the surface
| Rapid release into extra cellular space
52
What are the 5 major functions of integral membrane proteins?
```
Enzymes
Cell cell recognition
Transport of molecules
Receptors
Carriers
```
53
3 major functions of peripheral membrane proteins?
Maintaining structure
Intracellular transport
Communication, glycoproteins
54
What is the major protein in red blood cells?
Spectrin
55
Peripheral proteins in red blood cells include (3)
Spectrin
Actin
Ankyrin
56
Integral proteins in the red blood cell include(3)
Band 3
| Glycoporins
57
Why do the proteins move slower than phospholipids in red blood cells?
Because they are held in place by the Spectrin and other peripheral proteins
58
What is present in the cell which can prevent movement of phospholipids
Lipid rafts
Tight junctions
Being bound to proteins
59
What enzyme equilibriates lipids and where does it perform its function?
It occurs in the ER
| Scramblase
60
What enzyme works to switch lipids from one membrane envelope to the other and where does it perform its role?
Flippase
| The cell membrane
61
Where are glycolipids found in red blood cells?
Found on the outside of the red blood cell
62
What charge does phosphotydlserine have and where is it usually found?
Negative charge
| Found on the inner membrane?
63
Is sodium and potassium more negative in the intracellular or extracellular fluid?
Sodium- more native in the extracellular matrix
| Potassium- more negative within the cell
64
What is a anti port transport protein
A protein which requires 2 molecules, each moving in different directions across the membranes
65
Which membrane is more positively charged?
The outer surface is more positively charged
66
What 3 factors can mediate active transport?
Coupled carrier
Atp driven pump
Light driven pump
67
What proportion of the cell does the nucleus take up?
10%
68
How was the nucleus thought to have been formed?
Invagination of the membrane of a bacterium, this surrounded the DNA
69
What is the role of the nucleolus?
This is the place where sub units of ribosomes are produced
70
What is the function of the chromatin?
Unpackaged DNA area
71
What is the function of Lamin in the nucleus? (A and b and phosphorylation)
Lamin B tethers to the nuclear envelope
Lamin A binds to Lamin B to create a network of proteins
When polarised, these will dissociate allowing for the chromosomes to move apart
72
What is chromatin
DNA in its unwound form
73
How many subunits make up the nuclear pore?
8 excluding the plug
74
What are the 4 building blocks of the nuclear pore?
Annular
Luminal
Ring
Column
75
In what way is the endoplamic reticulum dynamic
It is able to continuously break and reform in many different shapes
76
What are the 4 major functions of the ER
Detoxification
Storage
Synthesis
Transport
77
What 3 molecules does the SER synthesise?
Synthesises glycerides
Glycogen
And phospholipids, cholesterol
78
Where is calcium stored within the ER complex
The SER
79
How many cisternae are there in the Golgi apparatus
5-6
80
How do the cisternae in the Golgi apparatus communicate with the ER
Through the use of vesicles
81
What are the 3 primary functions of the Golgi apparatus?
Modification and packaging secretions ready for exocytosis
Renewal and modification of the plasma membrane
Delivery of material to other organelles, especially the endocytic pathway
82
What two processes transport molecules from the ER to the Golgi apparatus?
Budding
| The use of tubules
83
What is COPII involved in?
The coat of the budding vesicles which transports it from the ER to the Golgi and Golgi to Golgi only
84
What is the role of COPI
The coat of vesicles moving from Golgi to Golgi and from Golgi to ER
85
What is the role of Cathrin?
Clathrin is the coat of a vesicle after budding towards the membrane
86
What are SNARES?
SNARES are proteins on the surface of the vesicle from the Golgi apparatus which direct the vesicle to where it needs to go
87
What are the two types of snares and where are they found?
V- SNARES- found on the vesicle
T- SNARES- found on the wall of the target plasma membrane
88
What are the 3 processes by which vesicles from the Golgi their target?
Signal mediated diversion to lysosomes
Signal mediated diversion to secretory glands
Constitutive secretory
89
What is endocytosis
The process of bringing molecules in to the cell via budding
90
What are the 3 fates of endocytosed material
Degradation
Storage
Transcytosis
91
What are the 6 methods of bringing material into a cell for endocytosis
Macropinocytosis
Clathrin coated vesicle
Nonocoated vesicle
Phagocytosis
92
What is the role of dynamin?
Dynamin is used to cut coated vesicles from the membrane during budding to allow it to be free in the cytoplasm
93
Give 4 structural features of a mitochondria
Double membrane
Not very big
Outer membrane is the barrier of the organelle
Inner membrane is highly folded
94
Where is mitochondrial DNA inherited from?
The mother
95
What is the primary function of the mitochondria?
Energy production
96
Where does glycolysis occur? And what are the products of it?
Glycolysis occurs in the cytoplasm and produces pyruvate
97
What is usually a key symptom of diseases in mitochondria
Lack of energy
98
What is leber hereditary optic nerve nerve neuropathy?
A disease effected by mitochondria causing vision loss in young adults
99
How many membranes do peroxide mess have?
| Do they contain either DNA or ribosomes?
Peroxisomes have a single membrane
| They have no DNA or RNA in them
100
What is the major role of peroxisomes and what two oxidative enzymes do they produce to do this?
Their function is to remove hydrogen atoms from various organic compounds
1. AIDS in detoxification in the liver
101
What is the net production of ATP and NADH in glycolysis?
2 molecules of ATP
| 2 molecules of NADH
102
What occurs in reaction 1 of glycolysis and which enzyme is used and what use of coenzymes/ apt is used?
Glucose --> glucose 6 phosphate
Hexokinase
One molecule of ATP is consumed(mgATP)
103
What happens in reaction 2 of glycolysis? Are enzymes used?
Is it reversible?
Any coenzymes used?
Glucose 6 phosphate --> fructose 6 phosphate
Phosphoglucose isomerase
Freely reversible
104
What occurs in reaction 3 of glycolysis?
What enzyme is used
Is it reversible
Any coenzymes used
Fructose 6 phosphate --> fructose 1,6 bisohosphate
Phosphofructokinase
1 ATP is used up
Irreversible
105
What happens on reaction 4 of glycolysis
What enzyme is used
Is it reversible
Any coenzymes used?
Fructose 1,6 bisohosphate --> glyceride 3 phosphate and other
Aldolase
Irreversible
No coenzymes used
106
What happens in reaction 5 of glycolysis
What enzyme is used?
Is it reversible
Are any coenzymes used?
DAP--> glycerate 3 phosphate
Triose phosphate isomerase
Reversible
107
What happens in reaction 6 of glycolysis?
Is it reversible
What enzyme is used?
Are any coenzymes used?
Glycerate 3 phosphate --> 1,3 bisohosphoglycerate
Glycerate 3 phosphate dehydrogenase
Reversible
NAD+ to NADH
108
What happens in reaction 7 in glycolysis?
What enzyme is involved?
Is it reversible
Are any coenzymes involved?
1,3 bisphosphoglycerate--> 3 phosphoglycerate
P
Phosphoglycerate kinase
Reversible
ADP--> ATP
109
What is Piercarlo converted to under anerobic conditions?
Lactate
110
What is the net reaction for the links chain reaction
Pyruvate + NAD+ + CoA = CO2 + acetyl CoA + NADH
111
What are the summary products for krebs?
4CO2 6NADH +2FADH2 + GTP
112
What components of the cell ultimately supply the Krebs cycle
Amino acids
Fatty acids
Glucose
113
What is ubiquinone, and How many electrons can it accept?
Ubiquinone is a carrier of electrons
It is fat soluble
It can except 1 or 2 electrons
114
What occurs in complex 1?
NADH to ubiquinone
Transfers electrons from one to the other producing ubiquinol
H+ diffuse into mitochondria cytosol
Ubiquinol diffuses to QH3
115
What happens in complex 2?
Succinate to ubiquinone
| Electrons move from succinate to FAD to QH2
116
What happens in complex 3?
Ubiquinone to cytochrome c
| Cytochrome bc1 complex
117
What happens in complex 4?
Cytochrome c to o2
| Electrons passed to oxygen to form H20
118
What is the role of ATP synthase, where is it found and what's the ratio of subunits
To transport H+ ions though the membrane
Found in the membrane
Has 3 units ration1:2:9-12
119
How is ATP generated by ATPsynthase
H+ goes through the pore causing the molecule to rotate by a 1/3
This causes a conformational change in B subunit
120
What are cell probes used for?
Measure the current across a membrane
121
What did brown discover?
The nucleus
122
What did Schwann and schleiden discover?
All organisms consist of one or more cells
| The. Cell is the basically unit of structure for all organisms
123
Cilia and flagellum are similar, but in what way?
Major functional structure is the axoneme
124
How many micro tubules make up the axoneme
9 + 2 assembly
125
What is the cytoskeleton?
A dynamic complex intracellular network of tubules, filaments and fibres found in all eukaryotes
