Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MTC > Membranes and membrane transport > Flashcards

Membranes and membrane transport Flashcards

wk 4

1
Q

what are the four types of membranes?

A

nuclear, plasma, mitochondrial and endoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the basic structure of the phospholipid bilayer

A

Hydrophilic head, hydrophobic fatty acid chains with intergral and perhipheral proteins and carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe carbohydrates in phospholid membrane.

A

associated with membrane, attached to lipid and proteins and recognises specific molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what effects the fluidity of the phospholipid membrane?

A

temperature, fatty acid chain length, bonding and presence of cholestrol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what varies in membrane composition?

A

amount of proteins, cholestrol, carbohydrates and lipids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

If the membrane gets more heat….

A

it becomes more fluid as lipids move around

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

if the membrane gets more cold….

A

less fluid as the chains pack tightly together and are laterally organised.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the effect of fatty acids on phospholipid protein?

A

Long chain = more stiff, shorter chain = less stiff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the impact of double bonds in the phospholipid membrane?

A

makes the fatty acids un-saturated which makes the membrane more stiff.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the effect of cholestrol in a low temperature?

A

increases fluidity of the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the impact of cholestrol in a high temperature?

A

decreases fluidity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where are proteins in the phospholipid membrane?

A

freely migrating or anchored to a specific region.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is an example of a protein that is bound to cell wall?

A

Neuronal transmitter protein in plasma membrane of muscle cell. it recognises a chemical signal from a neuron.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the ECM made up of?

A

collagen, fibronectin and heparin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what do membrane proteins bind to?

A

the ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the role of integrins ?

A

maintains structure as it binds to ECM and filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the importance of cholesterol in membrane proteins?

A

membrane integrity, source of production for hormones, vitmian D and bile and regulate s fluidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Is the outside of the cell more postive or negative when compared to the inside? Why

A

Positive. More posotive ions (Ca, K and Na)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is hypertonic (on the outside)?

A

solutes concentrated on the outside of the cell

20
Q

What is isotonic?

A

solute concentration is equal on each side of the cell

21
Q

what is hypotonic (on the outside)?

A

Less solute on the outside of the cell.

22
Q

what is a clinical example of osmosis?

A

Red blood cells.

23
Q

What happnes when red blood cells are hypotonic on the outside

A

not enough solute on the outside, cell takes in water and bursts = poor kidney function

24
Q

What are three types of passive transport?

A

Simple diffusion, facilitated diffusion and osmosis.

25
Q

What can move through simple diffusion?

A

CO2, O2 and lipid soluble subtnaces (steroids)

26
Q

How does simple diffussion occur?

A

The molecules engage in random collisions with like molecules.

27
Q

What is an example of faciliated channel?

A

Aquaporin (in red blood cells and kidney) where water goes through hydrophilic channel

28
Q

How does facilated diffusion with a carrier protein work?

A

molecule binds to specfic carrier –> it chnages shape –> allows to come in

29
Q

what are the two classes of carrier proteins?

A

Symporters and antiporters

30
Q

what are symporters?

A

Simultaneously transports sugar and ion

31
Q

what is an example of symporter carrier protein?

A

Na and Glucose.

32
Q

What are antiporters?

A

Where one solute moves in ONE direction whilst the second moves in ANOTHER.

33
Q

What is an example of a antiporter carrier protein?

A

Na and Ca in cardiac muscles

34
Q

What is primary active transport?

A

When molecules move against the concentration gradient using energy from ATP.

35
Q

How does the Na/K ATPase (primary active) function?

A

3 Na+ bind to protein pump INSIDE cell –> ATP breaks into ADP –> protein pump changes shape –> Na is expelled from the cell –> K binds to protein pump (now open to outside) –> K enters the cell.

36
Q

What is secondary active transport?

A

The energy from the primary transport creates a ion gradient which is used to transport another compound.

37
Q

What is an example of secondary active transport?

A

Na+ gradient using Na symporter

38
Q

How does the Na symporter work?

A

Na moves down concetration gradient –> allows for uphill transport of glucose (cotransportred substate)

39
Q

What is a clinical example of Primary Active transport?

A

Heart disease- Digoxin is a treatment for heart disease as it increases foce of hear contraction. It inhibits Na/K ATPase. This lowers Na gradient = less Ca exported = stronger muscle contractions

40
Q

What are the three processes in which macromolecules move?

A

Phagocytosis, pinocytosis and receptor-mediated endocytosis.

41
Q

How does phagocytosis occur?

A

partcile binds to cell surface –> polymerisation and depolumerisation of actin microfilaments –> vacuole forms –> fuses with lyosomes –> digested by enzymes

42
Q

What are the two roles of receptor- mediated endocytosis?

A

1- uptake of nutrition
2. Waste disposal

43
Q

Describe the mechanism of action for receptor-mediated endocytosis.

A

Plasma membrane folds inwards –> folds into a small pocket around materials –> pocket deepens forming a vesicle –> vesicle separates from plasma and migrates contents to centre

44
Q

What are the main differences between carrier and channel?

A

Binding (carrier binds), speed (channel is faster) and make up (channel= tunnel/pore, Carrier= conformational change)

45
Q

What is the difference between peripheral and integral proteins?

A

Peripheral = surface whilst intergal is all the way through.

46
Q

What is the role of intergrin and how?

A

ntegrins: bind ECM and to actin filaments (part of cytoskeleton) on inside

MTC (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions