Brainscape's Knowledge GenomeTM

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


See full index

biology module 2- foundations in biology > 2.5 biological membranes > Flashcards

2.5 biological membranes Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is tonoplast

A

the membrane surrounding the vacuole

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

is the nuclear envelope a membrane

A

yes

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

the membrane at the outside of the cell can be called…

A

the plasma membrane or the cell surface membrane

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

membranes are - permeable

A

partially

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

cell membranes control…

A

what can enter and exit the cell

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

cell membranes are used in cell

A

signalling

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

cell membranes provide - for enzymes

A

attachment sites

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

cytosol is…

A

an area of cytoplasm with no organelles in it

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

cell membranes compartmentalise, which means that they…

A

produce different compartments inside cells

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

phospholipid heads are

A

hydrophilic

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

phospholipid tails are

A

hydrophobic

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

what are the bonds in phospholipids?

A

ester bonds

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

what is formed when phospholipids are put in water?

A

micelles

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

what did Gorter and Grendel propose and when?

A

that the cell membrane is formed of a phospholipid bilayer, 1925

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

what was Davson-Danielli wrong about?

A

he said that proteins formed a layer on top of the membrane, but they are actually embedded in the membrane

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

who proposed the fluid mosaic model?

A

Singer and Nicholson

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

what model do we use for the plasma membrane structure?

A

the fluid mosaic model

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

proteins move more freely in - phospholipids, because…

A

unsaturated, they are bent and less rigid

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

what makes ATP?

A

ATP synthase (in the mitochondria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

can fat soluble molecules go through the phospholipid bilayer?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

a glycocalyx consists of…

A

a lipid and a glycolipid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what proteins are present in the plasma membrane?

A

peripheral proteins, enzyme or signalling proteins, glycoproteins, transport proteins, integral proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are the transport proteins? 4

A

passive carrier protein, active carrier protein, channel protein, gated channel protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

integral and intrinsic proteins…

A

span the whole plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

peripheral and extrinsic proteins…

A

are found in one layer of the plasma membrane only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

channel proteins are - in the plasma membrane

A

pores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

channel proteins allow movement of - or - molecules, eg.

A

large or hydrophilic, glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

channel proteins are often gated so that…

A

they only allow one type of ion through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

channel proteins may be gated, which means they can…

A

open and close to allow certain things through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

carrier proteins are often used in - using - energy

A

active transport, ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

carrier proteins often have a particular shape so that

A

specific molecules fit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

a glycocalyx is a - chain

A

carbohydrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

glycocalyxs form - bonds with -, helping to stabilize the membrane structure

A

hydrogen, water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

aggregating means

A

bringing together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

glycocalyxs are involved in cell adhesion for

A

aggregating cells into tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

glycocalyxs act as receptors for

A

chemical signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

glycolipids in the glycocalyx act as cell identity markers or -, allowing…

A

antigens, the immune system to recognise them as self or non-self

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

cholesterol is found between - of a plasma membrane

A

the tails in the phospholipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

the function of cholesterol in the plasma membrane is…

A

to regulate fluidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

at high temperatures, cholesterol makes the plasma membrane more/less fluid

A

less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

at low temperatures, cholesterol makes the plasma membrane more/less fluid

A

more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

the plasma membrane being more fluid when it is colder is useful as it prevents…

A

the membrane from freezing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

lipid soluble molecules go through

A

the phospholipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

polar or soluble molecules go through

A

hydrophilic channels created by channel proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

endocrine systems signal to cells

A

over large distances

46
Q

panacrine systems signal to cells

A

to other cells locally

47
Q

autocrine systems signal

A

within the cell or to cells of the same type

48
Q

the ‘message molecule’ sent is called the - or the -

A

signal or stimuli

49
Q

the most common types of signal or stimuli are

A

hormones

50
Q

the detect signals, cells must have sensors called -

A

receptors

51
Q

receptors are often

A

proteins

52
Q

non polar signals (such as testosterone and oestrogen) are able to… and bind to …

A

diffuse directly through the phospholipid bilayer, intracellular receptors

53
Q

polar signals must bind to the membrane bound receptors, which are the - proteins

A

intrinsic

54
Q

5 steps of cell signalling:

A
  1. stimuli
  2. receptors
  3. transducers
  4. amplifiers
  5. intracellular responses
55
Q

a ligand is the

A

primary messenger

56
Q

hormones are - messengers transported in the -

A

chemical, blood

57
Q

target cells are any cells with a - for

A

receptor, the hormone

58
Q

the hormone and the receptor on the target cell bind due to

A

their complementary shapes

59
Q

channel proteins travel to- to let - into the cell

A

the cell membrane, glucose

60
Q

binding causes the target cell to

A

react in a certain way

61
Q

under normal circumstances, are there any channel proteins present in the plasma membrane?

A

yes

62
Q

when blood glucose levels rise, the hormone - is secreted into the blood by the -

A

insulin, pancreas

63
Q

medicinal drugs can interfere with

A

receptors

64
Q

beta blockers block receptors to prevent…

A

the heart muscle increasing the heart rate if it would be dangerous for the patient

65
Q

some drugs mimic natural receptors which people lack, eg in

A

schizophrenia

66
Q

drugs blocking receptors form

A

drug- receptor complexes

67
Q

painkillers attach to receptors and block - from travelling along the -

A

pain signals, nerve

68
Q

drugs can do 2 things:

A
  • mimic natural receptors

- block receptors

69
Q

how does botox work?

A

it uses a toxin from the bacterium clostridium botulinum, the toxin binds to the receptors on muscle fibres, prevents them working and causes paralysis, reduces wrinkling of the skin

70
Q

what is theory of Brownian Motion?

A

molecules move around randomly and bump into each other, and so tend to fill out the space that they are in

71
Q

diffusion occurs down a

A

concentration gradient

72
Q

diffusion is always

A

passive

73
Q

diffusion can be - or -

A

simple or facilitated

74
Q

what happens at equilibrium

A

the reaction rate is equal in both directions

75
Q

which molecules go through channel proteins

A

large or polar molecules

76
Q

is facilitated diffusion active

A

no

77
Q

how wide is the phospholipid bilayer

A

7nm

78
Q

how wide is the channel protein

A

0.8nm

79
Q

what can move by osmosis

A

only water

80
Q

pure water has a potential of

A

0

81
Q

which symbol represents water potential

A

psi

82
Q

diffusion occurs across a

A

partially permeable membrane

83
Q

why are plant cells not haemolysed

A

they have a cell wall which prevents it

84
Q

plant cells, water moves in so cell is

A

turgid

85
Q

animal cells, water moves in so cell is

A

haemolysed

86
Q

plant cells, water moves out so cell is

A

flaccid or plasmolysed

87
Q

animal cells, water moves out so cell is

A

crenated

88
Q

what is a hypertonic solution

A

something with a very low water potential

89
Q

what is plamolysis

A

when water moves out of a cell, causing the vacuole to shrink and cytoplasm to move away from the cell wall

90
Q

what is the incipient point of plasmolysis

A

when 50% of cells have been plasmolysed

91
Q

what is bulk transport

A

moving large quantities of material in or out of the cell

92
Q

endocytosis is

A

moving large quantities of material into the cell

93
Q

exocytosis is

A

moving large quantities of material out of the cell

94
Q

what type of energy does active transport need

A

ATP

95
Q

when is active transport used

A

when diffusion isn’t quick enough or when the movement is against a concentration gradient

96
Q

cells involved in active transport have lots of

A

mitochondria

97
Q

why are most carrier proteins one way

A

because otherwise particles would want to move back by diffusion

98
Q

the shape of carrier proteins is

A

complementary

99
Q

carrier proteins are complementary so that

A

they only allow specific molecules to enter snd exit the cell

100
Q

the two types of endocytosis are

A

pinocytosis and phagocytosis

101
Q

pinocytosis is

A

the cell taking in liquids

102
Q

phagocytosis is

A

the cell taking in solids

103
Q

an example of phagocytosis is

A

white blood cells engulfing and digesting pathogens

104
Q

is bulk transport active or passive

A

active

105
Q

why is bulk transport active

A

because it uses energy to transport material in vesicles along the cytoskeleton

106
Q

exocytosis example

A

insulin exiting the cell

107
Q

endocytosis example

A

pathogens entering the cell

108
Q

why is beetroot used to investigate the effect of temperature on cell membranes

A

because their red cell sap is naturally coloured and easy to see

109
Q

why does temperature effect cell membranes

A

because phospholipids break and proteins denature, and the plasma membrane melts. The tonoplast is broken and cell sap can escape from the vacuole.

110
Q

what steps happen to the cell membrane as temperature is increased

A
  1. proteins are denatured as the bonds in their tertiary structure are broken
  2. phospholipid membrane bonds break
  3. rate of diffusion increases
111
Q

how do we conduct an experiment to investigate the effect of temperature on cell membranes?

A
  1. place test tubes with 10cm3 of water into water baths set at 30, 40, 50 and 70, and leave one at room temperature. Leave for 15 mins to equilibrate.
  2. cut beetroot into identical cylinders measured with a ruler and rinse and dry them
  3. place the beetroot cylinders into test tubes and leave for 10 mins
  4. remove the test tubes, remove the beetroot and swirl the liquid
  5. place liquid into cuvettes and measure light absorption, record data in table and plot graph
112
Q

how do we investigate osmosis in an artificial cell?

A
  1. create a dilution series of 1.0, 0.8, 0.4, 0.2 and 0.1 mol dm3
  2. cut visking tubing into 5 equal sections and tie then ends in knots
  3. fill tubing 1/3 full with 0.4 mol dm3 solution
  4. measure the mass of each concentration initially
  5. place the artificial cells into each concentrated solution for 20 mins and then remove and weigh mass
  6. create a table recording concentration, initial mass, final mass, mass change, and percentage change

biology module 2- foundations in biology (6 decks)

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