Unit 1 - Cell Membranes Flashcards

1
Q

Membranes are composed of a double layer of

A

phospholipid molecules with embedded protein molecules

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

Membrane structure is often described as

A

fluid mosaic

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

Membrane structures are fluid mosaic. Fluid because

A

the molecules are constantly moving

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

Membrane structures are fluid mosaic. Mosaic because

A

the proteins sticking out of the phospholipid bilayer are likened to the pattern seen in a tile mosaic floor

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

Only ______ molecules can pass through the phospholipid layer

A

fat soluble

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

Most important cell molecules are

A

soluble in water

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

Most cell molecules if they are small enough can only pass through the membrane via

A

pores in the embedded protein molecules

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

Membranes are ________ permeable

A

Selectively

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

All cells are enclosed by a plasma membrane which controls the molecules that

A

enter and leave a cell and so maintain a constant environment within a cell

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

Water enters or leaves the cell by

A

osmosis

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

Osmosis is the movement of water molecules from

A

a region of higher water concentration to a region of lower water concentration through a selectively permeable membrane

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

The body must maintain a constant blood water concentration so that the body cells

A

neither shrink nor burst

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

Blood cells would _____ if the plasma had a lower water concentration

A

SHRINK

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

Blood cells would _____ if the plasma had a higher water concentration

A

BURST

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

HYPERTONIC is when the plasma has a

A

lower water concentration

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

HYPOTONIC is when the plasma has a

A

higher water concentration

17
Q

Diffusion is the movement of molecules from a

A

high concentration to a lower concentration

18
Q

Fat soluble molecules diffuse through

A

phospholipid bilayer

19
Q

Small molecules diffuse through

A

protein channels

20
Q

Oxygen and glucose diffuse into the cell because their use in

A

respiration produces a lower concentration

21
Q

CO2 released by respiration _____ out of the cell

A

diffuses

22
Q

Active transport is the movement of molecules from a

A

low concentration to a higher concentration against a concentration gradient

23
Q

The concentration of molecules in a cell can be maintained at a ______ or ______ concentration than in plasma

A

higher, lower

24
Q

Active transport is

A

selective

25
Q

Active transport requires energy in the form of ____ and __________

A

ATP and special carrier molecules in the membrane

26
Q

Active transport depends on

A

enzymes and ATP

27
Q

Active transports is affected by

A

temperature, oxygen, glucose availability and respiration inhibitors

28
Q

Active transport carriers are often called

A

‘pumps’

29
Q

Some active transport carrier molecules have a dual role in that they

A

exchange one type of ion for another

30
Q

An example of an active transport carrier molecule is the

A

sodium/potassium pump

31
Q

Endocytosis is the process by which a cell

A

engulfs and takes in large particles

32
Q

There are two types of endocytosis:

A

Phagocytosis and Pinocytosis

33
Q

Phagocytosis means

A

cell eating

34
Q

Pinocytosis means

A

cell drinking

35
Q

Phagocytosis is the engulfing of large solid particles and then the contents of a vesicle are

A

digested

36
Q

Pinocytosis is the formation of

A

small liquid filled vesicles

37
Q

Exocytosis is the reverse of endocytosis and allows its contents to be

A

expelled from the cell

38
Q

Endocytosis allows the cell to acquire

A

hormones, lipids and protein

39
Q

Exocytosis allows the secretion of products such as

A

enzymes, glycoproteins and hormones