Brainscape's Knowledge GenomeTM

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


See full index

alevel biology OCR > 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

Role of the phospholipid.

A

Form a partially permeable barrier to substances that separate organelle interiors from cytoplasm or cytoplasm from extra cellular environments.

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

Role of proteins in fluid mosaic model?

A

Channel and carrier proteins

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

Role of glycoproteins and glycolipids

A

Form the glycocalx which acts as a material that binds together.

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

Role of cholesterol in fluid mosaic model

A

Decrease the fluidity of membrane and increase mechanical stability.

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

Is a phosphate head hydrophilic or hydrophobic?

A

Hydrophilic

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

Is a fatty acid tail hydrophobic or hydrophilic?

A

Hydrophobic

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

What’s the difference between simple and facilitated diffusion?

A

Simple diffusion is along the direction of the conc gradient whereas facilitated is both.

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

In what solutions can facilitated diffusion occur?

A

Water or charged ions

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

In what solution can simple diffusion occur?

A 
Lipids (oestrogen) 
Non polar (gas)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is osmosis?

A

Movement of water molecules from a high to low water potential across a partially permeable membrane

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

What is water potential?

A

The tendency of water molecules to diffuse to another region

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

What is water potential measured in?

A

kPa water=0kPa

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

What does having a low water potential mean?

A

There is a low tendency of water to diffuse elsewhere.

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

What does hypertonic mean?

A

environment outside of cell has a higher conc than in the cell itself.

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

What does isotonic mean?

A

Concentration is equal inside and outside the cell.

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

What does hypotonic mean?

A

Conc outside of cell is lower than inside the cell.

17
Q

What are the hypertonic affects?

A

Cremated or plasmolysed cells lack water which means that soluble substances can’t take part in chemical reactions.

18
Q

WhT are the hypotonic effects?

A

Animal cells will undergo lysis and die. Plant cells will become turgid as their vacuoles fill with water

19
Q

Explain the steps of co transport.

A
  1. Na+ actively transported from intestinal epithelial cells to the blood.
  2. This decreases the Na+ conc at the cytoplasm.
  3. Na+ move by facilitated diffusion from intestinal lumen into cells.
  4. Glucose is co transported with Na+ into intestinal epithelial cells.
  5. This increases glucose conc in cell. It will go out of the cell to the blood by facilitated diffusion
20
Q

Name the factors affecting membranes?

A

Temp: phospholipid bilayer melts
Solvents: dissolve phospholipid bilayer

Temp: proteins will denature which decreases strength of membrane.

21
Q

What is the interphase in the cell cycle?

A

Preparation

22
Q

What is mitosis in the cell cycle?

A

Actual division

23
Q

What is cytokinesis in the cell cycle?

A

End of division

24
Q

What is G1 in the interphase?

A

Protein synthesis

25
Q

What is S in the interphase?

A

DNA replication

26
Q

What is G2 in the interphase?

A

New organelles produced

27
Q

Name the order of the interphase

A

G1
S
G2

28
Q

What are the checkpoints in the interphase?

A

They prevent uncontrolled division and repair damaged DNA aswell as maintain undirectionalitity.

29
Q

Stages of mitosis?

A

Chromosome condensing
Chromosome separation
Nuclear division

30
Q

Role of mitosis?

A

Growth
Tissue repair
Asexual reproduction

31
Q

What is it called when a chromosome is attached to a copy of itself.

A

Sister chromatids

32
Q

What are chromatically joined together by?

A

Centomere

33
Q

Name the 5 stages of the cell cycle?

A 
Interphase
Prophase
Metaphase
Anaphase
Telophase
34
Q

What happens in the prophase?

A

Nuclear envelope breaks down
Chromosomes condense
Centrioles replicate and form spindle fibres

35
Q

What happens in the metaphase?

A

Spindle fibres attach to centromere of chromosome

36
Q

What happens in the anaphase?

A

Spindle fibres contract
Centromere splits
Sister chromatids are pulled apart

37
Q

What happens in the telophase?

A

2nuclear envelopes from around the set of chromosomes

38
Q

Why happens to the cytoplasm during cytokinesis?

A

It splits forming 2 identical daughter cells

alevel biology OCR (4 decks)

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