Brainscape's Knowledge GenomeTM

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


See full index

Advanced Higher Biology > 1. Key Area 5- Protein Control and Cell Division > Flashcards

1. Key Area 5- Protein Control and Cell Division Flashcards

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

What is the purpose of the cytoskeleton?

A

To give mechanical support and shape to cells

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

What does the cytoskeleton consist of?

A

Different protein structures including microtubules which are found in all eukaryotic cells

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

What are microtubules composed of?

A

They are hollow cylinders composed of the protein tubulin. They radiate from the microtubule organising centre (MTOC) or centrosome

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

What is the function of microtubules?

A

Control the movement of membrane-bound organelles and chromosomes

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

What does cell division require?

A

The remodelling of the cytoskeleton

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

What does the formation and breakdown of microtubules involve?

A

Polymerisation and depolymerisation of tubulin

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

What do microtubules form?

A

The spindle fibres that are active during cell division

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

What does the cell cycle consist of?

A

Interphase and Mitotic phase

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

What does interphase involve?

A

The growth and DNA synthesis including G1: growth phase, S phase: during which the DNA is replicated, and G2: a further growth phase

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

What does the mitotic phase involve?

A

mitosis and cytokinesis

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

What occurs in mitosis?

A

the chromosomal material is separated by the spindle microtubules

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

When and what occurs in cytokinesis?

A

Following mitosis, the cytoplasm is separated into two daughter cells

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

What does mitosis consist of?

A

PMAT
prophase
metaphase
anaphase
telophase

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

What happens in prophase?

A

DNA condenses into chromosomes consisting of sister chromatids. Nuclear membrane breaks down, spindle microtubules extend from the MTOC (microtubule organising centre) by polymerisation and attach to chromosomes via their kinetochores in the centromere region

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

What happens in metaphase?

A

Chromosomes are aligned at the metaphase plate (equator of the spindle)

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

What happens in anaphase?

A

As spindle microtubules shorten by depolymerisation, sister chromatids are separated and the chromosomes are pulled to opposite poles

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

What happens in telophase?

A

The chromosomes decondense and nuclear membranes are formed around them

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

Define the mitotic index

A

A measure of the activity of a particular tissue. The number of cells in M/ total cells as a percentage

19
Q

What is progression through the cell cycle controlled by?

A

Checkpoints

20
Q

What are checkpoints?

A

They are mechanisms within the cell that assess the condition of the cell during the cell cycle and halt progression to the next phase until certain requirements are met

21
Q

What accumulates during cell growth which is involved in regulating the cell cycle?

A

Cyclin proteins

22
Q

What do cyclins combine with and activate?

A

cyclindependent kinases (CDKs)

23
Q

What do active cyclindependent kinases complexes (CDKs) do?

A

They phosphorylate proteins that regulate progression through the cycle. If sufficient phosphorylation is reached, progression occurs

24
Q

Where does the retinoblastoma protein (Rb) acts as a tumour suppressor?

A

At the G1 checkpoint

25
Q

How does the retinoblastoma protein (Rb) act as a tumour suppressor?

A

By inhibiting transcription of genes that code for proteins needed for DNA replication

26
Q

What inhibits the retinoblastoma (Rb) protein?

A

Phosphorylation by G1-cyclin-CDK

27
Q

What is the order of the cell cycle?

A

G1 to S phase to G2 to M phase

28
Q

What is assessed at the G2 checkpoint?

A

The success of DNA replication and any damage to DNA is assessed

29
Q

What does DNA damage trigger at the G2 checkpoint?

A

DNA damage triggers the activation of several proteins including p53 that can stimulate DNA repair, arrest the cell cycle or cause cell death.

30
Q

What is the function of the protein p53?

A

Stimulates DNA repaire, arrests the cell cycle or causes cell death

31
Q

What controls the progression from metaphase to anaphase?

A

The metaphase checkpoint

32
Q

What happens at the metaphase checkpoint?

A

Progression is halted until the chromosomes are aligned correctly on the metaphase plate and attached to the spindle microtubules

33
Q

What does an uncontrolled reduction in the rate of the cell cycle result in?

A

Degenerative disease

34
Q

What does an uncontrolled increase in the rate of the cell cycle result in?

A

Tumour formation

35
Q

What is the function of a proto-oncogene?

A

It is a normal gene which is usually involved in the control of cell growth or division which can mutate to form a tumour-promoting oncogene

36
Q

What is apoptosis triggered by?

A

Cell death signals which can be internal or external

37
Q

Once external death signal molecules bind to a surface receptor protein, what do they trigger?

A

A protein cascade within the cytoplasm

38
Q

What is an example of an external death signal?

A

The production of death signal molecules from lymphocytes

39
Q

What is an example of an internal death signal?

A

DNA damage

40
Q

What does an internal death signal resulting from DNA damage cause?

A

The activation of p53 tumour-suppressor protein

41
Q

What does both types of death signal result in?

A

The activation of caspases (types of protease enzyme) that cause the destruction of the cell

42
Q

Why is apoptosis essential during the development of an organism?

A

To remove cells no longer required as the development progresses or during metamorphosis

43
Q

Even in the absence of growth factors, what may cells initiate?

A

Apoptosis

Advanced Higher Biology (10 decks)

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