The cell cycle Flashcards Preview

Phase 1 week 4 cancer > The cell cycle > Flashcards

Flashcards in The cell cycle Deck (28):
1

Name the 2 phases of the cell cycle

Interphase and the mitotic phase

2

What makes up interphase

G1, G0, S phase and G2

3

What makes up mitotic phase

Prophase, metaphase, anaphase, telophase, cytokinesis

4

What is the longest part of the cell cycle

G1

5

What is the shortest part of the cell cycle

mitotic phase

6

Describe G1

• Genes involved in cell cycle progression are switched off so the cell cannot initiate a new round of initiation and cell proliferation.
• If there is a poor nutrient suplly/ if there are antiproliferative stimuli’s present, the cell cycle Is delayed and the cell will exit the cycle to the G0 phase
• If there is a good nutrient supply and positive proliferative stimuli, the cell will pass through the regulator off the cycle, resulting in DNA replication and cell division to occur

7

Describe G0

• This is a highly regulated stage of the cell cycle
• In this stage, cells normally become differentiated to form specialised functions, and therefore no longer undergo cell division.

8

Describe S phase

The pre-replication complex that forms during the G1 phase that ensures that DNA replication only occur once is dismantled, resulting in the formation of 2 sister chromatids. Thee 2 sister chromatids are linked by cohesion

9

Describe G2

• Enzyme activity triggers the entry of the cell into the mitotic stage. A checkpoint is present here, and if un-replicated/damaged dna is detected, then the entry of the cell into the mitotic phase is delayed.

10

Describe prophase

• This is where the chromosome condenses. The centromeres separate, forming the 2 poles of the spindle fibres.

11

Describe metaphase

• Here the chromosome attaches to the spindle fibre at the pole of the cell.

12

Describe anaphase

• 2 sister chromatids are separated by the spindle fibres separating and being pulled apart to different ends of the cells

13

`Describe telophase

• The nuclear envelope reforms on the surface of the chromatin

14

Describe cytokinesis

• The 2 newly formed daughter cells separate from one another

15

Describe the g1 checkpoint

Check for DNA damage and favourable environmental conditons. Involves retinoblastmo

16

Describe G2 checkpoint

Check for damaged and unreplicated DNA

17

Describe mitotic checkpoint

Checks correct chromosomal attachment to spindle

18

Describe cyclin dependent kinase role in cell cycle regulation

During g1, cyclin proteins accumulate. These combine with kinase to form CDKs.
CDKs cause phosphorylation of proteins that stimulate the cell cycle.
• Retinoblastoma (Rb) restricts progression from the g1 phase to s phase. Rb binds to a transcription factors
• When cell are about to enter the s phase, CDKs phosphorylate the Rb protein, inhibiting its activity so it can no longer bind to the transcription factor.
• Transcription factor released and transcripts genes that are require for dna replication, allowing cell to enter s phase.

19

At what stage of the cell cycle does nuclear division occur

mitotic

20

Name a characteristic that highlights malignant tumours metastatic ability

They can give rise to distant secondaries

21

What does VEGF stimulate in tumours

stimulates the formation of a blood supply for tumour

22

Define neoplasm

a new growth

23

Define anaplastic

describes the undifferentiated appearance of malignant cells

24

Define dyssplastic

containing abnormal cells or showing abnormal development.

25

Define metaplastic

the reversible transformation of one differentiated cell type to another differentiated cell type

26

What reactions do kinase enzymes catalyse

phosphorylation

27

What prevents end to end chromosome fussion

telomeres

28

What is the name of a tumour of the epithelial cells

carcinoma