Mitogenic Signal and Cell Division

Question 1

Where are mitogenic signals transduced?

Answer 1

Inside the cell and activates TFs

Question 2

What are TFs?

Answer 2

Proteins which control gene expression

Question 3

What are TFs activated by and what do they do?

Answer 3

• Activated by a proliferative signal/mitogen

- Encode genes which result in the synthesis of proteins required to activate and control cell division

Question 4

What are the 4 phases of cell division?

Answer 4

• G1 = Grow in size and start to make enough organelles for two cells
• S = Replicates DNA
• G2 = Check DNA has been correctly replicated
• G2 = Condense DNA in readiness for sister chromatid separation
• M = Distribute chromosomes equally and divide the cytoplasm to make two cell

Question 5

What are the two control points in cell division?

Answer 5

• R-point = Prevents cells from entering S phase

- G2/M point = Prevents cell progressing to M phase

Question 6

Which substances act as regulators for these control points in cell division?

Answer 6

• Cyclins

- Cycling-dependant kinases (Cdks)