Molecular bio, cell cycle, kinetics, genomics, etc.

Question 1

How do cells regulate their size by coordinating growth with division at the Restriction point (“R”) in G1 phase

Answer 1

There are homeostatic mechanisms to regulate size. When your reach the critical size, you are then able to go into S phase. (only violated in the embryo). The restriction point is where this homeostatic sensing occurs. At restriction point, cells can also got to G0 phase, or exit to do meiosis to form germ cells. After restriction point, even if there is an issue, the cell is committed and can’t stop

Question 2

What happens in the S phase?

Answer 2

Synthesis, where DNA/chromosomes is replicated.

Question 3

What happens in M phase?

Answer 3

Mitosis, DNA is divided to go to the two daughter cells

Question 4

What is the main goal of the somatic cell cycle

Answer 4

ensure exact duplication of the genome in S phase followed by exact of division of the genome in M phase to produce identical daughter cells.

Question 5

how cells do prevent re-replication of their genomes?

Answer 5

by keeping the assembly and activation of replication complexes in separate cell cycle phases. G1, you can only build the pre replication complex. In S you can only activate the already building complexes

Question 6

What is the G0 stage?

Answer 6

It is a resting phase

Question 7

What is CDK?

Answer 7

cyclin dependent kinase (constant level in all stages of cell cycle). it is the enzyme that regulates the cell cycle. The kinase subunit is not active until cyclin binds. Cyclin levels fluctuate throughout the cell cycle. CDK activating kinase phosphorylates CDK to activate it after it binds cyclin (binding cyclin is the huge regulatory part)

Question 8

know that genomic instability either by chromosome re-replication in S phase or mis-segregation during mitosis produces human diseases such as cancer and birth defects (trisomy 21).

Answer 8

TBA

Question 9

Describe the CDK, cell cycle

Answer 9

Add growth factors and hormones, to set of a kinase pathway, to express cyclinD1, 2, 3. The cyclin binds CDK 4 and 6. These, along with CDK 2 and cyclinE block retinoblastoma protein, which blocks the cell cycle by keeping you at the restriction point. When all signals are present, the RB is phosphorylated which inhibits it.

Now we are in S phase were we activate CDC7 Kinase, binding Dbf4, phorphorylating protiens involved in DNA synthesis. Then you move into the rest of the cycle. using other CDKs and cyclins

Question 10

compare the cell cycle of somatic cells (mitosis) with that of germ line cells (meiosis), which produces haploid gametes.

Answer 10

There are two phases of divisions in meiotic cells

Question 11

know that differentiated, post-mitotic cells such as neurons are stuck at the “R” point in that they continue to grow without cycling

Answer 11

TBA

Question 12

know how alterations in many cell cycle regulators that are found in cancer cells are being used for patient diagnosis and prognosis.

Answer 12

TBA

Question 13

understand the importance and the mechanism of cell cycle checkpoints in maintaining genomic stability.

Answer 13

TBA