Biochemistry Block Ii: Cell Cycle, Purines And Pyrimidines Sping 2010

Front 1

This phase in the cell cycle is a period of growth and preparation for DNA replication:

Back 1

G1

Front 2

Cells in this phase can proceed through the rest of the cell cycle or withdraw into G0 based on factors such as nutrients available or DNA damage:

Back 2

G1

Front 3

Synthesis of PCNA and DNA polymerase alpha are increased during this phase in the cell cycle

Back 3

G1

Front 4

Enzymes necessary for DNA replication are made or activated in this phase of the cell cycle:

Back 4

G1

Front 5

This is the phase in the cell cycle when DNA is replicated:

Back 5

S1

Front 6

Histone protein synthesis is linked to this phase in the cell cycle:

Back 6

S1

Front 7

This is the phase in the cell cycle when cells prepare for cell division:

Back 7

G2

Front 8

This phase in the cell cycle has a checkpoint to ensure that all the DNA has been properly replicated and is intact:

Back 8

G2

Front 9

Repair of double strand breaks by homologous recombination occurs in this phase in the cell cycle:

Back 9

G2/M

Front 10

This phase in the cell cycle is when actual cell division occurs:

Back 10

M Phase/Mitosis

Front 11

In this phase in the cell cycle the replicated chromosomes joined at the centromere align and segregate:

Back 11

M Phase

Front 12

The transition from 2n to 4n is indicative of completion of which phase in the cell cycle?

Back 12

S Phase

Front 13

Which phase(s) in the cell cycle have 2n complement of DNA?

Back 13

G1

Front 14

Which phase(s) in the cell cycle have 4n complement of DNA?

Back 14

G2/M

Front 15

Which phase(s) in the cell cycle have between 2n & 4n complement of DNA?

Back 15

S

Front 16

______ direct CDKs to phosphorylate specific cellular target proteins, altering their activity.

Back 16

Cyclins

Front 17

Amounts of the cyclins vary during the cell cycle and are regulated by ______ ______ _______ in the proteasome.

Back 17

Ubiquitin-dependent degradation

Front 18

Cyclin __ &__ regulate phosphorylation of factors in G1and prevent progression to S unless conditions are right.

Back 18

D & E

Front 19

Cyclin __ sustains DNA replication.

Back 19

A

Front 20

Cyclin __ regulates G2/M and does not prevent cell division unless DNA replication is complete.

Back 20

B

Front 21

What is the major target for the Cyclin D/E:CDK 4/6 Complex? Why?

Back 21

Rb protein, phosphorylation of Rb releives its inhibition of E2F, allowing it to stimulate transcription of genes needed for DNA synthesis.

Front 22

What are the major targets of the Cyclin B:CDK1 complex? Why?

Back 22

Histone H1 and nuclear Lamin proteins. Phosphorylation of H1 is involved in condensation of chromatin to chromosomes and phosphorylation of lamin is involved in the breakdown of the nuclear envelope.

Front 23

Which protein is mutated in over half of all human cancers?

Back 23

Tumor supressor protein P53.

Front 24

______ plays a role in DNA damage control, is activated an stabilized by DNA damage and does not allow replication to proceed in these cases.

Back 24

P53

Front 25

P53 is a transcrption factor that induces synthesis of which two things?

Back 25

P21 and CKI

Front 26

____ binds to and inhibits CDK-Cyclin complexes. This way Rb is unphosphorylated, inhibits E2F and prevents damaged DNA from entering S Phase.

Back 26

P21

Front 27

If P53 activity in a cell is prolonged, it induces genes that cause the cell to enter _________.

Back 27

Apoptosis (allows cells to die rather than replicating DNA)

Front 28

Programmed cell death:

Back 28

Apoptosis

Front 29

Give two reasons for naturally occuring cell death:

Back 29

Cells are no longer needed or irreparably damaged.

Front 30

P53 activated by DNA damage is stabilized and stimulates continuous new synthesis of _____.

Back 30

P21

Front 31

The two apoptosis pathways converge on a common target; ____________.

Back 31

Activation of Caspases

Front 32

Family of cysteine dependent aspartate specific proteases that degrade cellular protein targets:

Back 32

Caspases

Front 33

Caspases are activated in a ________ in which each activated caspase cleaves another.

Back 33

Cascade

Front 34

These two proteins mediate changes in mitochondrial membrane integrity which allow cytochome c to leak out and initiate a caspase cascade:

Back 34

Bax and Bak proteins

Front 35

_______ is an anti-apoptotic protein. It acts by preventing Bak and Bax from altering the mitochondrial membrane.

Back 35

Bcl2

Front 36

Which apoptosis pathway is activated by DNA damage which activates P53?

Back 36

Intrinsic Pathway

Front 37

The Bcl2 family of proteins is related to which pathway of cell apoptosis?

Back 37

The intrinsic pathway.

Front 38

Which apoptosis pathway relies on signal molecules that can be synthesized by circulating immune system cells that bind to surface receptors?

Back 38

The extrinsic pathway.