Molecular Bio Flashcards Preview

COB Cumulative Final > Molecular Bio > Flashcards

Flashcards in Molecular Bio Deck (114)
Loading flashcards...
1

What are the requirements of a chromosome?

Origin of Replication, telomere, centromere

2

DNA is basepairing is antiparallel because each strand's sequence is complementary to partner. True or false?

true

3

Digestion with ___ break down DNA by cutting between nucleosomes and degrading the exposed DNA between nucleosome core particles (linker DNA)

nucleases

4

Each individual nucleosome core particle consists of __ histone proteins

8

5

Define pseudogenes

duplicated gene that has become irreversibly inactivated by multiple mutations

6

Describe what happens in gene duplication and divergence

both copies remain functional while diverging in sequence and pattern of expression

7

Name this DNA-binding motif:
simplest; two alpha helices connected by short chain of amino acids that make the turn at a fixed angle; longer helix portion = recognition module

helix-turn-helix

8

Name this DNA binding motif:
includes Zn atom; amino acid sequence drawn out looks like finger; binds to major groove

zinc finger domain

9

Name this DNA binding motif:
two alpha helical DNA binding domain; dimerizes through leucine zipper region; interactions between hydrophobic amino acid side chains at every 7 amino acids down one side of alpha helix: forms zipper structure; grabs DNA like clothespin

leucine zipper motif

10

Name this DNA binding motif:
consists of a short alpha chain connected by a loop to a second larger alpha chain; can occur as homodimers or heterodimers; three domains: DNA binding domain, dimerization domain, activation domain

helix-loop-helix

11

Describe regulation by RNA stability (2 things)

1 - decapping: exposed mRNA degraded from 5' end
2 - mRNA degraded from 3' end through poly-A tail and into coding region

12

____ ___ modifications are required by proteins to be functional

post translational

13

An apparatus that deliberately destroys aberrant protein is called what?

proteasome

14

In regards to specificity of protein degradation, there is one E1 ubiquitin activating enzyme and 1 proteasome but 30 E2 ubiquitin conjugating enzymes and hundreds of E3 accessory proteins. True or false?

true

15

Explain methylation and genomic imprinting

what genes get expressed (or not) from mom and dad

16

X-chromosome inactivation

even things out XX vs. XY - 2 X chromosomes vs 1 X chromosome

17

What are the 3 major transition checkpoints of the cell cycle

start: G1 to S
G2 to M
In M phase: anaphase and cytokinesis

18

True or false? activites of Cdks rise and fall during the cell cycle

true

19

Cdks are dependent on what proteins

cyclins

20

Without cyclin bound (inactive state) the active site of Cdk is blocked by a region of the protein called the __ ___

T loop

21

Phosphorylation of Cdk at T-loop fully activates enzyme. T or F?

true

22

What phosphorylates Cdk?

CAK

23

Name the effects of Wee1 and Cdc25 on Cdk-cyclin activities

Wee1: inactivates Cdk-cyclin by phosphorylation

Cdc25: removes phosphorylation, thus activating Cdk-cyclin

24

The 2 step process of chromosome condensation and resolution is brought about by what?

condensin

25

M-Cdk activates ____ to complete mitosis

APC/C

26

Chromosomes are attached to microtubules at the ____

kinetochore

27

Name the three forces that move chromosomes to opposite pole

1: depolymerization: major force pulls the kinetochore and chromosome toward the spindle pole. depolymerization of the plus end of the microtubule drives the pulling of the kinetochore poleward
2. microtubule flux: microtubules are moved toward spindle poles while being dismantled at minus end. tubular added at plus end while being removed at minus end
3. polar ejection force: kinesin-4, 10 motors on chromosomes interact with microtubules and transport chromosome from poles. results in push-pull phenomenon

28

Describe the intrinsic pathway of apoptosis

when cytochrome c is released from mitochondria, it binds to a protein called Apaf1 and forms apoptosome

29

What is the role of BH123 in apoptosis?

BH 123 proteins become activated, form aggregation in mitochondrial outer membrane and induce release of cytochrome c - then apoptosome formed

30

Bcl2 proteins regulate intrinsic apoptosis. true or false?

true

note: Bcl2 is an anti-apoptotic protein