BIOL 110 Final Review

Question 1

Actin filaments

Answer 1

Responsible for cell shape, cell movement, and cytokinesis. Assemble head-to-tail to create flexible polar filaments. Slow-growing minus end, fast-growing plus-end. (Treadmilling)

Question 2

Microtubules

Answer 2

Responsible for organelle position, vesicle transport, and chromosome segregation.
Made up of 2 tubulin subunits (heterodimer)
Alpha+beta (vertical bonding)

Question 3

Intermediate filaments

Answer 3

Responsible for mechanical cell strength
IFs depend on lateral bundling and twisting of coiled-coils (coiled-coil proteins interact via hydrophobic interactions)

Question 4

Dynamic Instability

Answer 4

Microtubules can grow or shrink rapidly (T-forms grows, D-form shrinks)

Question 5

Microtubule catastrophe

Answer 5

transition from growth to shrinkage

Question 6

Microtubule rescue

Answer 6

transition from shrinkage to growth

Question 7

Kinesin 4, 10

Answer 7

bind chromosome arms & walk towards the plus-end of interpolar microtubules, pushing the sister chromatid toward the metaphase plate –> facilitate alignment of chromosomes at the spindle equator

Question 8

Kinesin 5

Answer 8

bundles interpolar microtubules in a parallel array and drives spindle pole separation by sliding microtubules that are oriented in opposite directions. (bipolar motor protein)

Question 9

Kinesin 14

Answer 9

minus-end directed, interacts with interpolar MTs, decreases distance between centrosomes

Question 10

Dynein

Answer 10

minus-end directed, regulates the length of astral MTs

Question 11

Klp10A

Answer 11

A kinesin known to depolymerize microtubules which anchors itself to the spindle pole matrix and binds to minus ends of MTs. –> Klp10A then actively drives flux by disassembling MT minus ends.

Question 12

CAKs (Cdk-activating kinase)

Answer 12

Phosphorylates the cyclin-Cdk complex, which fully activates it

Question 13

CKIs (Cdk Inhibitory proteins)

Answer 13

Uses inhibitory phosphorylation to suppress Cdk activity
–> Binding of CKIs inactivates cyclin-Cdk complexes used in the control of G1/S and S-phase

Question 14

Mitogens

Answer 14

stimulate cell division primarily by triggering a wave of G1/S-Cdk activity

Question 15

Growth Factors

Answer 15

stimulate cell growth by promoting the synthesis of proteins and by inhibiting their degredation

Question 16

Nucleosome

Answer 16

Made up of 2 histones (octamer). DNA wraps around nucleosomes, packaging it and determining whether or not it is available for transcription.

Question 17

Cohesin

Answer 17

A 4-subunit protein complex that mediates cohesion between replicated sister chromatids (essential for chromosome segregation in dividing cells)

Question 18

Condensin

Answer 18

A 5-subunit protein complex which plays a role in stabilizing loops

Question 19

Centrosome

Answer 19

Made up of a pair of centrioles and pericentriolar material (consist of a mother & daughter centriole)

Question 20

Topologically associated domains

Answer 20

Stabilizing loops

Question 21

Kinetochore microtubules

Answer 21

attach each sister chromatid to the spindle pole (75% anchored at the centrosome)

Question 22

Interpolar Microtubules

Answer 22

hold the 2 halves of the spindle together (75% are NOT anchored at the centrosome)

Question 23

Astral microtubules

Answer 23

radiate out and help orient and stabilize the spindle using the cell membrane

Question 24

Biorientation

Answer 24

a microtubule from 1 centrosome attaches to “kinetochore A” while a microtubule from the other centrosome attaches to “kinetochore B” (how sister chromatids align properly in metaphase) –> creates tension across the microtubule-binding sites which triggers an increase in microtubule binding affinity

Question 25

Microtubule flux

Answer 25

the movement of spindle microtubules towards the spindle poles & the disassembly of the MT minus-ends

Question 26

Polar ejection forces

Answer 26

Push the part of the chromosome with the kinetochore away from the pole and move the part with the kinetochore towards the pole.

Question 27

Apoptosis

Answer 27

cells are destroyed from within and then eaten by other cells

Question 28

Necrosis

Answer 28

animal cells die in response to acute trauma or lack of blood flow

Question 29

Adherens junctions

Answer 29

connect actin filament bundle in one cell with that in the next cell

Question 30

Desmosomes

Answer 30

Connect intermediate filaments in one cell with that in the next cell

Question 31

Tight junctions

Answer 31

seal the gap between epithelial cells

Question 32

Integrins

Answer 32

the principal receptors used by animal cells to bind to the extracellular matrix. --> heterodimers and function as transmembrane linkers between the extracellular matrix and the actin cytoskeleton.