BSCI330 Final Exam

Question 1

4 components of extracellular matrix

Answer 1

Collagens
Proteoglycans
Fibronectins
Laminins

Question 2

Order of inhibiting CDK

Answer 2

ATM, Chk2, p53, p21, inhibit CDK

Question 3

How to break down nuclear envelope

Answer 3

Phosphorylate nuclear proteins which can help compact chromosomes

Phosphorylation of nuclear lamina leads to envelope disassembly

Question 4

MPF Proteins

Answer 4

Cyclins

Cyclin dependent kinases

Question 5

How to fibroblasts crawl

Answer 5

Actin is made at the lamellipodium and degraded at the back end

Question 6

Drugs for microtubules

Answer 6

Nocodazole breaks down microtubules

Taxol keeps them from breaking down

Question 7

Drugs for microfilaments

Answer 7

Cytochalasin breaks down microfilaments

Phalloidin keeps them from breaking down

Question 8

What is the name of the calcium receptor in the smooth ER

Answer 8

Ryanodine receptor

Question 9

Components of insulin signaling pathway

Answer 9

RTK receptor that dimerizes and phosphorylates IRS and ultimately PLG gamma

Question 10

What does a Ras mutation do

Answer 10

Keeps GTP bound to Ras which keeps cell growing and dividing

Question 11

What are the motor proteins for microtubules and which way to they go

Answer 11

Kinesin - to +

Dynein + to -

Question 12

What make up microtubules and microfilaments? Which uses ATP and which uses GTP?

Answer 12

Alpha and beta tubulin make microtubules - uses GTP

G-actin makes up microfilaments - uses ATP

Question 13

What are the 2 common MTOC’s?

Answer 13

Centrosomes and basal bodies

Question 14

What makes ECM gel-like?

Answer 14

Proteoglycans

Question 15

What are three generally properties of all catalysts?

Answer 15

Not altered by reaction
Only need small amounts
Catalyze forward and reverse reactions equally

Question 16

Name 2 ways proteins can be immobilized in a membrane

Answer 16

Tethered by other proteins outside the cell

Tethered to cytoskeleton

Question 17

Name 2 functions of glycolipids in plasma membrane

Answer 17

Protection of membrane
Function as signaling molecule
Function as substrate for enzyme in cell

Question 18

Transport protein in apical membrane of gut epithelial cell that is not in basal membrane

Answer 18

Na-glucose transporter

Question 19

What is the difference between a P type pump and a V type pump

Answer 19

A P type pump has a high energy phosphorylated intermediate using a P from ATP

A V type pump drives H+ ions against their concentration gradient and does not use a Pi

Question 20

Example of medical application of ABC transporter

Answer 20

ABC transporters pump lipophilic substances out of cells and anti-cancer drugs get delivered in lipophilic vesicles are are pumped out because overactive transporters

Question 21

Nernst equation

Answer 21

deltaV = (RT/zF) ln[out]/[in]

Question 22

Equation for delta G

Answer 22

Delta G = RTlnKeq + delta G zero

Question 23

Why do we do fermentation if lactate and ethanol are toxic?

Answer 23

To regenerate NAD+

Question 24

What is the rule for how small you can resolve with light microscopy

Answer 24

wavelength of light over 2

Question 25

What does confocal microscopy measure?

Answer 25

Fluorescence

Question 26

What 2 tags would you want for FRET?

Answer 26

Absorb blue emit green | Absorb green emit red

Question 27

In nuclear transport what is the concentration gradient

Answer 27

High GTP inside | High GDP outside

Question 28

What is the name of the pore in translation into the ER

Answer 28

Translocon

Question 29

What happens to misfiled proteins in the ER

Answer 29

Calnexin recognizes, ubiquitin binds to it and then exported and degraded by proteasome

Question 30

What do Rab and Sar do?

Answer 30

Rab - docking and tethering of vesicle to destination | Sar - helps initiate vesicle coat assembly and stability

Question 31

What coat targets ER to Golgi

Answer 31

COPII

Question 32

Signal displayed by proteases in golgi to sort them into vesicles bound for lysosomes?

Answer 32

M-6-P

Question 33

How does a steroid hormone enter a cell and regulate gene transcription

Answer 33

Enter cell and nucleus and bind to steroid hormone receptor which kicks of an inhibitory protein and activate another protein on the receptor which will bind to DNA and start transcription

Question 34

Phosphoinositide cascade

Answer 34

Gq, PLC beta, split PIP2 into DAG and IP3 DAG in membrane and activated PKC IP3 to smooth ER

Question 35

Liver epinephrine cascade

Answer 35

beta-adrenergic receptor, G-protein, adenylate cyclase, cAMP, PKA phosphorylase kinase glycogen synthase CREB

Question 36

How does an action potential travel down a skeletal muscle cell cause a release of calcium ions?

Answer 36

Action potential travels down t-tublue and calcium gated ion channels open and then ryanodine receptors often and calcium is released from the sarcoplasmic reticulum

Question 37

How does cytoplasmic streaming work?

Answer 37

Actin filaments and myosin motor proteins are involved. Myosin is attached to the cytoplasm across the inner surface of the membrane. There is one head so it can hop.

Question 38

Why might the total concentration of an M-cyclin in a cell be high but mitosis might not be triggered?

Answer 38

Cyclin has to be properly phosphorylated to be activated

Question 39

How can adhesion of a cell to a substrate result in the transcription of new genes?

Answer 39

The conformational change in the integrin upon binding the protein ligand is passed on via the cytoskeleton to a chain of protein kinases which ends up phosphorylating transcription factors allowing expression of genes

Question 40

What makes something a steady state?

Answer 40

If it consumes energy

Question 41

How do you get a protein out of a membrane?

Answer 41

Detergents

Question 42

Why aren't intermediate filaments polarized?

Answer 42

They first assemble into polarized dimers but the dimers assemble head to tail