Snapps week 1

Question 1

if a cell shrinks, the solution is

Answer 1

hypotonic

Question 2

internal virion proteins are coded by which gene

Answer 2

gag

Question 3

pol encodes from

Answer 3

reverse polymerase

Question 4

v-myc mimics

Answer 4

c-myc proto-oncogene in cell growth and division

Question 5

total outside cells included

Answer 5

ECF AND 5th space for a total of 18L

Question 6

p53 mutations are most often

Answer 6

missense

Question 7

which substances will not dissociate in solution?

Answer 7

(NH2)2 CO
Urea
Glucose

Question 8

what drug target to prevent refolding of SNARE

Answer 8

sec1

Question 9

sec1 functions to

Answer 9

refold SNAREs into their active conformation by binding and acting on syntaxin

Question 10

aldosteone acts on the ____, it increases ___

Answer 10

collecting tubule

K excretion

Question 11

aldosterone is low in ____

Answer 11

diabetics

Question 12

aldosterone is decreased by

Answer 12

ACE inhibitors and ARBs

Question 13

95% of p53 mutations are caused by

Answer 13

inhibiting transactivation binding domain, so p53 can’t bind DNA

Question 14

too many anti-acids can cause

Answer 14

Low pH facilitates of passive diffusion of plasma across the mucosal barrier

Question 15

what always moves passively across membrane?

Answer 15

urea and water

Question 16

FAP is ___ inherited

Answer 16

dominant

Question 17

manifestations of VHL

Answer 17

1. large vascular cell carcinomas
2. angiomatosis retinae
3. hemangiomas

Question 18

which hyperkalemia treatment stimulates uptake of extracellular potassium into cells?

Answer 18

insulin and glucose

Question 19

HPV function to stim cancer

Answer 19

inhibits p53 and RB

Question 20

if cell vm= -40, concentration of Naout =140

Na in= 14

Answer 20

Na is being pumped into the cell because
vm= -40
E = log (140/14) = +60

Question 21

A cell in a steady state contains 200mM of a neutral nonpermeating protein. The cell membrane is impermeable to Na+ but permeable to Cl-. If there is 200mM Na in the ECF, what is the total osmolarity, Na+ and Cl- concentrations inside the cell?

Answer 21

total osmolarity: 200
Na = 200
cl= 0

Question 22

As a result of ketoacidosis, blood HCO3- concentration is reduced from 24 to 8mM. Hyperventilation causes pCO2 to drop to 15mmHg. What is the patient’s blood pH?

Answer 22

7. 3 pH = 6.1 + log (8mM)/(.03x15) =

7. 34

Question 23

A cell containing only water and 300mM of a non-permeating protein is placed in a solution of 600 non-permeating sucrose. The membrane is permeable to water. What will be the volume of the cell (relative to its initial volume) after all net fluxes have stopped?

Answer 23

cell will be 1/2 its initial volume

the cell will shrink to 1/2 its initial volume, at which point the osmolarity inside will equal the osmolarity outside, which is another way of saying that the concentration of water on the two sides is the same

Question 24

SNAPs and syntax ins are located?

Answer 24

target membrane

Question 25

An 8 year old boy presents to your office for increased work of breathing. His parents explain that he has been complaining of increased thirst and urination for the past 3 weeks. He has lost 8 pounds since his last visit and his breath smells slightly fruity. After doing initial blood work, you find a venous pH of 7.04. You proceed with a urine analysis. Which of the following findings is most likely?

Answer 25

increased K+ The increased levels of H+ will be cause H+ to be exchanged for K+

Question 26

VHL inheritance

Answer 26

autosomal recessive

Question 27

most serious symptoms of hypokalemia?

Answer 27

``` cardiac arrhythmia also Low BP high HR decreased appetite diarrhea low K ```

Question 28

common to all SNARE protein

Answer 28

helical domain

Question 29

most common cause of death in VHL patients today?

Answer 29

renal cell carcinoma

Question 30

What results from insulin release from pancreatic B cells?

Answer 30

1. increased storage of glycogen in liver 2. decrease in lipolysis and gluconeogeneisis in liver 3. inhibits ketone body formation 4. increases fatty acid storage as triglycerides 5. signals cellular uptake of glucose

Question 31

A soldier is stranded and starving in the desert. Because of his starvation, he has become less capable of producing ATP. As a result his Na+/K+ transporter is affected. Which of the following effects would a compromised Na+/K+ pump have on his cells?

Answer 31

resting membrane potential moves toward sodium equilibrium potential

Question 32

If a cell is a steady state has a Vm = -80 mV, and the concentration of H+ out = 50 nM, and H+ in = 100 nM, Which of the following must be true?

Answer 32

H is being pumped into the cell | Vm = -80 mV E = 60log (50/100) = -18 mV

Question 33

Which of the following drugs have been shown to DECREASE serum K?

Answer 33

loop diuretics

Question 34

how diuretics work?

Answer 34

diuretics increase excretion, so would decrease K ACE inhibitors and ARB (Retinoblastoma)s, NSAIDS, heparin, and drugs that contain K will increase blood potassium Dietary K also contributes

Question 35

A cell that is homozygous for mutated RB (Retinoblastoma gene) is in S phase of the cell cycle. If a signal from outside the cell arrives to the plasma membrane in order to trigger inhibition of cell growth, which of the following will occur?

Answer 35

cell continues to divide because RB cannot be activated and inhibit cell growth

Question 36

increased risk for cerebral edema are:

Answer 36

1. administer bicarbonate quickly 2. insulin quickly 3. smaller than normal increase in Na

Question 37

which would make hyperkalemia a more serious problem in a patient?

Answer 37

neuropathy

Question 38

inheritance of RB?

Answer 38

autosomal recessive (because it requires 2 hits) with a dominant inheritance pattern (a single LOH will cause cancer)

Question 39

If O2 level decrease, Hif1 alpha will _____

Answer 39

not be ubiquitinated and will promote vascularization.

Question 40

in the presence of high CDK,

Answer 40

more cells will proceed into S phase

Question 41

function of NSF?

Answer 41

hydrolysis of ATP to disassemble SNARe complex

Question 42

A patient presents to your clinic with hyperkalemia caused by rhabdomyolysis. Why are you concerned about decreased kidney function?

Answer 42

myoglobin is toxic to kidneys

Question 43

Suppose we have a cell that is permeable to Cl-, with a higher concentration of Cl in the ECF than in the cell. What will be the sign of the Cl equilibrium potential?

Answer 43

negative a negative Ecl will be needed to repel C and keep it from diffusing into the cell down its concentration gradient

Question 44

A cell containing 300 mosM of non-permeating ions is placed into a solution containing only 300 mosM solute with a reflection coefficient of 0.5. What will happen to the cell?

Answer 44

it will swell eventually it will swell eventually. A reflection coefficient of .5 means that the solute can get into the cell half as easily as water. So at first, the ECF osmotic force = .5(600) = 300, and it will be isotonic. However, the solute will move into the cell and water will follow it. The cell will eventually swell and lyse.

Question 45

Sorafenib and sunitinib are drugs that target which of the following?

Answer 45

VEGF-Receptor and PDGF-Receptor

Question 46

A transporter in the proximal convoluted tubule of the kidney expels a bicaRB (Retinoblastoma)onate ion into the lumen of the tubule, while a chloride ion moves from the lumen into the cell. No ATP molecules are split in the process. Rather, energy from the downhill leak of sodium ions into the cell is what drives this transporter. Based on this information, you know this transporter must be which of the following?

Answer 46

exchanger

Question 47

What is the best explanation for the rationale behind slow administration of insulin?

Answer 47

avoid rapid cellular fluid uptake

Question 48

A cell sequesters amino acids in its cytoplasm via secondary active transport. What would happen to the concentration of amino acids if extracellular sodium is reduced so that Na inside the cell equals Na outside the cell?

Answer 48

net uptake of aa will stop

Question 49

If [A-]/[HA] = 2, what percentage of the solution is deprotonated?

Answer 49

66%

Question 50

During clysis, 300mosM glucose is administered subcutaneously to an infant. Why does a blister grow, but eventually disappear?

Answer 50

the reflection coefficient of glucose is greater than the reflection coefficient of NaCl.

Question 51

K redistribution can cause hyperkalemia because K shifts from the cells into the ECF. Which of the following will promote potassium reuptake into cells?

Answer 51

beta agonist

Question 52

venous blood is more ____ than arterial blood

Answer 52

acidic

Question 53

What is the osmolarity of a 35M solution of KCl?

Answer 53

70 osM 1K, 1Cl = 2osM/L x 35L = 70 osM

Question 54

``` If urea has a reflection coefficient of zero, what is the osmotic driving force for H20 to enter this cell? Na 100 (-) 100 Urea 100 (+) 0 Glucose 100 (-) 0 ```

Answer 54

100 mosM If the reflection coefficient for urea =0 then it does not exert any osmotic force. Thus, there is a 100 mosM difference between ECF and ICF and water will move into the cell with an osmotic driving force of 100 mosM

Question 55

A cell containing only water and 300mM of a non-permeating protein is placed in a solution of 300 mM non-permeating NaCl, and 600 permeating glycerol. The membrane is permeable to water. What will be the volume of the cell (relative to its initial volume) after all net fluxes have stopped?

Answer 55

cell will be 1/2 initial volume the cell will shrink to 1/2 its volume. 300 mM NaCl - 600 mosM solution of Na and Cl ions. You can ignore glycerol completely.

Question 56

If the RB (Retinoblastoma) protein is hypophosphorylated in a cell, what will happen?

Answer 56

cell will be arrested in G1 phase