Kaplan FL1

Question 1

what does a retrovirus do with RNA

Answer 1

A retrovirus is a virus that uses RNA as its genomic material. Upon infection with a retrovirus, a cell converts the retroviral RNA into DNA, which in turn is inserted into the DNA of the host cell. The cell then produces more retroviruses, which infect other cells.

Question 2

muscle contraction depends on

Answer 2

release of calcium not sodium from sarcoplasmic reticulum

Question 3

role of espophagus

Answer 3

transport
not huge role in absorption of nutrients

Question 4

autonomic vs volunary control in digestive system

Answer 4

swallowing - voluntary
contraction of 2/3 bottom esophagus and remainder of canal - autonomic

Question 5

upon contraction of muscle cells in esophagus what happens?

Answer 5

esophagus longitudinal layer shortens

Question 6

conversion between glucose and galactose is what process?

Answer 6

epimerization

Question 7

what decreases membraine fluidity

Answer 7

• saturated fatty acids (single) have no large kinds, pack tightly and decreaase fluidity
• ## many lipid rafts (microdomans of cholsterol and sphingolipids)

Question 8

what increases membrane fluidity

Answer 8

• unsaturated fatty acids (double) increases fluidity as the kinds in the fatty acid taisl push them farther apart
• decreasing lipid rafs

Question 9

how do phosphatidylcholines affect membrane fluidity

Answer 9

not really affect

Question 10

if a PPP makes NADP which reduces gluthaion disulfide and protects RBCs from ROS, then a deficiency in NADPH would result in

Answer 10

increased oxidation
damage to RBCs

Question 11

depolarization vs repolarizationv vs hyperpolarization of neuron

Answer 11

depolarization - less neg charge, increases mem pot from -70 to -55 (threshold / AP level) as Na_ move in

Na+ channels close, K+ channels open

repolarization - more ng charge, decreases mem potential as K+ moves in

hyperpolarization - when repolarization makes cell membrane more neg than resting mem potential

Question 12

hypopolarization

Answer 12

initial increase in mem pot with influx of Na+ prior to hitting threshold

NOT hyperpolarization (peroid of repolarization below resting potential)

Question 13

convert C to K

Answer 13

c + 273 = deg K

Question 14

osmotic pressure

Answer 14

Question 15

opiod receptors are what kind of receptors made in the

Answer 15

transmembrane protein receptors

made in ER

proteins that will be secreted by cell or targeted to membrane such as plasma membrane are made by ribosomes attached to R
(while many others are made by ribosome in cytoplasm)

Question 16

what does a V276I substitution mean?

Answer 16

it means V –> I
valine –> isoleucine at position 276

Question 17

what amino acid substitutions are least likely to impact protein function?

Answer 17

substituiting within same group
same polarity
same size

Question 18

What happens at the 1 cell stage of development

Answer 18

Cell divides into 2 totipotent cells
Which could be a separate organism each and are undifferentiated until 16 cell stage

Question 19

What happens at the 16 cell stage of development

Answer 19

Cells form the morula and begin to differentiate

Question 20

What happens after the morula stage?

Answer 20

Blastulation is the hollowing of the morula which differentiates into the inner cell mass giving rise to the organism and the trophoblast which becomes the extra embryonic tissue like the placenta

Question 21

What happens after blastulation?

Answer 21

The blastula divides into 3 germ layers for gastrulation: mesoderm, endoderm, ectoderm

Question 22

A patient diagnosed with stenosis of the mitral valve would experience the greatest increase in blood pressure in his:

Answer 22

The mitral valve sits between the left atrium and the left ventricle, preventing backflow of blood into the left atrium. Since, with stenosis, the size of the opening for the valve is decreased, there will be less blood pumped through that valve. In the case of this individual, that means that blood flow from the left atrium to the left ventricle will be impeded, resulting in increased blood volume, and therefore increased blood pressure, in the left atrium

Question 23

valves of the heart

Answer 23

tricuspid - between right atrium and right ventricle

mitral - between left atrium and left ventricle

aortic - between left ventricle and aorta

pulmonary - between right ventricle and pulmonary artery

Question 24

what is stenosis?

Answer 24

Stenosis (or narrowing of the valve). When the valve(s) opening becomes narrowed, it limits the flow of blood out of the ventricles or atria. The heart is forced to pump blood with increased force to move blood through the narrowed or stiff (stenotic) valve(s).

Question 25

ways that bacteria regulate gene expression

• DNA methylation
• cytoplasmic receptors
• plasma membrane receptors
• histone methylation

Answer 25

True: DNA methylation
- cytoplasmic receptors
- plasma membrane receptors
- histone methylation

FALSE: histone methylation – no histones in bacteria

Question 26

hypermethylation is associated with

Answer 26

gene inactivation

Question 27

if a condition is inherited sporadically whats the gene expression of the parents

Answer 27

they would have normal expression