MCAT BIOCHEMISTRY

Question 1

phosphodiester bond

Answer 1

link sugar molecules in a polynucleotide

Question 2

peptide bond

Answer 2

btwn amino acids

Question 3

disulfide bond

Answer 3

covalent bond; thiol S-S

Question 4

pyrimidine

Answer 4

1 ring

Question 5

posttranslational modification of proteins (histone acetylation)

Answer 5

western blot

Question 6

oligiodendrocytes

Answer 6

cns support

Question 7

amino acids that can be phosphorylated

Answer 7

tyrosine (Y), serine (S), and threonine (T)

Question 8

choosing an antigen for vaccine

Answer 8

immunogenicity and toxicity are LEAST suitable

Question 9

aminoacyl transferase

Answer 9

transfer tRNA orig bound at A to P then to E

Question 10

noncompetive plot

Answer 10

x-axis lines intercept

Question 11

competitive plot

Answer 11

y-axis lines intercept

Question 12

RT-PCR

Answer 12

transcriptional reg (mRNA)

Question 13

quantitative PCR

Answer 13

measures levels of DNA

Question 14

native PAGE

Answer 14

separate molecules based on: electrophoretic mobility, relying on length, conformation, and charge

Question 15

gel filtration

Answer 15

size. large elute first

Question 16

ion exchange

Answer 16

charge

Question 17

isoelectric focusing

Answer 17

isoelectric point (pH)

Question 18

water, as a liquid solvent, does not appear

Answer 18

in equilibrium constant expression

Question 19

Na+/K+-ATPase pumps

Answer 19

Na+ and K+ against their conc; 3 Na+ out and 2 K+ in

Question 20

competitive inhib on km and vmax

Answer 20

incr km no change on vmax

Question 21

noncomp inhib on km and vmax

Answer 21

no change on km and decr vmax

Question 22

uncompet inhib on km and vmax

Answer 22

decr km and vmax

Question 23

mixed inhib on km and vmax

Answer 23

incr/decr km and decr vmax

Question 24

peptide bonds formed and broken by

Answer 24

formed via condensation (dehydration) and broken via hydrolysis

Question 25

ex of enantiomers

Answer 25

D and L glucose

Question 26

epimers

Answer 26

differ at 1 chiral carbon

Question 27

anomers

Answer 27

differ at the anomeric carbon

Question 28

centromeres

Answer 28

hold sister chromatids together until separated in anaphase in mitosis. High GC content

Question 29

nonsense

Answer 29

truncation

Question 30

missense

Answer 30

codon that codes for diff aa

Question 31

transcription steps

Answer 31

helicase/topo, RNA polymerase II binds TATA w/in promoter region

Question 32

foramen ovale

Answer 32

connects right and left atria

Question 33

ductus arteriosus

Answer 33

connects pulm artery to aorta

Question 34

ductus venousus

Answer 34

connects umbilical vein to inf vena cava

Question 35

law of independent assortment

Answer 35

9:3:3:1

Question 36

operon:

Answer 36

- structural genes = DNA that codes for protein - operator gene = repressor binding site - promoter gene = RNA pol 1st binding site

Question 37

transformation

Answer 37

from environ into genetic material (antibiotic resist)

Question 38

conjugation

Answer 38

sex pili (male)

Question 39

transduction

Answer 39

bacteriophage acquires genetic info from host

Question 40

z/e stereochem

Answer 40

double bonds

Question 41

keq = 1

Answer 41

deltaG is 0; no ATP produced/rqd

Question 42

keq > 1

Answer 42

spontaneous