biochem random

Question 1

is heterochromatin or euchromatin transcriptionally active?

Answer 1

euchromatin

Question 2

histone acetylation does what to DNA? active or inactive?

Answer 2

makes it ACTIVE by relaxing DNA coiling

Question 3

AA required for purine synthesis

Answer 3

Glycine, Aspartate, Glutamine

Question 4

rate limiting enzyme of pyrimidine synthesis

Answer 4

carbamoyl phosphate synthetase II

Question 5

what is a prodrug of 6MP used to inhibit de novo purine syntesis

Answer 5

azathioprine

Question 6

what drug inhibits ribonucleotide reductase?

Answer 6

hydroxyurea

Question 7

what drug inhibits thymidylate synthase?

Answer 7

5-FU

Question 8

primase makes a _____primer on which DNA polymerase____ can initiate replication

Answer 8

RNA primer; DNA polymerase III

Question 9

which DNA polymerase has 5-3’ exonuclease?

Answer 9

DNA polymerase I

Question 10

telomerase is a RNA-dependent DNA polymerase that adds DNA to which end of chromosome? why?

Answer 10

3’ end; to prevent loss of genetic material

Question 11

sickle cell results from what type of DNA mutation?

Answer 11

missense mutation

Question 12

what type of DNA repair results in double stranded breaks?

Answer 12

nonhomologous end joining

Question 13

what dz is d/t defective nonhomologous end joining

Answer 13

ataxia telangiectasia

Question 14

mutation of helicase, defective DNA replication and repair, presents w/ immunodeficiency, incr sensitivity to UV light, incr susceptibility to cancer, infertiility

Answer 14

Bloom syndrome

Question 15

which RNA polymerase makes each of the following?
rRNA
mRNA
tRNA

Answer 15

rRNA - poly 1
mRNA - poly2
tRNA - poly3

Question 16

what are the 3 stop codons?

Answer 16

UGA, UAA, UAG

Question 17

what must happen to RNA before it is transported out of the nucleus (3 things)

Answer 17

1. 5’cap
2. polyadenylation of 3’ end
3. splicing out of introns

Question 18

where does mRNA quality control occur?

Answer 18

cytoplasmic P bodies

Question 19

aminoacyl tRNA synthetase works at what end?

Answer 19

3’ end

Question 20

one gene contributes to multiple phenotypic efffects

Answer 20

pleiotropy

ie. PKU

Question 21

mutations at different loci can produce a similar phenotype

Answer 21

locus heterogeneity

ie. albinism

Question 22

prader willi and angelman syndromes are d/t deletion of genes on what chromosome

Answer 22

chromosome 15

Question 23

what normally inhibits G1 ro S phase progression

Answer 23

p53

hypophosphorylated Rb

Question 24

RER in neurons is called what?

Answer 24

nissl bodies

Question 25

what types of cells are rich in smooth ER?

Answer 25

liver hepatocytes, adrenal cortex, gonads

Question 26

coarse facial features, clouded cornea, restricted joint movement, high plasma levels of lysosomal enzymes

Answer 26

I cell disease | deficiency mannose 6P on GP

Question 27

accumulation of very long chain FA in tissue; inability to form myelin

Answer 27

zellweger syndrome, d/t defect in peroxisomes

Question 28

vimentin is a structural component of______

Answer 28

connective tissue

Question 29

nuclear lamins are a structural component of______

Answer 29

nuclear envelope and DNA within

Question 30

defect in procollagen peptidase

Answer 30

ehlers danlos (issue with croslinking to make collagen fibrils)

Question 31

defect in glycosylation of collagen, not enough collagen type 1

Answer 31

osteogenesis imperfecta

Question 32

CT dz caused by impaired Cu absorption and transport, decr activity of lysyl oxidase; presents with brittle, kinky hair, hypotonia

Answer 32

Menkes disease

Question 33

defect in fibrillin

Answer 33

Marfan

Question 34

sites of gluconeogenesis

Answer 34

liver kidney intestinal epithelium

Question 35

what is released to signal need to break down glycogen?

Answer 35

1. glucagon | 2. epinephrine

Question 36

cardiomyopathy, hyporeflexia, progressive muscle weakness, defect in lysosomal alpha 1,4 glucosidase

Answer 36

Pompe disease

Question 37

defective debranching enzyme (alpha 1,6 glucosidase)

Answer 37

Cori disease (more mild form of Von Gierke dz)

Question 38

which dz can be supplemented with high intake of ketogenic nutrients (lysine and leucine)

Answer 38

PDH complex deficiency

Question 39

neuro defects, lactic acidosis, incr serum alanine starting in infancy

Answer 39

PDH complex deficiency

Question 40

which B vitamins are req'd to make PDH complex or alpha KGDH complex?

Answer 40

B1, B2, B3, B5

Question 41

what are the 2 main nitrogen transporters in teh blood

Answer 41

1. alanine | 2. glutamine

Question 42

what are 3 ETC uncoupling agents

Answer 42

1. ASA 2. 2,4 DNP 3. thermogenin

Question 43

skin lesions, edema, fatty liver, anemia, depigmented skin and hair

Answer 43

kwashiorkor (protein malnutrition)

Question 44

primary nrg source of a person who has not eaten in 2 days

Answer 44

FA

Question 45

x linked recessive, incr orotic acid in blood/urine, hyperammonia, decr BUN - defect in?

Answer 45

ornithine transcarbamylase deficiency

Question 46

intellectual disability, osteoporosis, tall stature, kyphosis, lens subluxation, thrombosis, atherosclerosis, marfanoid habitus

Answer 46

homocystinuria

Question 47

hereditary defect of renal PCT and aa transporter for COLA (cysteine, ornithine, lysine, arginine)

Answer 47

cystinuria | tx: urinary alkanization

Question 48

MSUD is d/t deficiency in what?

Answer 48

branched chain alpha KGD complex

Question 49

which vitamin excess can lead to incr ICP?

Answer 49

vitamin A

Question 50

dehydrogenase rxns require what vitamin? component of FAD and FMN also

Answer 50

vitamin B2 (riboflavin)

Question 51

which vitamin is a constituent of NAD and NADP

Answer 51

vitamin B3 (niacin)

Question 52

a patient presents with convulsions and irritabiltiy - what vitamin deficiency is indicated?

Answer 52

vitamin B6

Question 53

used by pyr dehydrogenase and alpha KG dehydrogenase

Answer 53

vitamin B1

Question 54

deficiency that can be cause by isonizid use

Answer 54

B6 (pyridoxine) | B3 (niacin)