Biochem Stuff

Question 1

DNA methylation at _________ represses transcription

Answer 1

CpG islands

Question 2

Leflunomide MOA?

Answer 2

inhibits dihydroorate dehydrogenase. Disrupt pyrimidine synthesis.

Question 3

MTX, TMP, and Pyrimethamine MOA?

Answer 3

Inhibits dihydrofolate reductase. Disrupt pyrimidine synthesis.

Question 4

5-FU MOA?

Answer 4

forms 5-F-DUMP which inhibits thymidylate synthase. Disrupt pyrimidine synthesis.

Question 5

6MP MOA?

Answer 5

inhibit de novo purine synthesis

Question 6

Mycophenylate and Ribavarin, MOA?

Answer 6

inhibit inosine monophosphate dyhdrogenase. Disrupt purine synthesis

Question 7

Hydroxyurea MOA?

Answer 7

Disrupt pyrimidine and purine synthesis. Inhibits ribonucleotide reductase.

Question 8

What does HGPRT due? What disease is the absence of this?

Answer 8

Converts hypoxathine to IMP and guanine to GMP. Lesch Nyhan syndrome. You get excessive uric acid production.

Question 9

What prevents the DNA strand from reanealing in replication?

Answer 9

DNA binding proteins

Question 10

What makes an RNA primer for DNA pol III to initiate replication?

Answer 10

Primase

Question 11

What’s special about DNA pol III?

Answer 11

Prokaryotic only. Has 5’-3’ synthesis and proofreads with 3’-5’ exonuclease

Question 12

What’s special about DNA pol I?

Answer 12

Prokaryotic only. Same function as pol 3, but will also degrade/ excise the RNA primer with exonuclease.

Question 13

DNA ligase?

Answer 13

Joins Okazaki fragments

Question 14

Adds DNA to 3’ ends to avoid loss of genetic material. Eurkaryotes only.

Answer 14

Telomerase

Question 15

In E. Coli… if low glucose, but lactose is available. What happens?

Answer 15

Lac Operon is activated. and there is a shift to lactose metabolism.

Question 16

What’s defective in Lynch Syndrome

Answer 16

Mismatch Repair - (mismatched nucleotides are not fixed) G2 phase

Question 17

What’s defective in Xeroderma Pigmentosum?

Answer 17

Nucleotide Excision Repair. (Pyrimidine dimers (thiamine dimers), are not reparied). G1 phase

Question 18

Important in repair of spontaneous/toxic deamination?

Answer 18

Base excision repair

Question 19

RNA Pol 1 makes?

Answer 19

rRNA

Question 20

RNA Pol 2 makes?

Answer 20

mRNA

Question 21

RNA Pol 3 makes?

Answer 21

tRNA

Question 22

Stretch of DNA that alters gene expression by binding transcription factors

Answer 22

Enhancers

Question 23

Site where negative repressors/ regulators bind

Answer 23

Silcencers

Question 24

p53 inhibits?

Answer 24

Cyclin Dependent Kinases (CKDs) which phosphorylate proteins to continue cell cycle progression

Question 25

Hereditary motor and sensory neuropathy (HMSN). Defective production of proteins involved in the structure and function of peripheral nerves or myelin sheaths. AD and ass/ w/ foot deformities, LE weakness and sensory issues.

Answer 25

Charcot Marie Tooth. (Foot in Mouth disease)

Question 26

Rapid dementia with Clonus

Answer 26

Creutzfeldt Jakob

Question 27

Acute demyelination of CNS. Destruction of Oligodendrocytes. Will see this with HIV and JC virus.

Answer 27

Progressive multifocal Leukoencephalopathy

Question 28

Cafe au lait spots, Lisch Nodules, Neurofibromas, optic gliomas, pheochryomocytomas. Diagnosis, What's mutated, and what Chromosome?

Answer 28

Neurofivromatosis type 1 (von recklinhausen), NF1 tumor gene (RAS), and Chromosome 17

Question 29

Site of steroid synthesis

Answer 29

SER

Question 30

Site of secretory (exported) protein, and N-Linked olligosaccharide addition to proteins

Answer 30

RER

Question 31

Course Face, clouded corea, restricted joint movement, and high levels of lysosomal enzymes. Fatal

Answer 31

I cell disease

Question 32

defect in N-acetylglucosaminyl-1-phosphotransferase. Golgi can't phosphorylate mannose residue on glycoproteins

Answer 32

I-Cell disease

Question 33

Rate Limiting Enzyme of Glycolysis

Answer 33

Phophofructokinase-1 (converts F6P to F16BP)

Question 34

FBPase-2 and PFK-2 are the same bifunctional enzyme who's function is reversed by?

Answer 34

Phosphoyrlation of Protein Kinase A

Question 35

PFK-2 activation means

Answer 35

(Fed State) lets run glycolysis and store some stuff.

Question 36

FBPase-2 activation means

Answer 36

Fasting state. Lets run gluconeogenesis

Question 37

Buildup of pyruvate that gest shunted to lactate and alanine. X-linked

Answer 37

Pyruvate Dehydrogenase Complex Deficiency

Question 38

Neuro defects, lactic acidosis, and increased alanine at infancy

Answer 38

Pyruvate Dehydrogenase Complex Deficiency. Tx increase lysine and leucine intake

Question 39

What converts alpha-ketoglutarate to succinyl coA?

Answer 39

Alpha-Ketoglutarate Dehydrogenase (similar cofactors as pyruvate dehydrogenase complex)

Question 40

Rotenone inhibits

Answer 40

complex 1

Question 41

How does NADH E- from clycolysis enter mitochondria?

Answer 41

Via malatp-aspartate or glycerol 3 phosphate shuttle

Question 42

Cyanide and CO inhibit complex?

Answer 42

4

Question 43

Uncoupling agents for e- transport chain

Answer 43

Brown fat, 2,4-Dinitrophenol

Question 44

Pyruvate carboxylase requires_______________ to convert pyruvate to oxaloacetate?

Answer 44

Biotin

Question 45

G6P convergs NADP to NADPH via?

Answer 45

G6PDehydrogenase

Question 46

No in NADPH in RBC leading to hemolytic anemia

Answer 46

G6PD deficiency