Biochemistry

Question 1

Purines and Pyrimidines

Answer 1

PURe As Gold (Adenine , Guanine)

CUT the PY (Cytosine, Uracil, Thymine)

Question 2

Thymine Structure

Answer 2

THYmine has a meTHYl (compared to Uracil)

Question 3

Nucleoside vs Nucleotide

Answer 3

NucleoSide = base + deoxyribose (Sugar)
NucleoTide = base + deoxyribose + phosphaTe

Question 4

AA for Purine Synthesis

Answer 4

GAG: Glycine, Aspartate, Glutamine

Question 5

Histone Methylation

Answer 5

Histone Methylation Mostly Makes DNA Mute

Question 6

Histone Acetylation

Answer 6

Histone Acetylation makes DNA Active

Question 7

DNA Methylation

Answer 7

CpG Methylation Makes DNA Mute

Question 8

Lesch-Nyhan Syndrome

Answer 8

Defective purine salvage due to absent HGPRT:
Hyperuricemia
Gout
Pissed off (aggression, self-mutilation)
Retardation
DysTonia

Question 9

Nonsense DNA Mutation

Answer 9

Stop the nonsense! (nucleotide substitution resulting in early stop codon)

Question 10

mRNA start codons

Answer 10

AUG inAUGurates protein synthesis

Question 11

mRNA stop codons

Answer 11

UGA = U Go Away
UAA = U Are Away
UAG = U Are Gone

Question 12

Introns vs Exons

Answer 12

Introns are Intervening sequences and stay In the nucleus, whereas Exons Exit and are Expressed

Question 13

tRNA Structure

Answer 13

AA is covalently bound to 3’ end (aminoacyl end, CCA) of tRNA. CCA Can Carry Amino acids

Question 14

Protein Synthesis Initiation

Answer 14

Eukaryotes: 40S + 60S –> 80S (Even)
PrOkaryotes: 30S + 50S –> 70S (Odd)
ATP: tRNA Activation (charging)
GTP: tRNA Gripping and Going places (translocation)

Question 15

Protein Synthesis Elongation

Answer 15

Going “APE”:
A site = incoming Aminoacyl-tRNA
P site = accomodates growing Peptide
E site = holds Empty tRNA as it Exits