2013 biochem midterm

Question 1

What defines the target sequence of PCR technique?
A. Primers
B. dNTP
C. Pentose sugar moieties

Answer 1

A. Primers

Question 2

What prevents proteins from denaturation when we have fever?
a- Chaperons 
b- Kinase
c- Protease
d. Phosphotase

Answer 2

a- Chaperons

Question 3

What causes pyrimidine dimers in DNA?
A. Alkylation
B. Ionic radiation 
C. Deamination 
D. UV radiation

Answer 3

D. UV radiation

Question 4

How may hormones act through stimulation of protein kinases?
A- rapid increase in activity change in key enzymes
B- rapid decrease in protein degradation
C- rapid increase in suppression of key enzymes
D- rapid increase of glycosylation of key enzymes

Answer 4

?

Question 5

What is the most common sequence on human genome?
A- CGG  nucleotide repeats
B- centromeric repeats
C- Alu family
D- coding DNA sequence
E- pseudogenes sequence

Answer 5

C- Alu family

Question 6

what is the most abundant protein in the human body?
A- elastin
B- albumin
C- collagen

Answer 6

C- collagen

Question 7

What does histone acetylase cause in the nucleus?
A- gene induction 
B- gene splicing 
C- RNA editing
D- gene modification

Answer 7

A- gene induction

Question 8

What bond remains intact in albumin of the egg while boiling it
A- peptide bond
B- H bond
C- S-S bond
D- electrostatic bond

Answer 8

A- peptide bond

Question 9

Which of these is needed for making a beta turn?
A- lysine
B- Serine
C- Proline
D-Argnine

Answer 9

C- Proline

Question 10

What causes the activation of the RAS proto-oncogene?
A- Point mutation
B- Viral insertion
C- Chromosomal translocation
D- Deletion mutation

Answer 10

A- Point mutation

Question 11

Which enzyme recognizes correctly folded proteins and carry on glucose moiety?
A.glucokainse 
B.glucosidase I 
C. glucisidase II
D. Glocucyl-1-transferase

Answer 11

C. glucisidase II

Question 12

what happens to p53 tumor repressor in cancer?
a-activated
b-Increase in number 
c-mutated
d-phosphorylated 
e-translocated

Answer 12

c-mutated

Question 13

if the leader sequence was deleted from the lysosomal gene, where will the protein reach?
A- cytoplasm
B- ER
C- Golgi
D- lysosome
E- Blood

Answer 13

A- cytoplasm

I think Salman said something about M-6-P. check.

Question 14

Which technique is used to separate protein/DNA fragments based on their size?
a - DNA fingerprinting
b - Gel electrophoresis
c - sequencing

Answer 14

b - Gel electrophoresis

Question 15

What is mostly affected by antibiotic during translation?
A - initiation
B - elongation
C - termination

Answer 15

no answer

but I think it’s B

Question 16

What causes Osteogenesis Imperfecta?
A- gene mutation
B- vitamin c deficiency
C- copper deficiency

Answer 16

A- gene mutation

Question 17

What epigenetic changes occur in DNA?
A- modification of DNA base
B- change in the nucleotide sequence
C- hydrogen bond synthesis
D- phosphodiester bond synthesis

Answer 17

A- modification of DNA base

Question 18

What is the characteristic of the human genome?
A - diploid in all cells
B - only few lack introns
C - most are coding DNA
D - all genes are similar in size

Answer 18

B - only few lack introns

Question 19

What is the significance of annealing in PCR?
A - binding primer
B - unattachment of DNA strand
C - initiation of polymerase

Answer 19

A - binding primer

Question 20

which of the following forces are not involved in the secondary structure of collagen?

a) H-bonds
b) S-S bonds
c) Hydrophobic interactions
d) Van der waals

Answer 20

c) Hydrophobic interactions

Question 21

What of the following feature are shared between the isozymes?

a) they work with the same catalysts
b) they have the same secondary structure
c) they are located in the same tissue
d) they work on the same reaction

Answer 21

d) they work on the same reaction

Question 22

what is true about the telomeric DNA sequence?
A- coding sequence
B- located in the centromeric region
C- hexanucleotide DNA sequence

Answer 22

C- hexanucleotide DNA sequence

Question 23

What is the amplification of DNA after 6 cycles in the PCR?
A - 16
B - 32
C - 64
D - 6

Answer 23

C - 64

Question 24

Which transcription factor has DNA unwinding activity?
A) TFIID 
B) TFIIS 
C) TFIIH 
D) TFIIF

Answer 24

D) TFIIF

TFIIF = Transcription factor II F

Question 25

how does an enzyme accelerate a reaction?
A) stabilize transition state
B) change free change of overall reaction
C) change energy of the product
D) change energy of the reactants

Answer 25

A) stabilize transition state

Question 26

An enzyme that exhibits Michales mentin activity, if a non-competitive inhibitor drug is administered, what will happen? 
A-Km increase
B-Km decrease
C-Vmax increase
D-Vmax decrease

Answer 26

D-Vmax decrease

Question 27

What can be determined from free energy change in a reaction?
A) Direction of metabolites
B) Direction of the pathway

Answer 27

B) Direction of the pathway

Question 28

What causes Alzehmier disease? 
A) proteolysis of amyloid plaque 
B) prions
C) deoxygenated valine Beta hemoglobin
D) beta sheet accumulation

Answer 28

A) proteolysis of amyloid plaque

Question 29

Which one is a characteristic of mRNA polyA tail?
A) Uncoded by DNA
B) Cleaved by H1
C) Removed by SNURPS

Answer 29

A) Uncoded by DNA

Question 30

In which nucleotide sequence of the proximal DNA sequence, where does methylation most commonly occur?
A- AMP 
B- TMP 
C- CMP 
D- GMP

Answer 30

C- CMP

Cytidine monophosphate

Question 31

What is the morphology of sickle cell anemia?
A. aggregation in low oxygen
B. Polymerization
C. Oxidation

Answer 31

A. aggregation in low oxygen

Question 32

Which amino acid is phosphorylated to regulate enzymatic activity?
A) Proline 
B) Glutamine 
C) Lysine 
D) Alanine
E) Serine

Answer 32

E) Serine

Question 33

Which of the following is a characteristic of alternative splicing?
A) mRNA modification
B) DNA modification
C) a lot of introns

Answer 33

A) mRNA modification

Question 34

which of these is used to synthesize glycogen?
A) UTP-glucose
B) UDP -glucose
C) glucose-6-phosphate 
D) glucose-1-phosphate 
E) free glucose

Answer 34

B) UDP -glucose

Question 35

At what base pair of intron N-terminus is cut?
A) 5’ AG 3’ 
B) 5’ GG 3’ 
C) 5’ AA 3’ 
D) 5’ GU 3’

Answer 35

D) 5’ GU 3’