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Flashcards in 2015 biochem midterm Deck (50)
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1

What percentage of the genome do repetitive elements contribute to?
a) 45%
b) 3.5%
c) 2%
d) 10%

a) 45%

2

Where can we find Satellite DNA?
a) Heterochromatin
b) LINEs
c) SINEs
d) Euchromatin

a) Heterochromatin

3

What leads to frame shift mutation?
a) Missense
b) Deletion
c) Inversion
d) Replication

b) Deletion

4

Deamination of cytosine is fixed by what repair mechanism?
a) Base Excision Repair
b) Nucleotide Excision Repair
c) Mismatch repair mechanism
d) DNA replication

a) Base Excision Repair

5

What is a characteristic of mRNA?
a) Make 15% of total RNA in cell
b) Make 80% of total RNA
c) Include modified bases
d) Monocistronic

d) Monocistronic

6

What is the purpose of using dd-NTP?
a) Base-Selective inhibition of DNA synthesis
b) Increases the rate the process
c) Minimize lost fragment
d) Repairs destroyed fragments

a) Base-Selective inhibition of DNA synthesis

7

What is the annealing temperature in the following primer:
5’ - AAA TTT AAG TGG CCG CCC - 3’
a) 54 C
b) 56 C
c) 73 C
d) 24 C

a) 54 C

8

If we standardize the environment during the process of electrophoresis, what will the separation be based on?
a) size
b) charge
c) electrode quality
d) transport medium

a) size

9

Which part of tRNA attaches to amino acids?
a) Tau arm
b) anti-codon arm
c) acceptor arm
d) Modified bases arm

c) acceptor arm

10

Which of the following is characteristic of mRNA capping?
a) Linked in a 5’ to 5’ fashion
b) Poly A-tail
c) Helps in the splicing process
d) Hinders the transport of mRNA

a) Linked in a 5’ to 5’ fashion

11

What is the splice site at the 3’ site of an intron?
a) 5’ GU 3’
b) 5’ CG 3’
c) 5’ AG 3’
d) 5’ AC 3’

c) 5’ AG 3’

12

What is the primary site in the regulation of gene expression?
a) transcription
b) post-transcription
c) post-translation
d) DNA modification

a) transcription

13

What is the function of specific transcription factors?
a) Involved in transcription elongation
b) Involved in transcription initiation
c) Involved in transcription termination
d) Cis-acting molecules

b) Involved in transcription initiation

14

A pregnant agouti mouse has yellow coat, fat, and prone to diseases. However, when we introduce vitamin B diet supplements, its children are healthy. How did the diet make this change?
a) hypermethylation of agouti gene promoter
b) hypomethylation of agouti gene promoter
c) acetylation of agouti gene promoter
d) deacetylation of agouti gene promoter

a) hypermethylation of agouti gene promoter

15

In honey bee larvae, royal jelly is used to get worker bees and queen bee through DNMT gene hypermethylation. How are the target genes affected?
a) They will be hypermethylated
b) They will be hypomethylated
c) They will be acetylated
d) They will be deacetylated

b) They will be hypomethylated

16

When an antibiotic binds on 30s subunit on the A site, what will happen during translation?
a) inhibition of elongation
b) inhibition of initiation
c) inhibition of termination
d) cancer

c) inhibition of termination

(I think it's A)

17

If the target sequence of a mitochondrial protein is cleaved, where will it go?
a. mitochondria
b. ER
c. nucleus
d. cytosol

a. mitochondria

18

What is the function of chaperones?
a) bind to exposed hydrophobic aa
b) bind to exposed hydrophilic aa

a) bind to exposed hydrophobic aa

19

Abrupt disruption of secondary protein structure forms which of the following?
a) A – helices
b) B – sheet
c) B – turn
d) Proline

c) B – turn

20

Tertiary structure of protein is stabilized mostly by which of the following?
a) C terminus
b) N terminus
c) peptide bond
d) side chains interaction

d) side chains interaction

21

What is the function of a catalyst?
a) lowering energy of products
b) b- lowering energy of substrates
c) lowering energy of transition state
d) Lowering the free energy

c) lowering energy of transition state

22

If we put 0.1 mM of inhibitor drug on a sample where the Km was 0.5 and vmax was 20, and this inhibitor is non-competitive. What is correct regarding km and vmax after this whole process?
a) vmax = 20, km = 5
b) vmax = 10, km = 0.5
c) vmax = 20 , km = 5
d) vmax = 10 and km = 2.5

b) vmax = 10, km = 0.5

23

Cooperativity gives the sigmoid shape that differs from michaelis-menten equation. What is the characteristic of enzymes that uses cooperativity?
a) narrow change in substrate concentration leads to a big change in reaction rate
b) high affinity at low concentration

a) narrow change in substrate concentration leads to a big change in reaction rate

24

Glycogen synthase uses which of the following substrates to make glycogen chain?
a) glucose-1-p
b) glucose-6-p
c) UDP-glucose
d) UTP-glucose

c) UDP-glucose

25

What determines the direction of a certain reaction pathway?
a) Summation of delta G in each step of the pathway
b) The delta G of the first step
c) The smallest delta G
d) The largest delta G

a) Summation of delta G in each step of the pathway

26

Which of the following metabolites is mostly used in cells for the transfer of energy?
a) ADP
b) ATP
c) NAD+
d) NADP

b) ATP

27

Phenylketonuria is which type of inherited metabolic disorders?
a) disorders of amino acid
b) disorders of carbohydrates
c) disorders of lipids
d) disorders of hormones

a) disorders of amino acid

28

Phenylketonuria is mostly caused due to which type of mutation?
a) inversion
b) deletion
c) insertion
d) missense

d) missense

29

Creutzfeldt-Jakob mad cow disease is due to a change in which of the following protein secondary structures?
a) B sheets
b) A helices
c) B turns
d) No repetitive secondary structure

a) B sheets

30

What ion’s movement is faulty in Cystic Fibrosis?
a) Ca
b) Cl
c) H
d) Li

b) Cl