Biochem: Molecular Bio

Question 1

T/F: Amino acids are produced by the hydrolysis of nucleic acids.

Answer 1

False

Question 2

What are the three major groups that make up DNA?

Answer 2

Sugar (-ose), phosphate, and amine base

Question 3

Which base pair will have three hydrogen bonds?

Answer 3

G and C will always have THREE

A-T/U has two hydrogen bonds

Question 4

T/F: A bond between guanine and cytosine will have a higher melt temp than adenine and thymine.

Answer 4

True

More bonds = stronger bond = higher melt temp

Question 5

Which nucleotides are purines?

Answer 5

Pure Silver (Ag)

Adenine and guanine are purines

Question 6

Which nucleotides are pyrimidines?

Answer 6

CUT the Py

Cytosine, Thymine, and uracil are pyrimidines

Question 7

What type of bond links the monomeric units of nucleic acids?

Answer 7

Phosphodiester bonds at third and fifth carbons

Question 8

T/F: DNA with a higher G-C content will have a higher melt temp.

Answer 8

True

Question 9

Which base pair is found in DNA but not RNA?

Answer 9

A-T

Replaced with A-U

Question 10

Histones add strength and support to DNA. What are they made of?

Answer 10

Basic amino acids such as lysine and arginine

Question 11

Which RNA type is the most prevalent?

Answer 11

rRNA

Question 12

T/F: mRNA contains the anticodon for ribosomes to read.

Answer 12

False

mRNA carries codon out of nucleus to ribosomes

Question 13

T/F: Purines contain two ring structures.

Answer 13

True

Question 14

What type of bonds hold the histone complex together?

Answer 14

Ionic bonds

Question 15

What are the four major enzymes in DNA replication and what are their functions?

Answer 15

1. Helicase - unwinds
2. Primase - starts
3. DNA polymerase - forms new DNA in 5’->3’
4. Ligase - joins Okazaki fragments to the lagging strand

Question 16

New DNA is always formed in which direction?

Answer 16

5’->3’

Question 17

What is the difference on the leading strand vs the lagging strand?

Answer 17

When DNA is split - the end with 3’ is leading strand and the end with 5’ is lagging strand

DNA polymerase can run from 3’->5’ (leading strand) continuously

Since lagging strand runs from 5’->3’, DNA polymerase makes Ozaki fragments

Question 18

T/F: Introns are removed from RNA in splicing.

Answer 18

True

Question 19

Which enzyme catalyzes formation of uric acid from purines?

Answer 19

Xanthine oxidase

Question 20

T/F: mRNA activates and selects the specific amino acids for protein synthesis.

Answer 20

False

tRNA does this with anticodon

Question 21

HIV and Hep B utilize which enzyme to copy RNA into cDNA?

Answer 21

Reverse transcriptase

Question 22

How does UV light damage DNA?

Answer 22

Dimerization adding bonds between thymine groups

Question 23

T/F: Enzymes always read in 3’->5’ and build in 5’->3’.

Answer 23

True

Question 24

What are the three codons that are nonsense and do not code for an amino acid (termination)?

Answer 24

UAA, UAG, UGA

Question 25

What is the start codon?

Answer 25

AUG - Methionine

Question 26

Replacement of guanine with an adenosine would be a ________ mutation.

Answer 26

transition

transverse is when pyrimidine is replaced with purine or vice versa

Question 27

What is a missense mutation?

Answer 27

Causes new amino acid

Question 28

What is the action of exonuclease?

Answer 28

Removes nucleotides to repair DNA

Question 29

T/F: DNA replication, translation, and protein synthesis all occur in the M phase of the cell cycle.

Answer 29

False

Question 30

Which phase involves DNA replication?

Answer 30

S phase

Question 31

Which various blotting techniques identify which structures?

Answer 31

Sunny Day, No Rain, Warm Picnic

Southern: DNA
Northern: RNA
Western: Protein

Question 32

T/F: Western blots use cDNA as a probe.

Answer 32

False

Antibodies

All others use cDNA

Question 33

What will molecules do once they reach the their isoelectric pH in gel electrophoresis?

Answer 33

Stop moving

Question 34

Which way will a molecule move a the pH is below the isoelectric point?

Answer 34

Toward the anode (negative pole)