Nucleic Acids

Question 1

2’ C position

Answer 1

RNA has an OH, but DNA has only -H

Question 2

U =

T =

Answer 2

RNA

DNA

Question 3

A gene is made of this macromolecule:

Answer 3

DNA

Question 4

Chromatin is made of these macromolecules:

Answer 4

DNA and proteins

Question 5

The two strands of DNA that make up a double helix are held together by:

Answer 5

hydrogen bonds between purine and pyrimidine bases

Question 6

A single strand of DNA is a polymer whose subunits are connected by:

Answer 6

Phosphodiester bonds

Question 7

Uracil pairs with:

Answer 7

Adenine

Question 8

The following are true regarding the structure of DNA and RNA:

Answer 8

• The bases found in RNA are not all the same as in DNA
• the sugars differ slightly between RNA and DNA
• DNA and RNA are both synthesized from 5’ to 3’

Question 9

What does it mean when we say that DNA strands in a double helix are antiparallel?

Answer 9

Each strand has 5’ to 3’ polarity, but in opposite directions

Question 10

Which class of macromolecule is capable of catalyzing chemical reactions?

Answer 10

Both proteins and RNAs

Question 11

What does the primase enzyme do?

Answer 11

Synthesizes a short section of RNA complementary to a single-stranded DNA template

Question 12

The enzyme helicase:

Answer 12

Unwinds DNA strands from one another during DNA replication

Question 13

Coding strand to:

Answer 13

RNA sequence (T to U)

Question 14

Transcription

Answer 14

The copying of DNA to RNA

Question 15

In a eukaryotic cell, a primary RNA transcript may contain may contain all of the following the info to specify the amino acid sequence of a polypeptide

Answer 15

• A 5’ untranslated region
• A start codon
• A splice site

Question 16

A transcription termination site is recognized by:

Answer 16

RNA polymerase

Question 17

When a gene is transcribed once, it generates:

Answer 17

only a single mRNA molecule but many copies of a protein can be translated from that single mRNA

Question 18

What tells a ribosome that it should not add any more amino acids to a growing protein?

Answer 18

A stop codon

Question 19

The enzyme glycine-tRNA synthetase recognizes

Answer 19

the amino acid glycine

Question 20

The change that takes place in the lac repressor when it binds to lactose is an example of:

Answer 20

allosteric regulation

Question 21

It it hypothesized that this macromolecule was the first to have the ability to replicate itself:

Answer 21

RNA

Question 22

If a DNA sequence error is made during DNA replication, the sequence is likely to be repaired by:

Answer 22

proofreading by DNA polymerase during DNA replication

Question 23

The loss or mutation of a single amino acid can lead to which of the following disorders:

Answer 23

• sickle cell anemia
• cystic fibrosis
• hereditary hemochromatosis

Question 24

Where is the primary transcript found in the cell?

Answer 24

Nucleus

Question 25

Mature mRNA components:

Answer 25

5' - 5' cap - exons - 3' poly(A)tail - 3'

Question 26

Where is the mature transcript found in the cell?

Answer 26

It becomes mature in the nucleus and is then exported to the cytoplasm