Chp 10 Structure and function of DNA

Question 1

List the components of a nucleotide:

Answer 1

Nitrogenous base (Pyrimidine of purine) • 
Pentose sugar
Phosphate group(s)

Question 2

What is monomer of DNA?

Answer 2

nucleotides

Question 3

What is the structure of DNA according to Watson and Crick?

Answer 3

Double helix

Question 4

List three differences between DNA and RNA

Answer 4

instead of thymine, RNA has a similar base called uracil (U), and
• RNA contains a slightly different sugar than DNA (ribose instead of deoxyribose, accounting for the names RNA vs. DNA).

Question 5

the sequence for the newly formed strand of DNA after replication.

Answer 5

A - T
T - A
C- G
G - C
T - A
A - T
C - G

Question 6

What is the function of DNA polymerase?

Answer 6

Enzymes that make the covalent bonds between the nucleotides of a new DNA strand and can repair DNA.

Question 7

Define: Transcription

Answer 7

Transcription is the transfer of genetic information from DNA to RNA which happens in the nucleus
• As with DNA replication, two DNA strands must first separate at the place where the process will start.
• In transcription, however, only one of the DNA strands serves as a template for the newly forming RNA molecule; the other strand is unused.

Question 8

List the 3 stages of transcription.

Answer 8

Initiation, Elogation, Termination

Question 9

A. Initiation

Answer 9

attachment of RNA polymerase to the promoter (beginning of the gene

Question 10

B. Elongation

Answer 10

Synthesis of RNA, RNA strand separates from its DNA template

Question 11

Termination

Answer 11

Polymerase reaches the terminator, signaling the end of the gene

Question 12

11. What is the function of a promoter and where is it present?

Answer 12

Beginning of the gene, starts the RNA synthesis

Question 13

What is the terminator and where is it present?

Answer 13

A special sequence of bases in the DNA template, signals the end of the gene.

Question 14

12. What is the terminator and where is it present?

Answer 14

A special sequence of bases in the DNA template, signals the end of the gene.

Question 15

What is the function of transcription factors?

Answer 15

Transcription is the transfer of genetic information from DNA to RNA which happens in the nucleus
• As with DNA replication, two DNA strands must first separate at the place where the process will start.
• In transcription, however, only one of the DNA strands serves as a template for the newly forming RNA molecule; the other strand is unused.
• Notice that the RNA nucleotides follow the usual base- pairing rules, except that U, rather than T, pairs with A.

Question 16

What is the function of RNA polymerase?

Answer 16

Synthesis of mRNA

Question 17

What is the function of mRNA?

Answer 17

Carried the genetic information copied from DNA in the form of a 3-base code, each specifies a particular amino acid.

Question 18

Define Codon:

Answer 18

A genetic code that is a sequence of 3 bases on RNA molecule.

Question 19

Define Anticodon:

Answer 19

Sequences of nucleotides that are complementary to codons. Found in tRNAs.

Question 20

Define Mutation

Answer 20

any change in nucleotide sequence of a cell’s DNA . Can involve large regions of a chromosome or a single nucleotide pair. Like Sickle-cell disease

Question 21

Explain why HIV virus is called a retrovirus?

Answer 21

because they reverse the usual DNA  RNA flow of genetic information.

Question 22

Which of the following correctly ranks nucleic acid structures in order of size, from largest to smallest?

Answer 22

chromosome, gene, codon, nucleotide

Question 23

A new DNA double helix consist of

Answer 23

one old and one new strand

Question 24

DNA replication requires…

Answer 24

the cooperation of over a dozen enzymes and other proteins.

Question 25

How many nucleotides make up a codon?

Answer 25

three

Question 26

The RNA that is translated into a polypeptide is ______ RNA.

Answer 26

messenger

Question 27

During translation, what is the correct order of events that occur as an amino acid is added?

Answer 27

codon recognition, peptide bond formation, translocation