3.1.5 nucleic acids

Question 1

What does semi-conservative replication mean?

Answer 1

• Each stand acts as a template
• Daughter DNA has one new stand and one original parent stand

Question 2

Explain the process of semi-conservative replication in DNA

Answer 2

• Enzyme DNA helicase breaks hydrogen bonds between complementary base pairs so the strands separate
• Allows complementary DNA nucleotides to align next to exposed bases of both DNA template strands
• Energy from ATP used to activate the nucleotides
• Enzyme DNA polymerase joins adjacent activated nucleotides together by making phosphodiester bonds

Question 3

What do DNA and RNA stand for?

Answer 3

Deoxyribonucleic acid
Ribonucleic acid

Question 4

Which bonds join monomers in DNA and RNA?

Answer 4

Phosphodiester

Question 5

Describe the structure of DNA

Answer 5

• polymer of nucleotides
• each nucleotide formed from deoxyribose, a phosphate group, and organic nitrogen-containg base
• phosphodiester bonds between nucleotides
• double helix held together by hydrogen bonds
• Double stranded helix with a sugar phosphate backbone
• complementary base pairing between g,c and a,t held together by hydrogen bonds
  *Long, large molecule
  *Coiled into helix
  *Sequence of bases
  *Double stranded
  *Many hydrogen bonds)

Question 6

What is the function of DNA being a large, long molecule?

Answer 6

Can store a lot of information

Question 7

Why do DNA molecules have many hydrogen bonds between strands?

Answer 7

• Stands can separate for replication
• Stable and strong

Question 8

What is the function of double stranded helix with a phosphate backbone in DNA?

Answer 8

• Provides strength and stability
• Protects bases

Question 9

What is the function of DNA being could into a helix?

Answer 9

Compact

Question 10

What is the function of DNA and RNA

Answer 10

• Stores genetic information
• Transfers genetic information from DNA ( in nucleus) to ribosomes (in cytoplasm) during transcription and translation

Question 11

What is the function of the sequence of bases in DNA?

Answer 11

Allows information to be stored and codes for sequence of amino acids/polypeptide

Question 12

What is the function of DNA being double stranded?

Answer 12

• Replication can occur semi-conservatively
• Both strands can act as templates
• Complementary base pairings
• A-T and G-C so accurate replication
• Identical copies can be made

Question 13

How stable are DNA and RNA?

Answer 13

DNA very stable, RNA unstable

Question 14

What does the enzyme DNA ligase do?

Answer 14

Joins DNA fragments in the strand that is replicated in short sections

Question 15

How are monomers of DNA and RNA formed?

Answer 15

Condensation reactions

Question 16

Describe the experiment proving DNA replicates semi-conservatively

Answer 16

• All bacteria are grown in 15N (bases contain nitrogen)
• They are transferred to 14N for one generation
• They are transferred to 14N for another generation
• DNA is extracted and separated by density
• Lines will appear in test tube depending on their density

Question 17

What are the different types of RNA ?

Answer 17

Ribosomal
Transfer
Messanger

Question 18

What monomers make up DNA and RNA?

Answer 18

DNA nucleotide
RNA nucleotide

Question 19

What organic nitrogen-containing bases are in DNA and RNA?

Answer 19

DNA: Adenine, thymine, guanine, cytosine
RNA: adenine, guanine, cytosine, uracil