3.1.5 Nucleic Acids

Question 1

Name 2 types of nucleic acid?

Answer 1

DNA
RNA

Question 2

What is the structure of the Bases of DNA/ RNA

Answer 2

Purines: double ring, larger, A, G
Pyramidines: single ringed, smaller, C, U, T

Question 3

Bonds in nucleotides

Answer 3

Phosphodiester bond between the bottom of the sugar and top of phosphate ( links nucleotides together)

Ester bond on top of sugar and bottom of phosphate

Glycosidic bond between sugar and base

Question 4

Function and location of mRNA

Answer 4

Brings genetic information from DNA in nucleus to ribosomes in cytoplasm, directs synthesis of polypeptides
Made in nucleus, moves in cytoplasm

Question 5

Function and location of tRNA

Answer 5

transports amino acids to ribosomes and positions each at the correct place on the polypeptide chain
In cytoplasm

Question 6

Function and location of rRNA

Answer 6

Site of polypeptide synthesis
In ribosome

Question 7

Explain semi/“-conservative DNA replication

Answer 7

DNA helices breaks down hydrogen bonds between bases which unwinds DNA into 2 strands

Each original single strand acts as a template for a new strand. Complimentary base paring means that free floating DNA nucleotides are attached and to the complimentary base pair

DNA polymerase joins the nucleotides via a condensation reaction. Each new DNA molecule contains one original stand and one new strand

Question 8

Which direction can DNA polymerase add nucleotides?

Answer 8

At the 3’ end so it moves from 5 to 3

Question 9

Evidence for semi conservative replication

Answer 9

Conservative model:
Shows 1/4 or original dna after 2 replications

Semi conservative:
Shows 1/2 have original DNA present after 2 replications (which is what results show)

Dispersive:
All have original DNA present after 2 replications