3.1.5.1-DNA and RNA

Question 1

What is DNA?

Answer 1

A polymer made up of nucleotide monomers

Question 2

Describe the structure of DNA

Answer 2

Polymer of nucleotides
Each nucleotide formed from deoxyribose,a phosphate group and a nitrogenous base
Double helix
Phosphodiester bonds between nucleotides
Hydrogen bonds between adenine,thymine and cytosine,guanine

Question 3

How do polynucleotides form from a nucleotide?

Answer 3

A condensation reaction between the sugar and phosphate group of two nucleotides forming a phosphodiester bond

Question 4

Describe how a phosphodiester bonds between nucleotides is formed between two nucleotides within a DNA molecule

Answer 4

Condensation reaction
Between phosphate and deoxyribose
Catalysed by DNA polymerase

Question 5

How is the DNA double helix created?

Answer 5

The DNA polymer occurs in pairs joined together by hydrogen bonds between complementary base pairs

Question 6

DNAs structure related to its function

Answer 6

Complementary base pairing-Allows identical copies to be made by semi-conservative replication
Double stranded-act as templates during semi-conservative replication so identical copies can be made
Weak hydrogen bonds-Double strand seperates more easily for replication
Large molecule-Carries a lot of information
Sugar Phosphate backbone-Protects bases

Question 7

Function of DNA and RNA

Answer 7

DNA holds genetic information
RNA transfers genetic information from DNA to ribosomes

Question 8

Outline the similarities and the differences between the structures of DNA and RNA molecules

Answer 8

DNA=deoxyribose sugar RNA=ribose sugar

DNA=thymine
RNA =,uracil

DNA=double stranded
RNA=single stranded

DNA=long molecule
RNA=short

Both polymers of nucleotide monomers
Both have hydrogen bonds
Both have adenine cytosine and guanine as bases

Question 9

What is a ribosome made of?

Answer 9

RNA and proteins

Question 10

What does mRNA stand for

Answer 10

messenger RNA

Question 11

what does rRNA stand for?

Answer 11

ribosomal RNA

Question 12

what does tRNA stand for?

Answer 12

transfer

Question 13

what is the shape of tRNA?

Answer 13

Cloverleaf

Question 14

Name the protein associated with DNA in a chromosome

Answer 14

histone

Question 15

Describe how mRNA is produced in the nucleus of a cell

Answer 15

DNA helicase
Brakes hydrogen bonds
Only one DNA strand acts as a template
RNA nucleotides attract to exposed bases by base pairing
RNA polymerase join nucleotides together
Pre-mRNA spliced to remove introns