Mutations

Question 1

Mutations can be caused by

Answer 1

Mutagens (substances such as UV radiation, which damage DNA) or errors during DNA replication. Final base sequence is changed

Question 2

Point mutation 1

Answer 2

Base substitution - one base has been affected, 3rd amino acid changed from ARG TO TRP

Question 3

Point mutation 2

Answer 3

Is also substitution, BUT is SILENT MUTATION: change in base sequence codes for same amino acid ARG. DUE TO DEGENERACY OF THE CODE LEADING TO REDUNDANCY

Question 4

There are __ amino acids and __ triplets/codon

Answer 4

20 amino acid and 64 triplets

Question 5

This means that an amino acid..

Answer 5

Will have more than one triplet that codes for it

Question 6

BOTH point 1 or point 2 mutation will have..

Answer 6

NO frameshift (where bases move L TO R in base deletion OR insertion that is not a multiple of three); number of AMINO acids still the same,
NO EFFECT on start and stop codons of both mutations

Question 7

Point 1 mutation will have..

Answer 7

An affect on the final protein enzyme phenylalanine. Change in amino acid = will impact protein folding, shape AND FUNCTION (will not be a bale to catalyse reaction it has intended)

Question 8

However, for point 2 mutation (silent mutation)

Answer 8

The amino acid chain folds correctly as intended, same LENGTH OF AMINO ACID,and thus ENZYME FUNCTIONS exactly as if the mutation did not happen

Question 9

Substitution mutation

Answer 9

Single nucleotide changed = result in a codon that codes for DIFFERENT amino acid

Question 10

Insertion

Answer 10

Base inserted in base sequence

Question 11

Deletion

Answer 11

A base removed from DNA sequence

Question 12

Not all SUBSTITUTION result in new amino acids due to…

Answer 12

Redundancy of the code

Question 13

Substituted means that

Answer 13

The strand has correct number of bases, stop and start codon not affected and PROTEIN can be MADE

Question 14

Due to degeneracy (same) of the code..

Answer 14

A silent mutation may code for same amino acid and due to same amino acid the FINAL PROTEIN is correct shape and function

Question 15

However, a substation mutation can also..

Answer 15

Cause final protein/polypeptide to fold incorrectly so does not catalyse a reaction intended/function affected.

Question 16

Both insertion and deletion causes…

Answer 16

Frameshift mutation bc CHANGE in number of bases /length of gene (increasing or decreasing) the dna sequence

Question 17

Adding and removing single bases..

Answer 17

Every codon from the POINT OF MUTATION is affected (reading frameshift)

Question 18

Reading frameshift affects..

Answer 18

The stop and start codons which affects length of amino acid chain and its structure of folding in final protein

Question 19

Insertion and deletion affect final protein the most, more than…

Answer 19

Substitution (as it affects one triplet) and THEREFORE one amino acid in polypeptide chain = Change in shape of protein

Question 20

Insertion and deletion results in..

Answer 20

Amino acids AFTER mutation to be incorrect, folding incorrectly, drastic change in shape = non-functional, STOP AND START CODIN TOO early and terminate too early, causing shorter chain, too late