Proteins, Mutations & Genetic Disorders

Question 1

What is a mutation

Answer 1

-Spontaneous, random and permanent changes to the structure of DNA.
-Results in an altered protein or no protein being synthesized.

Question 2

What is a gene mutation

Answer 2

Affects the DNA nucleotide sequence of a single gene.

Question 3

How many types, and what are the names of the main types of genetic mutation.

Answer 3

3 main types of genetic mutation
-Insertion
-Deletion
-Substitution

Question 4

What is an insertion genetic mutation

Answer 4

A DNA nucleotide is added into the DNA sequence of a gene

Question 5

How does a insertion/deletion genetic mutation influence the structure of a protein

Answer 5

Alters all codon sequences and amino acids after the point of mutation.
Has a major effect on the structure of the protein produced - The protein produced will most likely be non-functional

Question 6

What is a deletion genetic mutation

Answer 6

A DNA nucleotide is removed from the DNA sequence of a gene.

Question 7

What is a frameshift genetic mutation

Answer 7

Insertion/Deletion mutations are known as frameshift mutations as they shift the bases, affecting the triplet code sequences and ultimately the overall structure of the protein.

Question 8

What is a substitution genetic mutation

Answer 8

A DNA nucleotide is exchanged for another DNA nucleotide with a different base.

Question 9

What type of mutation is a substitution genetic mutation

Answer 9

A point mutation, Alters one codon sequence and one amino acid, at the point of mutatio0n.
-Depending on the nucleotide affected the consequences can greatly vary.

Question 10

What are the three types of substitution genetic mutation

Answer 10

1) Missense substitution mutation
2) Nonsense substitution mutation
3) Splice-site substitution mutation

Question 11

What is a missense substitution mutation

Answer 11

Altered codon codes for a different amino acid.

Question 12

What impact does a missense substitution mutation have on the protein produced

Answer 12

Protein produced may be unaffected or non-functional

Question 13

What is a nonsense substitution mutation

Answer 13

Altered codon codes for a premature stop codon

Question 14

What impact does a nonsense substitution mutation have on the structure of the protein produced

Answer 14

The protein produced is shorter in length

Question 15

What is a splice-site substitution mutation

Answer 15

Altered codon retains introns/excludes exons from mRNA transcript

Question 16

What impact does a splice-site substitution mutation have

Answer 16

Produces a completely different protein.

Question 17

What effect does a mutation have on the protein formed

Answer 17

-Changes in an individual genotype affect the structure and function of the proteins they are able to produce
-Leads to phenotypic alteration that may have detrimental effects on the health of the individual affected.

Question 18

What is phenylketonuria

Answer 18

A genetic condition caused by a missense substitution mutation, unable to break down phenylalanine, so it build up in the blood and high levels can damage the brain.
Enzyme Activity non functional
Pheneylalanine ———————————————-> Tyrosine

Question 19

What is thalassemia

Answer 19

Disease caused by splice site substitution mutation causes defect in haemoglobin synthesis.
Normal haemoglobin has 4 oxygen carrying units, abnormal has only 2.

Question 20

What is a chromosomal mutation

Answer 20

a change in the number of chromosomes or their structure which often occurs as a result of error in meiosis.

Question 21

What are the four types of chromosomal mutation

Answer 21

1) Deletion
2) Duplication
3) Translocation
4) Inversion

Question 22

What is a deletion chromosomal mutation

Answer 22

A section of a chromosome is removed

Question 23

What is a duplication chromosomal mutation

Answer 23

A section of a chromosome is added from its homologous partner.

Question 24

What is a translocation chromosomal mutation

Answer 24

A section of a chromosome is dislocated and added to another chromosome that is not its homologous partner.

Question 25

What is a inversion chromosomal mutation

Answer 25

A section of a chromosome is reversed

Question 26

What are the effects of deletion and duplication chromosomal mutations to the functioning of the cell

Answer 26

-Substantial changes in the structure of chromosomes often make them lethal to cell function as many genes are lost or repeated

Question 27

What are the effected of translocation and inversion chromosomal mutations to the functioning of the cell

Answer 27

Inversion and translocation chromosomal mutations have less impact on cell function since all genetic material remains present in the cell, all genetic information is present in the cell but some will be in the wrong place.

Question 28

What is a karyotype

Answer 28

A diagram which shows chromosomes lined up in their homologous pairs.

Question 29

What is a deletion genetic and deletion chromosomal mutation

Answer 29

**Deletion Genetic Mutation** -A DNA nucleotide is removed from the DNA sequence of a gene. -Influences structure of a protein as it Alters all codon sequences and amino acids after the point of mutation. Has a major effect on the structure of the protein produced - The protein produced will most likely be non-functional **Deletion Chromosomal Mutation** -A section of a chromosome is removed -Affected functioning of the cell as makes Substantial changes in the structure of chromosomes often make them lethal to cell function as many genes are lost or repeated.