Mutations

Question 1

What are the steps in determining gene function?

Answer 1

1. Find a start codon and a stop codon.
2. Find a promoter
3. Between the start and stop codon you will find the coding region called a gene.
4. Compare 6 frames, the longest one is the most likely protein
5. Use database to find similar proteins (BLAST)
6. Translate mRNA into proteins

Question 2

What are domains/motifs?

Answer 2

These are units within the proetin that have their own function.

Question 3

What is a mutation?

Answer 3

A change in the nucleotide sequence of the DNA.

Question 4

What is a Point Mutation?

Answer 4

Affects a single nucleotide position. It can be Silent, missense and nonsense.

Question 5

What is a Missense point mutation?

Answer 5

change of one nucleotide in DNA which results in a change in the mRNA codon to one that encodes a different amino acid and causes a change in the protein produced.

Question 6

What is a somatic mutation?

Answer 6

Occurs in cells not dedicated to sexual reproduction.

Question 7

What are germline mutations?

Answer 7

occur in the DNA of an organism’s germline cells, which are the cells responsible for giving rise to gametes (sperm and egg cells) in sexually reproducing organisms.

Question 8

What is a substitute mutation?

Answer 8

Exchanges one base for another.

Question 9

What type of mutation is sickle cell?

Answer 9

Missense

Question 10

What is a nonsense point mutation?

Answer 10

Changes an amino acid codon to stop codon thereby producing an incomplete protein.

Question 11

What is a silent mutation?

Answer 11

This occurs when a substitution results in an mRNA codon changing to another codon that encodes the same amino acid.

Question 12

What is a frameshift mutation?

Answer 12

Insertion and deletion involving one or multiple of two base pairs resulting in a change of the reading frame.

Question 13

What is called when one purine [A or G] or pyrimidine [C or T] is replaced by the other?

Answer 13

Transition

Question 14

What is it called when a purine is replaced by a pyrimidine or vice-versa?

Answer 14

Transversion

Question 15

Which R groups are found clustered in the core of the protein?

Answer 15

Non polar (Hydrophic) groups

Question 16

Which R groups are often found on the surface of the protein?

Answer 16

Polar Groups

Question 17

Name two amino acids with negative charge?

Answer 17

Aspartic acid and Glutamic acid

Question 18

What three main categories are R groups broken into?

Answer 18

Non polar
Polar
Charged

Question 19

Describe the primary strcuture of proteins

Answer 19

A sequence of Amino acids held together by peptide bonds.

Question 20

Describe the Secondary protein structure

Answer 20

• Formed by hydrogen bonding between peptide bonds.
• Common secondary structures include α-helices and β-sheets.
• R groups do not directly participate in secondary structure formation.

Question 21

Describe the Tertiary Structure

Answer 21

• Determined by interactions between R groups, including hydrophobic interactions, hydrogen bonds, ionic bonds, and disulfide bonds (cysteine residues).

Question 22

Describe the Quaternary Structure

Answer 22

• Present in proteins composed of multiple polypeptide chains (subunits).
• Defines the spatial arrangement and interactions between subunits.
• Examples include hemoglobin and collagen.