Substitution of an amino acid may or may not result in a significant change in p

Question

Substitution of an amino acid may or may not result in a significant change in protein structure and function. Explain?

Which two of the following would not be considered a covalent modification of protein?

A)attachment of a carbohydrate B)attachment of a phospholipid C)removal of a signal sequence D)reversable change in shape due to binding of a ligand E)reduction in enzymatic activity at suboptimal temperature or PH

Which is a variable portion of a nucleic acid? A)a base such as adenine B)a phosphate C)5-carbon sugar D)amino acid E)disulfide bond

Which two of the following are examples of covalent bonds? A)a bond of hydrogen to carbon B)binding of two hydrogen atoms to an oxygen atom to form a molecule of water C)binding of sodium and chlorine in table salt D)attraction between water molecules

Explanation / Answer

Answer:

1. In substitution mutation, one base is replaced by one of the other three bases.

A substitution may adversely effect the structure and function of a protein in case of:

i. Missense mutation: changes an amino acid to another amino acid. This may or may not affect protein function, depending on whether the change is “conservative” or “nonconservative,” and what the amino acid actually does.

ii. Nonsense mutation: changes an amino acid to a STOP codon, resulting in premature termination of translation.

A substitution mutation may not effect the structure and function of a protein in case of:

Silent mutation: It does not change an amino acid, but in somecases can still have a phenotypic effect, e.g. by speeding up or slowing down protein synthesis, or by affecting splicing.

2. (E) reduction in enzymatic activity at suboptimal temperature or pH

3. (A) A base such as adenine.

There are 4 bases in DNA: Adenine, Guanine, Thymine and Cytosine.

4. (A) A bond of hydrogen to carbon, and

(B) Binding of two hydrogen atoms to an oxygen atom to form a molecule of water

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.