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18. Using a codon table, the base pair sequence ACA codes which amino acid?

A. Isoleucine
B. Proline
C. Threonine
D. Valine

User Robaatz
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Answer:

C. Threonine

Definitions

⇒ Codon is a triplet of adjacent nucleotides in the messenger RNA chain that codes for a specific amino acid in the synthesis of a protein molecule.

⇒ Adenine is a purine base, C5H5N5, one of the fundamental components of nucleic acids, as DNA, in which it forms a base pair with thymine, and RNA, in which it pairs with uracil. Symbol: A.

⇒ Cytosine is a pyrimidine base, C5H5N3O, that is one of the fundamental components of DNA and RNA, in which it forms a base pair with guanine. Symbol: C.

⇒ Amino acids are any class of organic compounds that contains at least one amino group, -NH2, and one carboxyl group, -COOH: the alpha-amino acids, RCH (NH2) COOH, are the building blocks from which proteins are constructed.

⇒ Isoleucine is a fundamental branched chain aliphatic amino acid found in various proteins.

⇒ Proline is a alcohol-soluble amino acid, C4H9NhCOOH, occurring in high concentration in collagen.

⇒ Threonine is an essential amino acid, CH3CHOHCH(NH2)COOH, obtained by the hydrolysis of proteins.

⇒ Valine is an essential amino acid, (CH3)2CHCH(NH2)COOH, white, crystalline, and water-soluble, present in most plant and animal proteins, required for growth.

To determine which amino acid is coded by the base pair sequence ACA, we need to use a codon table.

Here is a standard codon table:

First Base Second Base Third Base Amino Acid

U U U Phenylalanine (Phe)

U U C Phenylalanine (Phe)

U U A Leucine (Leu)

U U G Leucine (Leu)

U C U Serine (Ser)

U C C Serine (Ser)

U C A Serine (Ser)

U C G Serine (Ser)

U A U Tyrosine (Tyr)

U A C Tyrosine (Tyr)

U A A Stop

U A G Stop

U G U Cysteine (Cys)

U G C Cysteine (Cys)

U G A Stop

U G G Tryptophan (Trp)

C U U Leucine (Leu)

C U C Leucine (Leu)

C U A Leucine (Leu)

C U G Leucine (Leu)

C C U Proline (Pro)

C C C Proline (Pro)

C C A Proline (Pro)

C C G Proline (Pro)

C A U Histidine (His)

C A C Histidine (His)

C A A Glutamine (Gln)

C A G Glutamine (Gln)

C G U Arginine (Arg)

C G C Arginine (Arg)

C G A Arginine (Arg)

C G G Arginine (Arg)

A U U Isoleucine (Ile)

A U C Isoleucine (Ile)

A U A Isoleucine (Ile)

A U G Methionine (Met) or Start

A C U Threonine (Thr)

A C C Threonine (Thr)

A C A Threonine (Thr)

A C G Threonine (Thr)

A A U Asparagine (Asn)

A A C Asparagine (Asn)

A A A Lysine (Lys)

A A G Lysine (Lys)

A G U Serine (Ser)

A G C Serine (Ser)

A G A Arginine (Arg)

A G G Arginine (Arg)

G U U Valine (Val)

G U C Valine (Val)

G U A Valine (Val)

G U G Valine (Val)

G C U Alanine (Ala)

G C C Alanine (Ala)

G C A Alanine (Ala)

G C G Alanine (Ala)

*It goes on.

To answer your question, the base pair sequence ACA codes for the amino acid threonine

User Sashaeve
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