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Two common α amino acids (2-amino acids) are cysteine and serine - VCE - SSCE Chemistry - Question 4 - 2005 - Paper 1
Question 4
Two common α amino acids (2-amino acids) are cysteine and serine. Their structural formulas are given below. Cysteine: H O | || H2N--C--C—O... show full transcript
Worked Solution & Example Answer:Two common α amino acids (2-amino acids) are cysteine and serine - VCE - SSCE Chemistry - Question 4 - 2005 - Paper 1
Step 1
What chemical feature must an amino acid have in order to be classified as an α amino acid?
Answer
An amino acid must have both an amino group (-NH2) and a carboxyl group (-COOH) attached to the same carbon atom (the alpha carbon). This structure is essential for its classification as an α amino acid.
Step 2
Cysteine and serine can combine together to form two different dipeptides. Draw the structural formulas of these two dipeptides.
Answer
The two dipeptides that can form from cysteine and serine are:
-
Cysteine-Serine (Cys-Ser):
H O | ||
H2N—C—C—OH
|
SH
|
C—C—OH
|
H
2. Serine-Cysteine (Ser-Cys):
H O
| ||
H2N—C—C—OH
|
OH
|
C—C—SH
|
H
Step 3
Step 4
Why is the tertiary structure of an enzyme essential to its function?
Answer
The tertiary structure of an enzyme is essential to its function because it determines the enzyme's active site shape, which is crucial for substrate binding and catalysis. Any changes or denaturation in this structure can result in loss of activity, as the enzyme may no longer fit the substrate properly.