Draw the possible dipeptide, where −NH2 group of serine is free, formed by the condensation reaction between serine and lysine.
The dipeptide formed by the condensation reaction between serine and lysine is Serine-Lysine or Ser-Lys. The chemical structure is:
HOOC-CH(NH2)-CH2-OH + H2N-(CH2)4-CH(NH2)-COOH → HOOC-CH(NH-CH2-CH2-NH-C-(CH2)4-CH(NH2)-COOH + H2O
In simpler terms, the carboxyl group of serine (HOOC) combines with the amine group of lysine (H2N) with the loss of a water molecule, forming a peptide bond (-CO-NH-). The resulting dipeptide has the amino acid sequence Ser-Lys, where the −NH2 group of serine remains free.
To draw the dipeptide formed by the condensation reaction between serine and lysine, you will need to combine the amino acids and remove a water molecule. Here are the steps to draw the dipeptide:
Step 1: Draw the structure of serine:
H
|
HO-C-COOH
|
CH2OH
Step 2: Draw the structure of lysine:
H
|
H2N-C-(CH2)4-CH2-COOH
|
NH2
Step 3: Combine the two amino acids by condensing the −COOH group of serine with the −NH2 group of lysine. Remove a water molecule (H2O) during the condensation reaction.
H
|
HO-C-C-NH-(CH2)4-CH2-COOH
|
CH2OH
This is the structure of the dipeptide formed by the condensation reaction between serine and lysine, where the −NH2 group of serine is free.