Question detail
Draw the structural formula of a peptide bond formed between two amino acids, glycine and alanine. Explain the process of condensation that occurs during this reaction.
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
Question
Type
exam_style
Style
Topic
Amino acids, proteins and DNA (A-level only)
Question
Draw the structural formula of a peptide bond formed between two amino acids, glycine and alanine. Explain the process of condensation that occurs during this reaction.
Answer
The structural formula of the peptide bond between glycine (NH2CH2COOH) and alanine (NH2CH(CH3)COOH) is: NH2CH2CONHCH(CH3)COOH. In the condensation reaction, the carboxyl group (-COOH) of glycine reacts with the amino group (-NH2) of alanine, releasing a molecule of water (H2O) and forming the peptide bond (-CONH-).
Explanation
This answer is strong because it accurately depicts the structural formula of the peptide bond and describes the condensation process, which is essential for understanding how amino acids link to form proteins. The question tests the student's ability to visualize molecular structures and comprehend biochemical reactions.
Common mistake
Peptide Bond Drawing Error
Students often incorrectly draw the peptide bond by not showing the correct connection between the amine and carboxylic acid groups.
To correctly draw a peptide bond, remember that it forms between the carbon of the carboxylic acid group and the nitrogen of the amine group. The formula for the peptide bond is R1CO-NHR2, where R1 and R2 are the side chains of the amino acids. Ensure to illustrate the loss of a water molecule (H2O) during the condensation reaction.
Related flashcards
Flashcard 1 of 5
Related practice questions
Question 1 of 5
Choose an answer, get feedback, then move sideways through the set.