Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

3. Amino Acids

Amino Acid Groups

Biochemistry

3. Amino Acids

Amino Acid Groups

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Multiple Choice

Which type of heterocycle is found on two amino acid residues, thereby blocking access to the tryptophan residue at position 15 (w15)?

Pyrrolidine

Pyrrole

Indole

Imidazole

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Verified step by step guidance

Understand the question: The problem is asking about the type of heterocycle found on two amino acid residues that blocks access to the tryptophan residue at position 15 (W15). The options provided are Pyrrolidine, Pyrrole, Indole, and Imidazole.

Recall the structure of tryptophan: Tryptophan contains an indole group as part of its side chain. This is important because the question involves blocking access to this residue.

Review the structures of the heterocycles listed: Pyrrolidine is a five-membered ring containing nitrogen, Pyrrole is a five-membered aromatic ring with one nitrogen atom, Indole is a bicyclic structure with a benzene ring fused to a pyrrole ring, and Imidazole is a five-membered aromatic ring with two nitrogen atoms.

Consider the interaction: Blocking access to tryptophan (W15) likely involves steric hindrance or specific binding interactions. The heterocycles involved must be compatible with the amino acid residues that interact with tryptophan.

Determine the answer: Based on the structural compatibility and the role of heterocycles in amino acid residues, identify which heterocycles are commonly found in amino acids and could block access to tryptophan. For example, pyrrolidine is found in proline, and imidazole is found in histidine.