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Ch. 24 - Amino Acids, Peptides, and Proteins
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728당신이 사용하는 게 아니라요?교과서 변경
24장, 문제 4b

Draw the structure of the predominant form of
(b) proline at pH 2.

검증된 단계별 안내
1
Step 1: Understand the structure of proline. Proline is an amino acid with a unique cyclic structure where the amino group is part of a five-membered ring. Its chemical formula is C5H9NO2, and it contains both an amino group (-NH2) and a carboxylic acid group (-COOH).
Step 2: Recall the behavior of amino acids at low pH. At pH 2, the environment is highly acidic, meaning there is an abundance of H⁺ ions. This causes the amino group to become protonated (-NH3⁺) and the carboxylic acid group to remain in its protonated form (-COOH).
Step 3: Identify the predominant form of proline at pH 2. Since the amino group is protonated and the carboxylic acid group is not deprotonated, the structure will include both -NH3⁺ and -COOH groups.
Step 4: Draw the structure of proline with the correct protonation states. Represent the cyclic structure with the amino group as -NH3⁺ and the carboxylic acid group as -COOH. Ensure the side chain and ring are accurately depicted.
Step 5: Verify the structure. Double-check that the protonation states match the conditions at pH 2 and that the cyclic structure of proline is correctly represented.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
5m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Amino Acid Structure

Amino acids are organic compounds that serve as the building blocks of proteins. Each amino acid has a central carbon atom bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (R group). Proline is unique among amino acids due to its cyclic structure, where the side chain forms a ring with the amino group, affecting its properties and behavior in proteins.
추천 영상:
7:19
Charged Amino Acids

pH and Protonation

pH is a measure of the acidity or basicity of a solution, influencing the protonation state of functional groups in molecules. At low pH (acidic conditions), amino groups can be protonated to form -NH3+, while carboxyl groups can remain in their protonated form (-COOH). Understanding how pH affects the ionization of amino acids is crucial for predicting their predominant forms in different environments.
추천 영상:
01:46
Why we use pKa instead of pH.

Zwitterion Formation

A zwitterion is a molecule that has both positive and negative charges, resulting in an overall neutral charge. In the case of proline at physiological pH, it exists predominantly as a zwitterion, where the amino group is protonated (-NH3+) and the carboxyl group is deprotonated (-COO-). This dual charge state is important for the solubility and reactivity of amino acids in biological systems.
추천 영상:
04:41
Why Amino Acids Exist as Zwitterions