Question

what are the levels of protein structure and what role do functional groups play? why? proteins accomplish many cellular tasks such as facilitating chemical reactions, providing structure, and carrying information from one cell to another. how a protein chain coils up and folds determines its three - dimensional shape. its shape will, in turn, determine how it interacts with other molecules and thus performs its function in the cell. model 1 - formation of a peptide bond amino acid 1 amino acid 2 dipeptide 1. examine the amino acids in model 1. a. circle an amine group in the diagram. b. draw a triangle around a carboxylic acid (carboxyl) group. 2. how are the amino acids similar to one another? 3. how are the amino acids different from one another?

Explanation:

Step1: Identify amine group

An amine group is -NH₂. In the amino - acid structures, it is present as -NH₂ or -NH₃⁺ (in acidic conditions). In the given amino - acid diagrams, the -NH₂ group can be circled.

Step2: Identify carboxyl group

A carboxyl group is -COOH. In the amino - acid structures, it is present as -COOH or -COO⁻ (in basic conditions). A triangle can be drawn around the -COOH group in the diagrams.

Step3: Analyze similarities

All amino acids have a central carbon atom (alpha - carbon) bonded to an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a side - chain (R - group). The basic structure of having an amino and a carboxyl group attached to the same carbon is common among all amino acids.

Step4: Analyze differences

The main difference between amino acids lies in their R - groups. The R - groups can be non - polar, polar uncharged, polar charged (acidic or basic), and have different chemical properties and sizes, which gives each amino acid its unique characteristics.

Answer:

1.

• a. Circle the -NH₂ group in the amino - acid structures.
• b. Draw a triangle around the -COOH group in the amino - acid structures.

1. All amino acids have a central carbon bonded to an amino group, a carboxyl group, a hydrogen, and an R - group.
2. Amino acids differ in their R - groups, which can have different chemical properties and sizes.