Protein Structure Study Guide

What are 3 parts of an amino acid

Amino acid group, carboxyl groups, and R Group

What makes one amino acid different from another is its R-group (side chain).

All amino acids have the same basic structure, but the R-group is different. The R-group (side chain) makes each amino acid different.

What do we call proteins that are spherical in shape?

Globular proteins

What do we call proteins that are shaped like long fibers

fibrous proteins

What are 4 levels of a protein structure

Primary, Secondary, tertiary, and quaternary

What is a primary structure

A chain of amino acids chained together holds together by peptide bonds between amino acids

What is secondary structure

The amino acid chain folds into shapes. The two shapes are alpha helix (spiral) and beta pleated (folded)

What is a tertiary structure

The protein folds even more into a 3D shape. Folds more because of interactions with the amino acid R groups (side chains)

What is a quaternary structure

Two or more protein chains folded together

What happens when a protein is denatured?

protein loses its shape and function.

What factors can cause a protein to denature?

heat, pH changes, and chemicals can cause the protein to lose its shape and stop working

Why does meat change color when it is cooked?

Heat changes the protein's shape, making meat change color.

explain how a mutation can be silent

DNA changes, but the amino acid stays the same.

Missense mutation

A DNA change that causes one amino acid in a protein to be replaced with a different amino acid.

nonsense mutation

DNA change that causes an early stop, making a shorter protein.

Frameshift mutation

Nucleotides are either inserted or deleted causing a number not divisible by three