Summary of Concept 5.4

Concept 5.4

Notes

• Proteins are polymer constructed from monomers called amino acids.
• Amino acids are monomers made of one carbon bonded to four other groups.
• Polypeptides are amino acid chains.
• There are 20 different kinds of amino acids, and can be combined in many different ways to form different proteins.
• Proteins are put together in special ways, therefore resulting in different shapes of proteins.
• Hydrophilic amino acids stay on the outside of proteins, while hydrophobic amino acids stay on the inside.
• Protein denaturates (loses its shape due to a change in temperature, pH, or other environmental qualities).

Concept Check

1. Give at least two examples of a protein you can "see" in the world around you. What are their functions?
Nuts have many proteins in them, and they feed animals such as chipmunks and squirrels. Muscles also have protein in them, resulting in animals being able to move (and being able to provide nutritious protein through their meat).

2. Relate amino acids, polypeptides, and proteins.
Amino acids are the monomers that make up polypeptides, polypeptides make up proteins, and proteins make up organisms.

3. Explain how heat can destroy a protein.
Heat can destroy a protein through the process of denaturation, in which the protein unravels due to outside environmental changes (in this case, heat). It unfolds the proteins' polypeptides, meaning the protein is no longer a protein, but rather, several groups of polypeptides.

4. Which parts of an amino acid's structure are the same in all amino acids? What part is unique?
In all amino acids, there is a carbon atom in the middle of the molecule, but what surrounds it is what makes amino acids different from one another.