Chapter 5.4 Summary

• protein is a polymer constructed from a set of just 20 kinds of monomers called amino acids
• proteins with less-visible functions include proteins that circulate in the blood and defend the body from harmful microorganisms
  
  
  

• amino acid monomer consists of a central carbon atom bonded to four partners: hydrogen atoms, carboxl grup, amino group, and functional group
• the side group (R-group) is responsible for the particular chemical properties of each amino acids
• cells create proteins by linking amino acids together into a chain called polypeptide
  
• proteins are composed of one or more polypeptide chains
• our body can make various proteins by arranging the amino acids in different order
• 20 letters of amino acids
• most polypeptide chains are at least 100 amino acids in length
• a functional protein consists of one or more polypeptides precisely twisted, folded, and coiled in a unique way
• protein's shape is influenced in the surrounding enviornment
• the change in temperature, pH, or some other enviornment change can change protein's shape
• protein's function depends on shape

Concept Check 5.4

1. Give at least two examples of proteins you can "see" in the world around you. What are their functions?

The two examples of proteins I can "see" in the world around are texture of an animal's coat and the muscles of an animal. Their function is to give texture and muscles to an animal.

2. Relate amino acids, polypeptides, and proteins.

A protein is a polmer constructed from a set of 20kinds of monomers called amino acids. However, the proteins are created by linking the amino acids into a chain called polypeptide.

3. Explain how heat can destroy a protein.

Heat can destroy a protein because heat unfolds the protein. This process is called denaturation. So, there is not much force to maintain the folding between pairs of side groups. Since a protein's function depends on the shape, a protein that becomes denatured and loses shape, it would lose it's ability too.

4. Which parts of an amino acid's structure are the same in all amino acids? Which part is unique?

The parts of an amino acid's structure are the amino group, caboxl group, and a hydrogen atom. The part that are unique is the side group. The side group, also called "R-group", is responsible for the particular chemical properties of each amino acids.