Biology unit 5.4: proteins

What is a protein?

Polymer constructed from a set of just 20 kinds of monomers called Amino acids.

What are functions of proteins?

They from structures such as hair and fur, make up muscles and provide long-term nutrition storage. They also defend the body from harmful bacteria, and others that act as signals to transform messages from cell to cell.

Explain amino acids

Each amino acid monomer consists of a central carbon atom bonded to four partners, three of them being the same in every amino acid.

What are the central carbon’s partners?

One of them is hydrogen, two are carboxyl group and one other is the amino group

What makes the difference in each type of amino acid?

The side group that attaches to the fourth bond of the central carbon.

Give examples of amino acids being different

For example, the side group of amino acid Leucine is a hydrocarbon so the Leucine region is hydrophobic however the side group of the amino acid Serine is a hydroxyl group that is hydrophilic

What is a polypeptide?

Cells create proteins by linking amino acids together into a chain called a polypeptide

How is each chain produced?

By a dehydration reaction between the carboxyl group of one amino acid and the amino group of another

How long are polypeptide chains?

each one is at least 100 amino acids long

Explain the shape of a function protein

consists of one of more polypeptide precisely folded and coiled into unique shapes

What can change the protein’s shape?

surrounding environments, usually being aqueous.various factors such as pH,and temperature affect the shape of the protein

Explain denaturation

When unfavorable factors such as change in the temperature, pH or some other changes may change the quality of the protein and will untie the polymer chain of the protein

Example of denaturation

when you’re frying an egg, the egg white turns from a liquid to a hard solid as the polypeptide chain becomes tangled with one another