List an example of each of the four classes polymers that living things make and use
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The four classes of polymers are:

1. Nucleic acids.  Examples are DNA and RNA

2. Protein. Examples are enzymes and hemoglobin

3. Carbohydrates. Examples as starch and glycogen

4. Lipids. Examples are triglycerides and phospholipids

The building blocks of nucleic acids are called bases and there are four types known as Guanine, Adenine, Thymine and Cytosine.

The building blocks of carbohydrates are glucose molecules.

The building blocks of protein are amino acids.

The building blocks of lipids are a combination of fatty acids and glycerol.

c) up is the direction the magnetic force is acting on the charge.