Biology / Unit 1: The Science of Biology and Chemistry of Life
1.5 Proteins and Nucleic Acids
Notes
Proteins and nucleic acids are the other two major macromolecules.
- Proteins are made of amino acids (20 kinds) joined by peptide bonds. They contain C, H, O and N.
- The order of amino acids decides how a protein folds, and its shape decides its job.
- Protein jobs: enzymes, structure (keratin, collagen), transport (hemoglobin), movement (muscle), defense (antibodies), signals (some hormones).
- Nucleic acids (DNA and RNA) store and transmit genetic information. Their monomers are nucleotides.
- A nucleotide has a sugar, a phosphate group, and a nitrogen base.
Practice
A molecule contains nitrogen and is built from 20 different kinds of monomers. It is most likely a:
Proteins are built from 20 kinds of amino acids.
What are the three parts of a nucleotide?
Every DNA or RNA nucleotide has these three parts.
Hemoglobin carries oxygen in red blood cells. If its shape changes, what is most likely to happen?
A protein's shape determines its function.
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