26.2. Amino Acids and Proteins http://www.ck12.org
FIGURE 26.10
Sickling in red cells due to presence of
hemoglobin S.
Lesson Summary
- Amino acids contain both a carboxylic acid group and an amine group.
- Proteins are formed by the linkage of amino acids with amide (peptide) bonds.
- There are four levels of protein structure: primary, secondary, tertiary, and quaternary.
- Proteins serve numerous functions in the body, including structural support, catalysis, and molecular trans-
portation. - Enzymes catalyze biochemical reactions.
- Enzymes are classified by the types of reactions that they catalyze.
- Hemoglobin is a protein containing four subunits that transports oxygen throughout the body.
- In sickle-cell disease, an abnormal hemoglobin structure causes aggregation (clumping) of that protein, which