Macromolecules

Protein

Proteins• Probably the most

diverse group of macromolecules is the proteins.

Proteins• Proteins are

complex polymers composed of C, H, O and N.

• Polymer : large molecule formed when many smaller molecules bond together

Proteins• The building blocks

of proteins are smaller molecules called amino acids held together by peptide bonds

• Most end in “-ine”• Despite the wide

variety of life on Earth, all living organisms use only 20 different amino acids to produce the proteins they require

Proteins• Green plants can

make all 20 essential amino acids on their own; animals cannot. Thus, animals, including humans, must get some of these essential amino acids from the foods they eat.

Proteins• Enzymes are

important proteins found in living things.

• An enzyme changes the rate of a chemical reaction.

• Enzymes are involved in nearly all metabolic reactions

• Usually end in “-ase”

Proteins• Substrate- Component in an enzyme reaction• Enzyme reactions take place in the active site • Substrate + Enzyme Product + Enzyme• The enzyme is unchanged in the reaction.

Proteins• Each enzyme is

specific to only one reaction.

• This reaction is often compared to a lock and key.