PROTEINS

Characteristics of Proteins Contain carbon, hydrogen, oxygen, and nitrogen Serve as structural components of animals in growth, maintenance and repair Also can serve as control molecules (enzymes) inside organisms Also can as transport and messenger molecules The basic building block of proteins are the amino acids (total of 20 of these)

Amino Acid Amino group gives AA its amino properties. Carboxyl group acts like an acid, and give it its acid properties “R” group varies between each of the 20 AA’s. This is what makes each of the AA’s different and unique. Two amino acids join together to form a dipeptide, the spot where they join is called a peptide bond Most proteins are know as polypeptides, because they are long chains of AA’s.

Amino Acids Structures-AA’s usually end in “ine”

Some More Amino Acids

Still More Amino Acids

Formation of a Dipeptide Dehydration synthesis

Amino Acid + Amino Acid = Dipeptide 3 amino acids linked = Tripeptide 100’s of AA’s linked = Polypeptide

A protein consists of one or more polypeptide chains.

Enzymes a very important protein molecule These are polypeptides that regulate the chemical reactions in all living things. Enzymes control the rate of reactions and lower the activation energy to get reactions started without being used up or altered in the reaction.