Proteins are large polymers comprimised of long chains of amino acids. The properties of proteins give them a variety of functions:
- They form structural components of animals in particular. For example muscles are made of protein.
- Their tendency to adopt specific shapes makes proteins important as enzymes, antibodies and some hormones.
- Membranes have protein constituents that act as carriers and pores for active transport across the membrane and facilitated diffusion
Both plants and animals need amino acids to make proteins. Animals can make some amino acids, but must ingest the others (called essential amino acids). Plants can make all the amino acids they need, but only if they can access fixed nitrogen (such as nitrate).
Structure of amino acids
Amino acids: monomers of all proteins, and all amino acids have the same basic structure.
Each amino acid contains the elements carbon, hydrogen, oxygen and nitrogen. Some amino acids contain sulfur.
There are over 500 different amino acids, but only 20 of them are proteinogenic, which…