Proteins

Proteins

The most important job of a cell is to make proteins. Proteins are made in the ribosomes of a cell. Protiens are used for almost anything. They have many different structures, with each different structure having a different function. They are also known as multipurpose molecules.






Some examples of proteins are keratin and collagen which makes up hair nails and skin.

Proteins are made of two structures monomers and polymers. Monomers are amino acids, and there are 20 different ones. Polymers are polypeptides. Proteins can be one or more polypeptide chains that are folded and bonded together. They are large and complex molecules.

The structure of amino acids have a central carbon, and amino acid groups. The carboxyl group are acids. The R group is a side chain. This is a variable group confers unique chemical properties of the amino acids.

Nonpolar amino acids are nonpolar and hydrophobic. Nonpolar meaning there are carbons in it. Hydrophobic means that it does not like water so it tends to try and push the water away. On the other hand amino acids can be polar and hydrophilic. By polar it means that it has a nitrogen in it. Hydrophilic means that it likes water and wants to be in or as near as possible to water as it can. They are polar and hydrophilic because they fold in order to make a protein.

Sulfur containing amino acids allow a link between sulfers and amino acids to be created called disulfide bridges. It smells like rotten eggs or permed hair.

Peptide bonda are building proteins that link the NH2 of one amino acid to COOH of another. Part of the buildin proteins are polypeptide chains that involve N-terminus= NH2 end and the C- terminus which ends in a COOH.


One of the four levels of structure is primary (1 degree) stucture pattern. The DNA of the gene decides the amino acid sequence and even a slight change in the sequence can make it a change in the protein's stucture and funtion. The perfect example of this is Sickle Cell Anemia, where the structure of the cell of hemoglobin goes from a 'doughnut' shape to one that looks like a 'sickle' or 'cresant moon'.