biological molecules

All amino acids have the same basic structure.Differnet R-groups result in different amino acids./

Amino acids join when the amine and carboxylic group connected to central carbon atoms react. OH from carboxlic group-H amine group. A peptide bond is formed between the amino acids and water is produced (condesation reaction). Dipeptide formed.

Multiple peptide bonds=polypeptide. Reaction catalysed by enzyme Peptidyl transferase, from ribosomes.

Interactions of R-groups form bonds and complex structures.          Rf=distance travelled by component/distrance travelled by solvent

Primary-The sequence in which amino acids are joined, directed by information carried in the dna. Only Peptide bonds present. Order can affect final structure.

Secondary-The O,H,N atoms of the basic repeating structure of the amino acids interact (no R-group interactions). Hydrogren bonds may form between the chain, causing a coil (Alpha helix). Can also lay parallel joined by hydgrogen bonds, forming sheet like strrcutures (Beta pleeted sheets).

Teritary- folding protien into final shape. The secondary structure brings R-groups closer together, until they are close enought to interac, further folding these sections.The following interactions of R-groups will occur:

Hydrophobic/hydrophillic: weak interactions between non polar and polar R-groups 

Hydrogen bonds: weakest bond formed

ionic bonds: stronger the H bonds, oppositley charged R-groups

Disulfide bonds(disulfise bridgest): covalent/strongest bond, only between R-groups containing sulfur