Proteins

What are proteins? Contain the elements C, H, O and N Nitrogen gives the protein its specific characteristics as a protein The main function of protein is to provide body with materials for building and repairing body tissues

Structure of Protein Proteins are made of smaller building blocks called amino acid There are only 20 amino acids used to make proteins in our body, they can create unlimited combinations of proteins

Structure of Amino acid

Basic Structure of Amino Acid All amino acids have the ending -ine All amino acids have carboxyl group (contains COOH or COO-) All amino acids have amino group (contains NH2 or NH3 +

Basic Structure of Amino Acid The only difference between amino acids is their R group or Variable group The R group gives each amino acid its specific, individual traits

Structure of Amino acid

Can you identify the carboxyl group, the amino group, the R group and the central carbon?

Proteins Proteins are made of multiple amino acids linked together To link 2 amino acids, a peptide bond is formed

Formation of peptide bond Proteins are formed by joining the carboxyl group of one amino acid to the amino group of another amino acid. The bond formed between two amino acids is called a peptide bond

Peptide bond Peptide bonds are always between NH and C=O

Where are the peptide bonds?

Classification of Proteins Dipeptide: 2 amino acids joined by a peptide bond Tripeptide: Polypeptide:

This procedure is called dehydration synthesis

Peptide Bond Break Down If polypeptide can be formed through Dehydration synthesis, then polypeptide can be broken by ________________________

Amino Acids Each amino acid is different Some “like” water: they will dissolve in it They are called: Hydrophilic Amino Acids Some “fear” water: they will separate from it They are called: Hydrophobic Amino Acids

Protein Folding

It’s the SHAPE that matters! Proteins do their jobs, because of their shape Unfolding a protein destroys its shape wrong shape = can’t do its job unfolding proteins = “denature” Factors that affect proteins’ shape: temperature pH (acidity) unfolded “denatured” folded

Protein Levels of Organization Primary Structure: the linear sequence of amino acids in a protein chain Secondary Structure: the folding or coiling of the protein chain Tertiary Structure: the actual 3D shape of the protein Quaternary Structure: a complex of 3D shaped proteins joined together