Amino acids Flashcards
What different types of proteins are there?
Structural, signalling, enzymes, antibodies, receptors
How can enzymes be used in biochem?
Can detect specific proteins through techniques of: Western blotting; Enzyme linked immunosorbent assay
What are the roles of receptors?
Bind to molecules which send signals to cell (insulin receptor); allow molecules to enter cell (CD36); detect changes in surrounding environment (mechanoreceptors detect changes in blood pressure and flow)
How can proteins be identified?
Centrifugation then gel electrophoresis; comparison of different samples allows determination of changes in protein level and interaction
What characteristics of a sample can assessed in comparison?
Concentration in a sample; types of proteins present; functions of proteins
How many amino acids are there?
20
How can amino acids be classified by structure?
Non-polar aliphatic; aromatic; non-polar; polar uncharged, negatively charge; positively charged; non-charged N-containing; hyroxyl-containing; S-containing
What are amino acids that are key to polypeptide structure and function?
Cystein forms disulfide bonds; serine is most commonly phosphorylated amino acid; methionine is always the first amino acid
What is the primary structure?
Chain of amino acids; read from N- to C- terminus (NH2 end to COOH end)
What is the secondary structure?
Folding of polypeptide chain; formed of H bonds
What are two types of secondary structure?
alpha-helix and beta-pleated sheet
What are the characteristics of alpha helix?
H bond each 4th amino acid between C=O and N-H; 3.6 amino acid resides/turn
What is an example of an alpha helix?
Myogoblin
What are the characteristic of beta pleated sheet?
H bond form between peptide bonds; either parallel (between different chains) or anti-parallel (between same chain); multiple sheets provide stability
What is an example of beta pleated sheet?
Silk fibroin
