UNE BIOCHEM 1005 WEEK 1 QUESTIONS WITH CORRECT ANSWERS.

UNE BIOCHEM 1005 WEEK 1 QUESTIONS WITH CORRECT ANSWERS. What are the four different protein structures? 1. Primary 2. Secondary 3. Tertiary 4. Quaternary What is the primary structure of a protein? a linear sequence of amino acids in polypeptide chains which is written from the amino terminus (N-terminus) to the carboxyl terminus (C-terminus) What is the secondary structure made of? a-helix, b-sheets, and bends, turns, or loops How are alpha helices formed? They are formed when the carbonyl group of peptide bonds form a hydrogen bond with the amide hydrogen located 4 residues down the chain. Approximately how much of all secondary structures are a-helices? 1/3 What is not typically found in secondary structures and why? Proline, because it forms a non-traditional peptide bond and adds a "kink" in the helix How are beta sheets formed? They are formed when beta strands are connected laterally by at least two or three backbone hydrogen bonds How are the b-strands connected and and by what? They are horizontally by hydrogen bonds formed between C=O groups of either strand and NH groups of either strand B-sheets can either be _____________ or _________________. parallel or anti-parallel Where does the R group always protrude to? The top or bottom Depending on the R