lecture 6 part 2

Question 1

what determines function of protein

Answer 1

structure

Question 2

what is the unique 3D folding of a protein detemrined by

Answer 2

amino acid sequence

Question 3

what dictates molecular interactions of each amino acid

Answer 3

chem properties of the side chain

Question 4

Vast majority of molecular interactions with amino acids are covalent or non covalent?

Answer 4

non covlaent

Question 5

what join amino acids together

Answer 5

peptide bonds

Question 6

how are peptide bonds formed

Answer 6

by dehydration rxn

Question 7

where is the covalent bond of the amino acid

Answer 7

between carbon in carboxyl group of last amino acid and the nitrogen on the amino group of the incoming amino acid

Question 8

what is peptide bond formation catalyzed by

Answer 8

ribosomes within a cell (ribosomes conduct dehydration rxn to form new proteins)

Question 9

peptide

Answer 9

a few amino acids joined together

Question 10

polypeptide

Answer 10

many amino acids joined together

Question 11

what splits peptide bond

Answer 11

hydrolysis rxn

Question 12

four levels of protein structure

Answer 12

1)primary structure
2)secondary structure
3)tertiary structure
4)quaternary structure

Question 13

primary structure

Answer 13

-our polypeptide chain/sequence of amino acids -sequence begins at free amino end and is read to the carboxyl end

Question 14

secondary structure

Answer 14

-protein folding involving portions or segments of a polypeptide chain
-two major types 1)alpha helix 2) beta-sheets
-due to hydrogen bonding by atoms in the peptide backbone secondary structure is held together
-nitrogen of amino group and the oxygen with a double bond to carbon are binding to each other
-side chains are not involved
-in both alpha helices and beta sheets, side chains face outward from the backbone
-when side chains face outward, they can interact with other parts of the folded protein or other molecules

Question 15

tertiary structure

Answer 15

-overall folding of 3D conformation of a single polypeptide chain
-bonding by side groups are important for tertiary structure

Question 16

bonds important for holding tertiary strcture in its shape are

Answer 16

-hydrophobic interactions
-van der waals forces
-hydrogen bonding
-disulfide bridge
-ionic bond
-polypeptide backbone
(most of the bonds holding a protein in its 3D shape are noncovalent)

Question 17

where do hydrophobic side chains tend to be buried

Answer 17

inside a folded protein and the hydrophilic ones face outward

Question 18

some proteins are composed of

Answer 18

a single folded polypeptide chain and others are composed of two or more polypeptide chains folded together into a final structure

Question 19

example of protein composed of a single folded polypeptide chain

Answer 19

myglobin

Question 20

example of protein composed of two or more polypeptide chains folded together into final structure

Answer 20

collagen

Question 21

Quaternary structure

Answer 21

-2 or more polypeptide chains folding together to make a functional product protein

Question 22

example of quaternary structure are

Answer 22

hemoglobin and antibodies

Question 23

subunits

Answer 23

one poly peptide chain that is in a protein with quaternary structure