Structure of proteins I

Question 1

functions of proteins

Answer 1

catalyst for reactions
regulate gene transciption
mediatory of immune response
components of CT

Question 2

what are the structure and function of a protein determined by

Answer 2

amino acid sequence of its polypeptide chain

Question 3

feature of alpha-amino acid

Answer 3

central alpha-carbon

alpha carbon is asymmetric (except glycine)

Question 4

what type of amino acids are found in mamalian proteins

Answer 4

L-amino acids

Question 5

what amino acid is a secondary amine

Answer 5

proline

Question 6

what groups is an alpha carbon covalently bound to

Answer 6

alpha amine
alpha carboxylic acid
hydrogen
R group

Question 7

what gives each amino acid its unique chemical and physical properties

Answer 7

the R group

Question 8

zwitterion

Answer 8

molecule having both positive and negative charges

Question 9

what are the non polar aliphatic amino acids

Answer 9

glycine, alanine, valine, leucine, isoleucine, methionine, proline

Question 10

where are the non-polar aliphatic amino acids typically found

Answer 10

in interior of globular proteins

Question 11

what is unique about methionine

Answer 11

contains sulfur

Question 12

what are the aromatic amino acids

Answer 12

phenyalanine
tyrosine
tryptophan

Question 13

what type of property do aromtic amino acids ahve

Answer 13

hydrophobic

Question 14

why does tyrosine ahve soem polarity

Answer 14

because of the OH group

Question 15

why is tryptophan slightly polar

Answer 15

ring nitrogen

Question 16

what are the pola runcharged amino acids

Answer 16

serine
threonine
cysterin
asparagine
glutamine

Question 17

where are the polar, uncharged amino acids found

Answer 17

interior and exterior of proteins

Question 18

what do polar, uncharged amino acids readily form

Answer 18

hydrogen bonds

Question 19

what is unqiue about cysteine

Answer 19

contains sulfur, readily forms disulfie bridges

Question 20

the hydroxyl groups of serine and threonine serve as what

Answer 20

phosphate acceptors in protein kinase reactions

Question 21

what are the amino acids with ionizable side chains

Answer 21

aspartate gluatmate

Question 22

what are asp adn glu considered to be

Answer 22

acidic amino acids

Question 23

what are the basic amino acids

Answer 23

lysine, arginine, histidine

Question 24

what carries a negative charge at physiological pH

Answer 24

asp adn glu

Question 25

what carries a postive charge at physiological pH

Answer 25

arg and lys

Question 26

what type of charge does histidine carry at physiological pH

Answer 26

can be positive or uncharged

Question 27

peptide bonds

Answer 27

linkages that connect amino acids to form polypeptide chains

Question 28

what are peptide bonds formed by

Answer 28

dehydration reaction

Question 29

what is the confirmation of a peptide bond

Answer 29

planar

Question 30

what is the primary structure of a protein

Answer 30

amino acid sequency

Question 31

what are the ends of a polypeptide chain

Answer 31

free amino group, free carbosylate group

Question 32

how are peptide sequences written

Answer 32

from N terminus to C terminus

Question 33

What are 2 ways we can view protein structures

Answer 33

X ray cystrallography and NMR spectroscopy

Question 34

what is the secondary protein structure

Answer 34

alpha helicies, and beta pleated sheets

Question 35

what is the structure of an alpha helix

Answer 35

clockwise spiral
each C=O is hydrogen bonding to H-N group 4 amino acid residues down
each turn contains 3.5 amino acid residues

Question 36

what hinders helix formation

Answer 36

proline
large buly side chains
multiple side chians of like charge

Question 37

what amino acids are often found in alpha helices

Answer 37

alanine, leucine, methionine