Amino Acids and Proteins

Question 1

structural or mechanical roles, polypeptides are intertwined to form cables or fibers

Answer 1

fibrous proeins

Question 2

are functional or nonstructural, chains folded on itself to give compact rounded structure and are water soluble

Answer 2

globular proteins

Question 3

aspartate is

Answer 3

acidic amino acid

Question 4

glutamate is

Answer 4

acidic amino acid

Question 5

arginine

Answer 5

basic

Question 6

lysine

Answer 6

basic

Question 7

histidine

Answer 7

basic

Question 8

nonpolar

Answer 8

glycine, alanine, leucine and phenylalanine

Question 9

serine, cysteine, threonine and tyrosine

Answer 9

neutral

Question 10

glycine, alanine, leucine and phenylalanine

Answer 10

nonpolar

Question 11

what forms of amino acid are found in humans

Answer 11

L forms

Question 12

sulfur containing amino acids

Answer 12

methioine and cysteine

Question 13

aromatic compounds

Answer 13

phenylalanine, tyrosine, and tryptophan

Question 14

nonpolar

Answer 14

glycine, alanine, proline, valine, leucine, and isoleucine

Question 15

polar

Answer 15

asparagine, glutamine, serine and threonine

Question 16

2 cysteins can spontaneously oxidize to produce

Answer 16

cystine via a disulfide bridge

Question 17

__________is a genetic disease resulting in defective transport protein that reabsorbs cystine into renal tubular cells and apppears in urine and forms calculi

Answer 17

cystinuria

Question 18

_______is the sequence of amino acids in a polypeptide chain

Answer 18

primary structure

Question 19

peptide bond is

Answer 19

carboxyl end and amino acid

Question 20

__________is the folding or coiling of the chain to give regular repeated motifs

Answer 20

secondary structure

Question 21

intramolecular H-bonding

Answer 21

between different parts of the same chain

Question 22

intermolecular H bondingq

Answer 22

between different chains

Question 23

how are secondary structures stabilized

Answer 23

stabilized by hydrogen bonds formed between the carbonyl oxygen of one peptide bond and the amino hydrogen of another

Question 24

intermoleclar hydrogen bonding and intramolecular hydrogen bonding

Answer 24

beta pleated sheet

Question 25

intramolecular hydrogen bonding

Answer 25

alpha helix

Question 26

____________secondary structures is strong, non-elastic and flexible

Answer 26

beta pleated sheat

Question 27

strong and may be elastic type of secondary structure

Answer 27

alpha helix

Question 28

_______are strong rope like strucutres of intertwised alpha helices which are a major component of external protective layers in mammals

Answer 28

keratins

Question 29

_______have high sulfur content and many S-S bonds

Answer 29

hard keratins

Question 30

_______have low sulfur content and few S-S bonds between the chains

Answer 30

soft keratins

Question 31

___________are a family of extracellular glycoproteins and are a major protein of connective tissue and forms insolbule fibers of great strength

Answer 31

collagnes

Question 32

composition of collagens

Answer 32

rigid, cross linked triple helical rods

Question 33

collagen has a high content of

Answer 33

glycine, proline, hydroxyproline and lysine

Question 34

what two amino acids confer collagens rigidity

Answer 34

pro and hyp

Question 35

what is the fundamental unit of collagen

Answer 35

tropocollagen

Question 36

____________is a triple helical rod that is rigid and has a wider pitch than alpha helix to accomodate the bulky pro and hyp residues

Answer 36

collagen

Question 37

________-is the modification of a structure after synthesis of the poypeptide chain

Answer 37

post-translational modification

Question 38

_______ and ________ residues are hydroxylated

Answer 38

pro and lys

Question 39

hydroxylated pro forms

Answer 39

h bonds between chains

Question 40

hydroxylated lys forms

Answer 40

covalent bonds between chains

Question 41

pro and lys residues become hydroxylated reuiqres

Answer 41

vitamin C

Question 42

the collagen in tendons are arranged as

Answer 42

parallel bundles

Question 43

the collagen in skin are arranged in

Answer 43

sheets of fibrils lyaered at many angles

Question 44

the collagen in cartilage has

Answer 44

no distinct arrangement

Question 45

cornea collagen is

Answer 45

planar sheats stacked corssways to minimize light scatter

Question 46

_________is the overall 3d structure of the folded peptide

Answer 46

tertiary structure

Question 47

globular proteins fold during and following synthesis along the same principles as

Answer 47

micell formation

Question 48

what are some forces that can stabilize structures of globular proteins

Answer 48

electrostatic attractions hydrogen bonds hydrophobic interactions disulfide bonds

Question 49

________assist in protein folding by slowing it down to prevent inapprorpiate interactions

Answer 49

molecular chaperones

Question 50

_____________are protein conformational diseases caused by misfolded proteins

Answer 50

prion diseases

Question 51

what protein structure is messed up in prion diseases

Answer 51

tertiary structure

Question 52

_____________are domains that are physically independent regions within the overall tertiary structure of a large complex protein

Answer 52

structural domains

Question 53

polymorphisms, protein families isoforms, and developmental variation are all examples of

Answer 53

variations in primary structure

Question 54

_____________ are variations in primary structure of 2 or more alleles may be silent some have a profound effect

Answer 54

polymorphisms

Question 55

_________-are proteins with simila but NOT identical structure and function that have evolved from the same ancestral protein; sequences very similar

Answer 55

protein families

Question 56

examples of protein families

Answer 56

hemoglobin chains, myoglobin serine proteases

Question 57

_____________perform essentially the same function and are highly homologus and evolved from the same ancestral gene possess different amino acid sequences and physico-chemical properties

Answer 57

protein isoforms

Question 58

___________are different isoforms that are expressed during different stages of development

Answer 58

developmental variation

Question 59

__________are highly similar sequences that evolved from the same ancestor

Answer 59

homologs

Question 60

____________are from different species but orignated from same gene in ca common ancestor and normally retain same function

Answer 60

orthologs

Question 61

example of orthologs

Answer 61

human bovine and procine insulin

Question 62

___________from same species, originated from common ancestral gene, have different functions ( myogloin and different hemoglobin chains)

Answer 62

paralogs

Question 63

fetal hb have what structure

Answer 63

alpha 2 gamma 2

Question 64

adult hb have what structure

Answer 64

alpha 2 beta 2 or alpha 2 delta 2

Question 65

gower I

Answer 65

zeta 2 epsiolon 2

Question 66

gower II

Answer 66

alpha 2 epsiolon 2

Question 67

protalnd I

Answer 67

zeta 2 gamma 2

Question 68

________is the aggregation of an interaction between subunits in a multimeric protein

Answer 68

quatenary structure

Question 69

human hemoglobin differences are examples of

Answer 69

paralogs

Question 70

does myoglobin have a higher or lower affinity for oxygen

Answer 70

myoglobin

Question 71

in the absence of oxygen hemoglobin is predominantly in the

Answer 71

T state

Question 72

when oxygen binds all four subunits change to the ________ state

Answer 72

R state

Question 73

binding of myoglobin is

Answer 73

noncooperative so graph is hyperbolic

Question 74

at a lower pH Hb has a

Answer 74

less affinity for the oxygen

Question 75

fetal red blood cells have

Answer 75

higher affinity for oxygen than maternal RBC's

Question 76

2,3 BPG and carbon dioxide both

Answer 76

decrease hb affinity for oxygen

Question 77

when proteins denature the structures is lost but

Answer 77

primary structure remains in intact