1.2

Question 1

What kind of amino acids make proteins?

Answer 1

L amino acids

Question 2

What is an L amino acid?

Answer 2

The amino group (NH3) comes before the carboxyl group (coo-)

Question 3

What is the pKa of Lysine and Argentine?

Answer 3

10-12

Question 4

What is the pKA of histidine?

Answer 4

6

Question 5

What is the pKa of aspartic acid and glutamine?

Answer 5

3-4

Question 6

What is a zwitterion? (Ampholyte)

Answer 6

A dipolar ion that acts as an acid or base

Question 7

What does 2 zones of buffer mean in a titration curve?

Answer 7

The amino acid is not charged

Question 8

What does 3 zones of buffer in a titration curve mean?

Answer 8

Look at middle pKa to see which amino acid it is

Question 9

How are peptide bonds made?

Answer 9

Two amino acids join and water is lost to form the bond a

Question 10

Phosphorylation

Answer 10

Adds a phosphate group to Ser, Thr, and Tyr
Enzyme activity

Question 11

Sulfation

Answer 11

Only happens to Tyr
Hormones

Question 12

Methylation

Answer 12

Adds methyl group to Lys or Arg

Question 13

Are cysteine sulfhydryl groups oxidized or reduced?

Answer 13

Oxidized

Question 14

What purpose do disulfide bridges serve?

Answer 14

Helps link amino acid chains together and helps with structure

Question 15

Are the interior of beta barrels hydrophilic or hydrophobic

Answer 15

Hydrophobic

Question 16

How many residues are there per turn in an alpha helix

Answer 16

3.6

Question 17

How many residues are there per turn in a coiled-coil alpha helix

Answer 17

3.5

Question 18

On average how many hydrogen bongs are there per turn in an alpha helix

Answer 18

3 to 4 hydrogen bonds

Question 19

At which end is an alpha helix is the partial positive charge of the overall dipole

Answer 19

Amino end

Question 20

What is the structure of a keratin fiber?

Answer 20

Staggered coiled coil structures that have protofilament, protofibril, and filaments

Question 21

What are the 3 amino acids repeated in the collage helix?

Answer 21

Proline, Glycine, Hydroxyproline

Question 22

Is the collagen helix right handed it left handed?

Answer 22

Left handed

Question 23

What is the difference between an alpha/beta motif and an alpha + beta motif? Which is more common?

Answer 23

Alpha/beta motifs alternate frequently between an alpha and beta strand
-alpha + beta does not alternate frequently
-alpha/beta is more common

Question 24

What is the function of the barrel versus the loops in alpha/beta (TIM) barrel proteins such as RuBisCo or DNA Endonuclease IV

Answer 24

-the barrel is a tightly hydrophobic core
-loops are used for ligand/substrate binding,flexible, orients protein the right way

Question 25

What secondary structure is the EF hand composed of? What molecules do EF hands bind? What are the functions of charged residues vs hydrophobic residues?

Answer 25

-2 alpha helixes separated by a flexible loop
-bind to DNA(short), calcium(long)
-charged/polar located in loop directly interact with ligand
-hydrophobic stabilize structure and properly orient loop for binding

Question 26

What is the structure of neuramindase? What enzymatic activity goes it have? Where is the enzyme active site?

Answer 26

-4 beta propellers
-cleaves off sialic acid bonds which allows for it to infect other cells
-hydrophobic core with loops in between

Question 27

Glycosylation O linked adds to

Answer 27

Serine, threonine, tyrosine

Question 28

Glycosylation N linked adds to

Answer 28

Asparagine

Question 29

Glycosylation C linked

Answer 29

Tryptophan

Question 30

Acetylation adds to

Answer 30

Lysine

Question 31

How to separate proteins by charge?

Answer 31

-Ion exchange chromatography
-Electrophoresis
-negative charge comes out first

Question 32

How to separate by protein size?

Answer 32

-Gel filtration chromatography
-large proteins come out before small proteins

Question 33

How to separate proteins by polarity?

Answer 33

-hydrophobic interaction chromatography/reverse phase
-hydrophilic comes out before hydrophobic