LAB 1

Question 1

what is the order of the conversion of units

Answer 1

nano - n
micro - μ
milli - m
no prefix
kilo - k

Question 2

how do you go from a smaller to a bigger number

Answer 2

divide by 1000

Question 3

how do you go from a bigger to a smaller number

Answer 3

multiply by 1000

Question 4

what are pipettes

Answer 4

precision instruments that can accurately measure liquid volumes in the microliter range

Question 5

what is the volume adjustment wheel

Answer 5

is used to set the volume that the pipette will despense

Question 6

what is the volume display window

Answer 6

the volume that will be delivered is shown here in 3 numbers

Question 7

what is the volume range

Answer 7

the range of volume a pipette can accurately measure is shown on top of its plunger button

Question 8

what is the measurement error rate if the maximum volume of the pipettes we use in BIOC 192

Answer 8

~1%

Question 9

why are solutions diluted

Answer 9

solutions are often too strong (concentrated) to be analyzed accurately, so they have to be diluted to a weaker concentration before analysis

Question 10

what is the dilution factor

Answer 10

how much a solution is diluted

Question 11

what will the dilution factor depend on

Answer 11

will depend on how concentrated the initial solution is

Question 12

what is the equation for DF when you know the volume of your solution

Answer 12

DF = final total volume/volume of undiluted solution

Question 13

what is the equation for DF when you know the concentration of your solution

Answer 13

DF = undiluted concentration/diluted concentration

Question 14

what formula can you use when you don’t know the dilution factor

Answer 14

c1 * v1 = c2 * v2

Question 15

what happens to denatured proteins

Answer 15

they lose their native structure and therefore cannot carry out their function

Question 16

how can the making and breaking of bonds cause disruption if that is how proteins are regulated

Answer 16

ABNORMAL disruptions of even a small number of bonds can result in a denatured, no functional protein

Question 17

what did Anfinsen’s experiment with ribonuclease show

Answer 17

that proteins can be unfolded (denatured) and refolded (to their native conformation) by changing the environment of the protein

Question 18

how can factors and environmental conditions affect protein folding

Answer 18

factors can lead to protein unfolding decrease the strength of the bonds that stabilize folded proteins

Question 19

what is the changes in structure associated with

Answer 19

gain (folded) and loss (unfolded) of protein function

Question 20

what factors can affect protein structure and stability

Answer 20

heat, pH and ionic strength

Question 21

how does heating the protein affect the protein

Answer 21

heating a protein will increase the kinetic energy of the proteins’ molecules. when enough heat energy is added to molecules they start to rapidly vibrate. this causes any weaker, non covalent interaction to be disrupted. the breaking of non covalent interactions in a protein can be destabilize the structure and cause the protein to denature

Question 22

how can denaturing be cause by pH changes

Answer 22

the ionization states of ionizable amino acid side chain can change as a function of pH, resulting in denaturation of the protein structure in more acidic or basic conditions. at low pH, ionizable amino acid side chain become protonated, while at high pH they become deprotonated. pH induced alteration of the ionization status of a protein will result in the disruption of non covalent interaction hat would normally stabilize the protein fold

Question 23

what is salivary (alpha) amylase

Answer 23

is an enzyme that breaks down carbohydrates in the mouth, digesting starch

Question 24

what happens to the salivary amylase once it reaches the stomach

Answer 24

when food is consumed a strong acid (HCl) is release into the stomach, reducing the stomach pH from ~5.5 pre-food to below 3. this leads to the unfolding and inactivation of salivary amylase as it enters the stomach.

Question 25

which enzyme continues the digestion of starch when it reaches the small intestine

Answer 25

pancreatic amylase

Question 26

what is the primary structure of salivary amylase

Answer 26

a monomeric protein whose single polypeptide chain comprises of 496 amino acid residues

Question 27

what is the secondary structure of salivary amylase

Answer 27

includes a total of 20 alpha helices and 42 beta strands

Question 28

how many domains does salivary amylase have

Answer 28

3 domains a, b and c

Question 29

what is the structure of the A domain in salivary amylase

Answer 29

has a beta/alpha barrel structure made up of 8 antiparallel beta strands surrounded by 8 alpha helices it contains the active site, which includes 2 important ions Cl and Ca

Question 30

what is the structure of the B domain in salivary amylase

Answer 30

forms a open loop with several helices

Question 31

what is the structure of the C domain in salivary amylase

Answer 31

has a Greek key type structure

Question 32

what stabilizes the 2ndary structure of salivary amylase

Answer 32

non covalent interactions

Question 33

what stabilizes the tertiary structure of salivary amylase

Answer 33

is stabilized by 5 disulfide bonds

Question 34

what is starch

Answer 34

a carbohydrate found in plants

Question 35

what is the structure of starch

Answer 35

it consists of 2 different types of polysaccharides that form 2 different structural arrangements - one is linear but coiled = amylose - the other is the branched = amylopectin

Question 36

which structure in starch can be exploited to test

Answer 36

amylose component in starch can be exploited to test for the presence of starch in a solution

Question 37

what happens during a iodine starch test

Answer 37

a solution of iodine/potassium iodine is added to a solution suspected of to contain starch

Question 38

what will happen if starch is present when iodine starch test is added to solution

Answer 38

when this solution is added to any amylose-containing solution the iodine will slip into the amylose coil, resulting in the formation of a dark blue-black color

Question 39

what will happen if no starch is present when iodine starch test is added to solution

Answer 39

the amylose-iodine complex will not be able to form and the iodine will stay its original brown-orange state

Question 40

when is starch not present in solution

Answer 40

when starch has been digested into smaller carbohydrate units