clicker questions exam iii

Question 1

What is the difference between myoglobin and hemoglobin?

Answer 1

Myoglobin stores oxygen and hemoglobin transports it

Question 2

The heme group, depending on the amino acid surrounding it, can bind:

Answer 2

Oxygen, co2, carbon monoxide

Question 3

What is the p50 value of myoglobin

Answer 3

2.8 torr

Question 4

What does the slope of the hill plot represent

Answer 4

cooperativity

Question 5

What is the function of the protein surrounding the heme?

Answer 5

Modulates oxygen binding

Question 6

Hemoglobin molecule contains how many Hemes?

Answer 6

4

Question 7

What is the difference between the red and blue molecule shown?

Answer 7

Red- relaxed. r state, OXY
blue: constricted. t state, DEOXY

Question 8

What is the structural reason for the bohr effect?

Answer 8

salt bridge which is lost in r state

Hydrogen binding at n term

Question 9

Remembering the oxygen binding curves, a shift to the left represents?

Answer 9

Tighter binding of oxygen

Question 10

How does BPG help in adapting hemoglobin to higher altitudes

Answer 10

Shifts the oxygen binding curve to the right

Question 11

What is a structural reason for the BPG effect

Answer 11

binds to Beta hemoglobin

Question 12

What effect does Boston mutation have on hemoglobin

Answer 12

Promotes methemoglobin formation

Question 13

What is protein cooperativity?

Answer 13

How one binds compared to the next one binding.

Question 14

How can cooperativity be measured?

Answer 14

Hill Equation

Question 15

What happens to Ligand binding when there is a positive cooperativity

Answer 15

binding increases

Question 16

What is the role of CA +2 in actin filament binding

Answer 16

binds to troponin, rotates, the actin so myosin head can bind to it

Question 17

What causes the myosin power stroke?

Answer 17

Removing ADP

Question 18

What is a similarity of myosin and kinesin movement

Answer 18

They both use ATP
They both move around

Question 19

What is a difference between kinesin and myosin

Answer 19

Myosin comes in groups and is also actin. kinesin only has two heads that rotates and is microfilaments.

Question 20

What is the role of an enzyme?

Answer 20

Speed up reaction

Question 21

Specificity of an enzyme for a substrate is defined by

Answer 21

Active sites shape (amino acids), and complementary.

Question 22

Define what a cofactor is

Answer 22

Another molecule that binds the protein and helps the reaction occur

Question 23

In what way can enzymes be regulated?

Answer 23

Feedback inhibition
Allosteric regulation

Question 24

What is DDGcat=/

Answer 24

Difference between activation energy with and without enzyme

Question 25

What do enzymes change in the energy graph?

Answer 25

Activation energy

Question 26

What stays the same in the energy graph?

Answer 26

Delta G, reactant amount

Question 27

What is the main attribute of an acid/base mechanism?

Answer 27

Proton exchange

Question 28

What defines a covalent bonding mechanism

Answer 28

Chemical bond that is heavy

Question 29

Metal ions can act as what during an enzymatic mechanism

Answer 29

Charge stabilization Ionization agent Shielding agent

Question 30

Define proximity effect

Answer 30

Organization of substrates, closer together will react

Question 31

Define a Mechanism transition state

Answer 31

Intermediate??

Question 32

Which catalytic mechanism is defined by proton movement

Answer 32

Acid base catalyst

Question 33

Which of these counts for no more than 5X effect on rate

Answer 33

Proximity effect

Question 34

Which type of catalyst can use iron

Answer 34

Metal ion aided catalyst

Question 35

What type of mechanism does lysozyme use?

Answer 35

Acid base

Question 36

Why does lysozyme use acid base?

Answer 36

Acid base is major, there is a movement of proton

Question 37

What determines the substrate of serine type protease

Answer 37

Specificity pocket

Question 38

What is affinity labeling?

Answer 38

Trojan horse effect, binds pocket and then binds nearby acid amino acid

Question 39

What catalytic mechanism do serine protease use?

Answer 39

Covalent bond catalysis

Question 40

What kind of mechanism could ATP hydrolysis be classified as?

Answer 40

Acid base catalysis

Question 41

What kind of reaction could ATP phosphorylation be classified as

Answer 41

Covalent bond catalysis

Question 42

What is the role of Mg ++ in these reaction

Answer 42

It's stealing the charge, charge shielding

Question 43

Kinetic data combined with ——- data allows the mechanism of a reaction to be determined

Answer 43

Structural

Question 44

What is meant by order of a reaction

Answer 44

Number of molecules that must combine for reaction to occur

Question 45

What is meant by the term half-life

Answer 45

Time it takes for half material to disappear

Question 46

What order of reaction is half-life usually associated with

Answer 46

One

Question 47

What does catalysis do to activation energy?

Answer 47

Lowers

Question 48

The greater the delta G =/ the more —— the transition state is and the—— the reaction

Answer 48

Unstable, slower

Question 49

How many fold is a reaction with DDG=/ cat of 17.13 kj/mol increased

Answer 49

1000

Question 50

The following reaction 2A +B -> C represents which order of reaction

Answer 50

2

Question 51

If an isotope has a half-life of 11 years, how many years have passed approximately 3.66% remains

Answer 51

55

Question 52

What is the approximate k of an isotope if the half-life is 11 years?

Answer 52

.063/years

Question 53

The determining step of a reaction with a stable intermediate, is the step with the: a. Highest DeltaG B. Smallest DG C. Highest. DDG D. Smallest DDG

Answer 53

Highest DG

Question 54

What does DDG=/ represent

Answer 54

Change in activation energy

Question 55

What is the main assumption of Michaelis-mentee eq.

Answer 55

Steady state

Question 56

What is the difference between a equilibrium and steady state

Answer 56

Steady only forwards, equilibrium forward and backward.

Question 57

What does Km represent?

Answer 57

Substrate concentration

Question 58

What does Kcat/Km represent in enzymes

Answer 58

Catalytic efficiency

Question 59

Why use lineWeaver- Burke instead of michaelis-menten

Answer 59

More accurate

Question 60

When does enzymatic perfection occur?

Answer 60

When it is diffusion is limited.

Question 61

Define random binding reactions

Answer 61

The order in which the substrate binding is random

Question 62

Which type of competition has no change in Km

Answer 62

Noncompetitive

Question 63

Which competition has the inhibitor binding at the substrate binding site

Answer 63

competitive

Question 64

What is the effect of pH on an enzymes kinetics?

Answer 64

Change in Vmax and KM.