O Chem Final

Front 1

For which of the following processes will entropy increase?

Back 1

conversion of CO2(s) ("dry ice") to CO2(g)

Front 2

For a particular reaction, ΔH and ΔS are both positive. Under what temperature conditions will the reaction be spontaneous?

Back 2

It will be spontaneous above a certain cutoff temperature but not spontaneous below it

Front 3

If ΔGo is negative for a reaction, then

Back 3

K>0

Front 4

Exergonic reactions:

Back 4

release energy

are spontaneous reactions

have an equilibrium constant greater than 1

can be coupled to endergonic reactions

***All of the Above***

Front 5

Energy-requiring reactions can occur in biological systems because enzymes allow their coupling to other reactions with:

Back 5

products of lower free energy than the reactants

Front 6

The result of a(n) ............. reaction is that energy is released. Energy must be added for a(n) ............. reaction to proceed

Back 6

exergonic, endergonic

Front 7

Describe the typical energetics of enzyme-substrate complex formation.

Back 7

enthalpy and entropy both decrease

Front 8

In the reaction, CO (g) + NO2 (g) < -- > CO2 (g) + NO (g), which of the following changes would result in the formation of more products at equilibrium?

Back 8

adding NO2 (g) to the reaction

Front 9

Equiliblrium is a state of dynamic molecular behavior, meaning that

Back 9

reactants turn into products and products turn into reactants at equal rates

Front 10

The principle of microscopic reversibility states that:

Back 10

A. All reactions have the same rate constants for the forward and backward reactions.

B. The mechanism of the reverse reactions is the exact reversal of the mechanism of the forward reaction.

D. The absolute value of ΔG of the forward reaction is the same as the value for the reverse reaction.

Front 11

Carbonyl addition reactions that are reversible tend to have

Back 11

Stable leaving groups

Front 12

Within the HSAB theory, a hard acid:

Back 12

is not very polarizable

Front 13

Rank sulfur's binding preference for making a complex with these metals (strongest attraction to weakest).

Back 13

Hg2+ > Zn2+ > Fe2+ > Mg2+

Front 14

In coordination chemistry, the donor atom of a ligand is

Back 14

the atom in the ligand that shares an electron pair with the metal

Front 15

Which of these are true? (all of them)

Back 15

Diamagnetic metal ions cannot have an odd number of electrons.

Low spin complexes can be paramagnetic.In high spin octahedral complexes,

Δo is less than the electron pairing energy, and is relatively very small.

Low spin complexes contain strong field ligands.

Front 16

In an octahedral ligand field, which d orbitals are raised least in energy?

Back 16

dxy, dxz and dyz

Front 17

Which of the following complexes is diamagnetic?

Back 17

A low spin octahedral Co3+ complex

Front 18

Which of the following is NOT a significant advantage of a MOF as a structure for storing simple molecules?

Back 18

Large holes in the structure.

Front 19

Which functional group is the most electrophilic?

Back 19

acid anhydride

Front 20

Which statement is incorrect about CO ligands?

Back 20

In the IR spectrum of Fe(CO)5, absorptions assigned to the CO stretching modes are at higher wavenumber than that of free CO

Front 21

Enzymes:

Back 21

-are composed primarily of polypeptides, which are polymers of amino acids.

-can bind prosthetic groups such as metal ions that participate in enzyme reactions.

-have defined structures.

-bind their substrates at active sites.

Front 22

One of the most common post-translational modifications is phosphorylation. Which of the following amino acids is most likely to be phosphorylated?

Back 22

Ser

Front 23

An enzyme:

Back 23

stabilizes the transition state more than the enzyme-substrate complex.

Front 24

Metals in enzymes:

Back 24

-stabilize increased electron density

-stabilize negative charges

-increase the acidity of water

-activate carbonyl functional groups

Front 25

Not all of the ten reactions in glycolysis are regulated. What is the relationship between the sign/magnitude of ΔG for a step and whether it is regulated?

Back 25

steps in which ΔG is large and negative tend to be regulated.

Front 26

Which of the following is NOT true of hemoglobin?

Back 26

Binding of oxygen is not accompanied by any change in the protein structure.

Front 27

Acylation of the appropriate amino acid side chains in a protein

Back 27

will take positive sidechains and make them neutral.

Front 28

Prenylation

Back 28

-usually involves Cys side chains

- is important in targeting proteins to cell membranes

-increases the lipophilicity of the protein

Front 29

Which steps in a biological pathway are usually regulated?

Back 29

First step and branch point

Front 30

Which of these enzyme reactions is reversible in glycolysis?

Back 30

3-phosphoglycerate kinase

Front 31

The phosphofructokinase-2 enzyme that transfers a phosphate group to fructose-6-phosphate in glycolysis

Back 31

Produces fructose-1,6-bisphosphate as a product.

Front 32

The ATP/AMP ratio has a major effect upon the rate of ATP production by glycolysis. ATP and AMP bind to allosteric sites on

Back 32

Phosphofructokinase-1

Front 33

Which of the following statements about pyruvate kinase is false?

Back 33

Is also involved in gluconeogenesis

Front 34

An increased concentration of insulin after meals causes an increase in the rate of glycolytic pathway by all of the following mechanisms except:

Back 34

Activation of fructose-2,6-bisphosphatase and inhibition of phosphofructokinase-2

Front 35

Which of the following hormones leads to activation of triglycerol lipase?

Back 35

glucagon

Front 36

Which of the following is not a product of glycolysis?

Back 36

CO2

Front 37

Glycolysis takes place in the .......... and fatty acid synthesis takes place in the ...........

Back 37

cytosol, cytosol

Front 38

In the citric acid cycle, ATP is likely to be a/an ............ for one or more enzymes in the cycle.

Back 38

inhibitor

Front 39

Which of the following is true about insulin?

Back 39

It gives the signal to open the cell so that glucose can enter.

Front 40

***

Back 40

***