Why is ATP an important molecule in metabolism?

1
Why is ATP an important molecule in metabolism?

• A) Its synthesis is exergonic
• B) It is extremely stable.
• C) Its hydrolysis is endergonic.
• D) It is readily obtained from an organism's
  environment.
• E) Its phosphate bonds are easily formed and
  broken.

2
Which of the following is true for all exergonic
reactions?

• The products have more total energy than the
  reactants.
• The reaction proceeds with a net release of free
  energy.
• Some reactants will be converted to products.
• A net input of energy from the surroundings is
  required for the reactions to proceed.
• The reactions are nonspontaneous.

3
Which of the following statements correctly
describe(s) catabolic pathways?

• They do not depend on enzymes.
• They consume energy to build up polymers from
  monomers.
• They release energy as they degrade polymers to
  monomers.
• They lead to the synthesis of catabolic
  compounds.
• both A and B

4
The Second Law of Thermodynamics

• States that all matter goes spontaneously from
  stable to unstable states
• Says that energy cant be created or destroyed
• States that all matter spontaneously moves to a
  state of higher entropy
• All of the above

5
Coupled metabolic reactions

• Usually involve the hydrolysis of ATP
• Allow anabolic reactions to occur at the expense
  of catabolic reactions
• Allow endergonic reactions to occur at the
  expense of exergonic reactions
• All of the above

6
Which of the following statements correctly
describe(s) some aspect of energy in living
organisms?

• Living organisms can convert energy among several
  different forms.
• Living organisms can use energy to do work.
• Organisms expend energy in order to decrease
  their entropy
• A and B only
• A, B, and C

7
Autotrophic organisms

• Include animals
• Dont carry out cellular respiration
• Produce their own chemical energy from sunlight
  and inorganic molecules
• Violate the first law of thermodynamics

8
An enzyme catalyzes a reaction by

• changing the equilibrium of a spontaneous
  reaction.
• increasing the amount of free energy of a
  reaction.
• lowering the energy of activation of a reaction.
  
• supplying the energy to speed up a reaction.
• lowering the ?G of a reaction.  

9
Increasing the substrate concentration in an
enzymatic reaction could overcome which of the
following

• denaturation of the enzyme
• insufficient cofactors
• saturation of the enzyme activity
• noncompetitive inhibition
• competitive inhibition  

10
Reactants capable of interacting to form products
in a chemical reaction must first overcome a
thermodynamic barrier known as the reaction's

• entropy.
• activation energy.
• endothermic level.
• heat content.
• free-energy content.

11
What is a nonprotein "helper" of an enzyme
molecule called?

• accessory enzyme
• allosteric group
• coenzyme
• functional group
• enzyme activator

12
Increasing the substrate concentration in an
enzymatic reaction could overcome which of the
following

• denaturation of the enzyme
• insufficient cofactors
• saturation of the enzyme activity
• noncompetitive inhibition
• competitive inhibition  

13
The mechanism in which the end product of a
metabolic pathway inhibits an earlier step in the
pathway is known as

• metabolic inhibition.
• feedback inhibition.
• denaturation.
• cooperative inhibition.
• irreversible inhibition.

14
Conformational changes in enzyme molecules are
important in this process

• enzymes raising the energy of activation of a
  reaction
• noncompetitive inhibition
• enzymes converting a nonspontaneous reaction
  into a spontaneous reaction
• d) competitive inhibition.

15
During a laboratory experiment, you discover
that an enzyme-catalyzed reaction has a Delta G
-20 kcal/mole. You double the amount of enzyme in
the reaction and the Delta G now equals

• A) -10 kcal/mole.
• B) -20 kcal/mole.
• C) 40 kcal/mole.
• D) -40 kcal/mole.
• E) It is not possible to calculate the answer
  with the data given.

16
Which of the following processes does not produce
NADH H?

• glycolysis
• conversion of pyruvate to acetyl-CO-A
• TCA cycle
• conversion of pyruvate to lactic acid.

17
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
CO2 produced?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

18
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
ATP produced by substrate level phosphorylation?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

19
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
NAD reduced?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

20
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
NADH oxidized?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

21
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
oxygen directly involved?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

22
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
ATP used ?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

23
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
FADH2 oxidized?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

24
For the following question 1glycolysis,
2citric acid cycle 3ETS. In which of these is
ATP produced by oxidative phopshorylation?

• 1
• 2
• 3
• 12
• 13
• 23
• 1,2,3

25
How many net ATP per glucose are produced during
glycolysis?

• 0
• 2
• 4
• 34
• 38

26
How many net ATP per glucose are produced during
aerobic cellular respiration?

• 0
• 2
• 4
• 34
• 38

27
Which of the following sets of reactions is
common to both aerobic respiration and
fermentation?

• glycolysis
• TCA cycle
• electron transport system
• a b
• b c.

28
The major (but not sole) energy accomplishment of
the Krebs cycle is

• formation of CO2
• formation of ATP
• formation of NADH and FADH2
• utilization of oxygen
• completion of substrate phosphorylations

29
The immediate energy source that drives ATP
synthesis during oxidative phosphorylation is

• the oxidation of glucose and other organic
  compounds
• the flow of electrons down the electron
  transport chain
• the affinity of oxygen for electrons
• a difference of H concentration on opposite
  sides of the inner mitochondrial membrane
• the transfer of phosphate from Krebs cycle
  intermediates to ADP.

30
Which of the following statements is false?

• oxidative phosphorylation produces 32 of the 36
  ATP produced from every glucose molecule
• every NADH2 produced by the Kreb's cycle adds 6
  H to the hydrogen pool in the intermembrane
  space
• glycolysis produces less net molecules of ATP
  than fermentation
• for every 2 H ions that go through the ATPase
  channel, 1 ATP can be made.

31
Which of the following compounds is a reduced
form of a coenzyme?

• FADH2
• ATP
• ADP
• H2O
• NAD.

32
The Kreb's cycle

• does not occur in the mitochondria
• reoxidizes NADH2 back into NAD
• will operate in the absence of oxygen
• contains a step that is a substrate-level
  phosphorylation.

33
Which of the following coenzymes would have to be
continually present in the cell in order for the
oxidation reactions of glycolysis to occur?

• FADH2
• NADH
• ATP
• NAD
• all of the above. 

34
During photosynthesis in a eukaryotic cell, the
Calvin cycle reactions occur in

• the thylakoid membrane
• the (inner) thylakoid space (lumen)
• the stroma
• the matrix
• the cytosol 

35
In photosynthesis, light energy is used to remove
electrons and protons from water and ultimately
transfer them to

• RUBISCO
• NADP
• oxygen
• ATP  

36
One of the compounds produced by the
light-dependent reactions and required for the
light-independent reactions of photosynthesis is

• ATP
• NADP
• oxygen gas (O2)
• carbon dioxide (CO2). 

37
Light-dependent reactions do all of the following
EXCEPT

• convert sunlight to chemical energy
• synthesize ATP and NADPH
• reduce CO2
• convey excited electrons from chlorophyll to an
  electron acceptor.

38
The two photosystems of photosynthesis are
connected by

• chlorophyll molecules
• an electron transport chain
• NADP molecules
• dark reactions
• antennae pigments
• the stroma

39
Which of the following sequences correctly
represents the flow of electrons during
photosynthesis?

• NADPH O2 CO2
• H2O NADPH Calvin cycle
• NADPH chlorophyll Calvin cycle
• H2O photosystem I photosystem II
• NADPH electron transport chain O2.

40
What is the function of ribulose biphosphate
(RuBP)during photosynthesis?

• It produces the CO2 needed for photosynthesis.
• It combines with CO2 to produce a six-carbon
  compound.
• It combines with ATP to form PGAL.
• It produces the oxygen that is released. 

41
During photosynthesis, oxygen is derived from

• carbon dioxide.
• water.
• cytochrome.
• glucose.
• PGAL.

42
Chlorophyll extracted from a plant cell and
placed in a test tube cannot produce glucose
because

• the necessary thylakoid membranes are lacking
• chlorophyll is not involved in making glucose
• plant cells do not contain chlorophyll, animal
  cells do
• chlorophyll extracted from a plant cell cannot
  absorb light 

43
An electron that has been excited to a higher
orbital by an input of energy will

• be stable
• have a lower free energy in its new location
• eventually return to its ground state
• remain in its new orbital indefinitely.

44
CAM plants keep stomata closed in daytime, thus
reducing loss of water. They can do this because
they

• A) fix CO2 into organic acids during the night.
• B) fix CO2 into sugars in the bundle-sheath
  cells.
• C) fix CO2 into pyruvate in the mesophyll cells.
• D) use the enzyme phosphofructokinase, which
  outcompetes rubisco for CO2.
• E) use photosystems I and II at night.

45
Photorespiration

• oxidizes RUBP
• produces ATP
• is favored by high concentrations of carbon
  dioxide
• occurs most often when the stomates are open.