Unit 2

Choose the best description of the process of cellular respiration. a. Carbohydrates are broken down with the consumption of oxygen to produce carbon dioxide, water and energy. b. Carbohydrates are broken down with the consumtion of oxygen and water and the release of carbon dioxide and energy. c. Carbohydrates are broken down with the consumption of carbon dioxide producing oxygen and energy. d. Carbohydrates are broken down to form energy in the form of NADH + H and ATP.

a

During a reduction reaction: a. electrons are passed from the molecule which is oxidized to the molecule which is reduced. b. electrons are passed from the molecule that is reduced to the molecule that is oxidized. c. something is not always oxidized. d. something is not always reduced.

a

Glycolysis is an _____________ process. a. anaerobic b. anabolic c. aerobic d. energy-losing

a

In redox reactions: a. A molecule that reduces another is itself oxidized as it loses electrons. b. A molecule that reduces another is itself reduced as it loses electrons. c. A molecule that oxidizes another is itself oxidized as it accepts electrons. d. A molecule that reduces another is itself oxidized as it accepts electrons.

a

In the energy investment phase of glycolysis: a. two molecules of ATP are invested making glucose and its derivatives more reactive. b. glucose and fructose 6-phosphate are phosphorylated through dehydration synthesis reactions. c. two molecules of ATP are phosphorylated making glucose derivatives more reactive. d. two molecules of ATP are used making glucose derivatives less reactive.

a

The coenzyme NAD+, is an example of ____________. Select one: a. a cofactor b. an enzyme c. an apoenzyme d. a catalyst

a

The conversion of NAD+ to NADH is a/an ___________ and it involves ________________. a. reduction; enzymes called dehydrogenases b. reduction; the breakdown of ATP c. oxidation; enzymes called dehydrogenases d. oxidation; the breakdown of ATP

a

_____________ is/are required to begin a reaction. a. Activation energy b. Products c. Sulfuric acid d. Glucose

a

A coupled reaction takes place when: a. the energy used by one reaction is used to fuel another. b. the energy released from one reaction is used to fuel another. c. ATP is phosphorylated to fuel a reaction. d. highly stable phosphorylated intermediates are formed from the hydrolysis of ATP.

b

ATP releases energy by: a. activating its electrons to form ions b. splitting into a phosphate ion and ADP c. combining with other ATP molecules d. passing electrons to NADH

b

During glycolysis a. glucose is broken down and reduced to form two pyruvate molecules, a net of four ATP, and one NADH. b. glucose is broken down and oxidized to form two pyruvate molecules, a net of two ATP, and two NADH. c. glucose is broken down and reduced to form two pyruvate molecules, a net of two ATP and two NADH. d. glucose is broken down and oxidized to form two pyruvate molecules, a net of two ATP and one NADH.

b

Glycolysis accounts for all of the following except: a. production of H2O b. production of pyruvic acid c. production of ATP d. production of NADH

b

In the equation: B + NAD+ → C + NADH + H + the molecule which is reduced is: a. oxygen b. NAD+ c. NADH d. B

b

NAD+ is a modified _____________. a. Glycoprotein b. Nucleotide c. Monosaccharide d. Phosphotidyl inositol molecule

b

Red blood cells of mammals do not have mitochondria. Since red blood cells lack mitochondria, what process provides their energy? a. aerobic respiration b. glycolysis c. alchohol fermentation d. the Krebs cycle

b

Since NAD+ is an ____________ it is able to get_________. a. oxidizing agent; oxidized b. oxidizing agent; reduced c. reducing agent; reduced d. reducing agent; oxidized

b

The third phosphate bond is called a high energy bond because: a. a great deal of energy is required to hydrolyze the bond. b. energy is released when the bond is broken. c. the hydrolysis of the bond is an endergonic reaction. d. the phosphate bond is a particularly strong bond compared to most other covalent bonds in the cell.

b

A component of NAD+ is obtained in the diet from: a. riboflavin b. carotin c. niacin d. nicotine

c

A process during which a substance gains electrons is referred to as: a. Hydrogenation. b. Phosphorylation. c. Reduction. d. Oxidation.

c

NAD+ is: a. formed only under aerobic conditions. b. a reducing agent. c. an oxidizing agent. d. able to serve as a structural molecule in cells.

c

The breakdown of sugar is a(n) _________________ reaction. a. endergonic b. equilibruim c. exergonic d. Both B and C

c

The pathway in which glucose is broken down to form pyruvate is called: a. aerobic respiration. b. the Krebs cycle. c. glycolysis. d. alchohol fermentation.

c

The role of hexokinase in the first part of glycolysis is: a. The phosphorylation of ADP b. The isomerization of glucose to fructose c. The phosphorylation of glucose d. The breaking of the six-carbon sugar into two 3-carbon compounds

c

Which molecule in the reaction pathway provided is the phosphorylated intermediate? X-OH + ATP → X-O-P + ADP A-H + X-O-P → A-X + Pi a. X-OH b. ADP c. X-O-P d. A-X

c

Which of the following does not form during glycolysis? a. Pyruvate b. NADH c. ATP d. FADH2

d

______________ is/are stored in the bonds of a sugar molecule. a. Sweetness b. Sulfuric acid c. Fire d. Energy

d

ATP acts as a carrier of chemical energy. True False

true

ATP is composed of the sugar ribose that has an adenine base and three phosphate groups. True False

true

Pyruvate kinase: a. transfers a phosphate group from PEP to ATP. b. transfers a phosphate group from ATP to form pyruvate. c. catalyzes the formation of pyruvate from 2-phosphoglycerate. d. catalyzes the formation of PEP from pyruvate.

a

Sulfuric acid + sugar + KClO3 ⇒ a. A rapid release of energy in the form of combustion. b. Nothing. c. A regulated release of energy. d. The oxidation of sulfuric acid.

a

The _____ is the electron donor in a reaction: a. molecule which is oxidized b. molecule which is reduced c. product d. enzyme

a

The ultimate goal of cellular respiration is to: a. make energy. b. transfer energy. c. use energy. d. none of the above.

b

When a molecule is reduced, it: a. loses electrons. b. gains electrons. c. gains bonds to oxygen. d. Both A and C.

b

Which of the following molecules are not formed during glycolysis? a.ATP b.FADH2 c.NADH d.Pyruvate

b

Which pathway is common to both fermentation and cellular respiration? a. the electron transport chain b. glycolysis c. the Krebs cycle d. oxidative phosphorylation

b

Which statement regarding the isomerase enzyme in the first half of glycolysis is true? a. Isomerase catalyzes a one-way reaction. b. Isomerase interconverts glyceraldehyde-3-phosphate to dihydroxyacetone phosphate, and vice versa. c. Isomerase converts glucose-6-phosphate to fructose-6-phosphate. d. Isomerase is not an enzyme that functions in the first half of glycolysis.

b

Glycolysis begins in the __________ and ends in the _____________. a. cytoplasm; matrix of the mitochondria b. cytoplasm; innermembrane space of the mitochondria c. cytoplasm; cytoplasm d. cytoplasm; ribosome

c

Glycolysis is an ________ process in which glucose undergoes _________. Select one: a. Aerobic; oxidation b. Aerobic; reduction c. Anaerobic; oxidation d. Anaerobic; reduction

c

Glycolysis occurs in a. animal cells. b. plant cells. c. animal and plant cells. d. animal cells and nonphotosynthetic plant cells.

c

Which of the following reactions could be coupled to an endergonic reaction with a delta G of +2.45 kJ / mole? a. a reaction with a delta G of +6.5 kJ / mole. b. a reaction with a delta G of +2.46 kJ / mole. c. a reaction with a delta G of −5.34 kJ / mole. d. a reaction with a delta G of −1.34 kJ / mole.

c

With respect to the nitrogen atom: a. A is deionization; B is ionization. b. A is oxidation; B is reduction. c. A is reduction; B is oxidation. d. A is dehydrogenation; B is hydrogenation.

c

which statement about the ATP is not true? a. Water is used to break high energy bonds in ATP. b. The formation of ATP from ADP + Pi is an endergonic reaction. c. Part of the ATP molecule is a trisaccharide. d. ATP is the energy currency of all cells.

c

ATP is used by the cell to: a. synthesize biological molecules b. actively transport substances across the membrane c. generate force d. all of the above

d

Adenosine triphosphate __________. a. is a complex nonpolar molecule. b. would not normally be found in a plant cell. c. is formed from the hydrolysis of ADP + Pi. d. has unstable bonds that are weaker than most covalent bonds in organic molecules.

d

An important goal of the energy investment phase of glycolysis is the: a. reduction of coenzymes. b. transport of hydrogen molecules into the mitochondria. c. formation of two pyruvate molecules. d. phosphorylation of a 6-carbon molecule.

d

During two steps in glycolysis, ATP is hydrolyzed in order to form phosphorylated intermediates. Which two enzymes mediate these respective reactions? a. Phosphoglucoisomerase; Aldolase b. Isomerase; Phosphofructokinase c. Hexokinase; Phosphoglucoisomerase d. Hexokinase; Phosphofructokinase

d

In order to prevent combustion inside our bodies when we drink a soda: a. we have developed fireproof digestive tracts. b. sugar is not oxidized in humans. c. we have phagocytotic cells that attack the sugar and safely remove it from our bodies. d. we have evolved mechanisms to regulate the release of energy from sugar.

d

One round of glycolysis: a. involves the reduction of an NAD+ molecule to form a molecule of NADH + H+. b. takes place in the mitochondria. c. uses four ATP. d. involves the use of kinase enzymes to synthesize ATP.

d

Oxidation and reduction: a. are both endergonic reactions. b. involve the gain or loss of electronegativity. c. only take place in anaerobic conditions. d. always take place together.

d

Phosphate group transfers from ATP to other molecules are __________ mechanisms for delivering energy. a. rapid b. renewable c. almost universal d. All of the above

d

Which of the following statements regarding ATP is true? a. The hydrolysis of ATP is endergonic and fuels catabolic reactions. b. ATP is not typically found in plant cells. c. ATP is a large complex molecule that is crucial to life. d. ATP is an energy-carrying molecule.

d

ATP acts as a phosphorylated intermediate used to fuel exergonic reactions. True False

false

True or false? The molecules that result from the first half of glycolysis have a more negative free energy than glucose.

true