Chp 25 Practice
The sum of all of the biochemical processes going on within the human body at any given time is called
B. metabolism
Reactions within ________ provide most of the energy needed by a typical cell.
A. the mitochondria
The first steps of catabolism generally take place in the
D. cytosol
What is the role of NADH in metabolism?
B. transport hydrogen atoms to coenzymes
When NAD+ is ________ it becomes NADH. When NADH is ________ it becomes NAD+.
A. reduced; oxidized
Which of the following processes represent(s) catabolism?
D. All of these are catabolic processes.
Which of these is NOT part of anabolism?
B. muscle contraction
About 40 percent of the energy content of nutrients is captured as ATP. The remainder is lost as __________.
C. heat
Growth and repair involve primarily what type of reactions?
B. anabolic
Which of the following occurs when water is released (lost) during a reaction?
C. dehydration synthesis
The energy produced from aerobic metabolism comes from what two sources? (Figure 25-5)
E. citric acid cycle and the electron transport chain
The chemical equation that correctly summarizes the overall reaction in oxidative phosphorylation is
A. 2 H2 + O2 → 2 H2O.
The function of the citric acid cycle is to
C. remove hydrogen atoms from organic molecules and transfer them to coenzymes.
In the ETS, ________ accepts electrons from one molecule and transfers them to another.
E. a coenzyme
In oxidative phosphorylation, energy for the synthesis of ATP is directly obtained from the
D. movement of hydrogen ions through channels in the inner mitochondrial membrane.
Although other nutrients can feed into the citric acid cycle, ________ yields energy the quickest.
B. glucose
The strategy of eating starchy foods for several days before an athletic event is known as
A. carbohydrate loading
In glycolysis, each molecule of glucose that is catabolized gives a net yield of how many molecules of ATP?
D. 2
The citric acid cycle occurs in the
C. mitochondrial matrix
How many net ATP molecules are produced by the complete metabolism (all pathways) of one glucose molecule?
A. 30-32 ATP
The carbon dioxide released by the lungs into the atmosphere was very likely produced within __________.
C. the citric acid cycle
Glycolysis yields two molecules of pyruvate. Which of the following statements best describes what next happens to pyruvate?
A. in the presence of oxygen, pyruvate enters a mitochondrion.
Why is it necessary to phosphorylate a glucose molecule, creating glucose-6-phosphate?
D. to trap the glucose molecule within the cell
The energy stored in ATP comes from which of the following?
D. food molecules
How is ATP used in our bodies?
D. The energy released from ATP is converted into kinetic energy to do work
Examine this reaction:
starch⟶(amylase) disaccharides⟶(disaccharidase) monosaccharides
If there is the normal amount of amylase present but less disaccharidase than usual, which of the following would most likely happen?
A. the normal amount of disaccharide would be produced, but fewer monosaccharides would be produced.
Examine the reaction below, and then answer the question.
A+B⟶(Enzyme1) C+D⟶(Enzyme2) E+F⟶ (Enzyme3) G+H
Absence of which enzyme would cause the greatest reduction in the production of G and H?
D. Absence of any of the enzymes would have the same effect—decrease or block the production of G and H.
Which of the following is not a product of cellular respiration?
D. oxygen (O2)
(used during cellular respiration to maximize ATP production.
Which of the following contains the most energy that can be used to make ATP?
D. 1 gram of fat
Where does beta-oxidation take place? (Figure 25-7)
A. in the mitochondria
Lipogenesis generally begins with
C. acetyl-CoA
Which of these is NOT required for glycolysis?
B. pyruvic acid
Through the process of __________, each glucose yields two pyruvate ions.
C. glycolysis
Synthesis of fatty acids starts with __________.
B. acetyl-CoA
Select the correct sequence of steps as energy is extracted from glucose during cellular respiration.
C. glycolysis → acetyl CoA → citric acid cycle → electron transport chain
Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.
What is the correct general equation for cellular respiration?
C. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy
Cellular respiration extracts energy from glucose (C6H12O6) to produce smaller energy packets (ATP).
Which of the following processes takes place in the cytosol of a eukaryotic cell?
electron transport chain
ATP production by ATP synthase
glycolysis
citric acid cycle
acetyl CoA formation
C. glycolysis
Glycolysis, the breakdown of glucose into two molecules of pyruvic acid, takes place in the cytosol, outside the mitochondria.
In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?
A. mitochondrion
All of the steps of cellular respiration except glycolysis take place in the mitochondrion.
Which statement describes glycolysis?
C, This process splits glucose in half and produces 2 ATPs for each glucose.
In glycolysis, glucose is split into two molecules of pyruvic acid. The released energy is stored in ATP and the electron carrier NADH.
Which statement describes the citric acid cycle?
E. This process produces some ATP and carbon dioxide in the mitochondrion.
The citric acid cycle breaks down carbon molecules, releasing carbon dioxide and forming some ATP.
Which statement describes the electron transport chain?
C. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration.
In the electron transport chain, electrons move from one electron carrier to another, eventually reaching oxygen. The released energy is used to make ATPs.
A balanced diet is important to provide the body with all the necessary nutrients to ensure physiological functioning. What is the name of the process where new organic molecules are synthesized?
B. anabolism
In which area do you see most of the cell’s ATP generated by aerobic respiration?
B. mitochondria
More than 90 percent of the ATP generated during aerobic respiration is made in the mitochondria.
Skeletal muscle does each of these EXCEPT __________.
A. pump blood