chapter 9

In the absence of oxygen, what is the net gain of ATP for each glucose molecule that enters glycolysis?

2 ATP

Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?

Anion and cation

Which step of the cellular respiration pathway can take place in the absence of oxygen?

glycolysis

In the combined processes of glycolysis and cellular respiration, what is consumed and what is produced?

Glucose is consumed, and carbon dioxide is produced.

In fermentation _____ is reduced and _____ is oxidized.

pyruvate ... NADH

Which statement about the citric acid cycle is correct? 1. The citric acid cycle oxidizes glucose to carbon dioxide. 2 The citric acid cycle produces most of the ATP that is subsequently used by the electron transport chain. 3 The citric acid cycle depends on the availability of NAD+, which is a product of glycolysis. 4 The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle. 5 The oxidation of compounds by the citric acid cycle requires molecular oxygen.

4

For each glucose that enters glycolysis, _____ NADH + H+ are produced by the citric acid cycle.

6

In glycolysis, what starts the process of glucose oxidation?

ATP

Which stage of glucose metabolism produces the most ATP?

Electron transport and chemiosmosis

In glycolysis, ATP molecules are produced by _____.

substrate-level phosphorylation

In the citric acid cycle, ATP molecules are produced by _____.

substrate-level phosphorylation

True or false? The potential energy in an ATP molecule is derived mainly from its three phosphate groups.

true

True or false? The reactions that generate the largest amounts of ATP during cellular respiration take place in the mitochondria.

true

Which of these enters the citric acid cycle?

acetyl CoA

Which of these is NOT a product of the citric acid cycle?

acetyl CoA

Which of these is NOT a product of glycolysis?

FADH2

For each glucose that enters glycolysis, _____ acetyl CoA enter the citric acid cycle.

2

How many NADH are produced by glycolysis?

2

In glycolysis there is a net gain of _____ ATP.

2

Which of the following statements is true of the bonds in a water molecule? 1. Oxygen acts as the electron acceptor and is oxidized. 2. Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero. 3.There is equal sharing of the electrons between the oxygen atom and the two hydrogen atoms, and the net charge is zero. 4. The electron in each hydrogen atom is completely transferred to the oxygen atom, and each hydrogen atom has a net charge of +1.

2

Which of the following statements about the chemiosmotic synthesis of ATP is correct? 1 The energy for production of ATP from ADP comes directly from a gradient of electrons across the inner mitochondrial membrane. 2 Oxygen participates directly in the reaction that makes ATP from ADP and P. 3 The chemiosmotic synthesis of ATP requires that the electron transport in the inner mitochondrial membrane be coupled to proton transport across the same membrane. 4 The chemiosmotic synthesis of ATP occurs only in eukaryotic cells, because it occurs in mitochondria. 5 Chemiosmotic ATP synthesis requires oxygen.

3

Which of the following statements about the electron transport chain is true? 1 Water is the last electron acceptor. 2 The electron transport chain is the first step in cellular respiration. 3 NADH and FADH2 donate their electrons to the chain. 4 Electrons gain energy as they move down the chain.

3

Which of the following statements is not true of most cellular redox reactions? 1. The reactant that is oxidized loses electrons. 2. Changes in potential energy can be released as heat. 3. A hydrogen atom is transferred to the atom that loses an electron. 4. The electron acceptor is reduced.

3

Which of the following best describes the main purpose of the combined processes of glycolysis and cellular respiration? 1 breaking down ATP, so that ADP and P can be reused 2. producing complex molecules from chemical building blocks 3 the breakdown of glucose to carbon dioxide and water 4 transforming the energy in glucose and related molecules in a chemical form that cells can use for work 5 catabolism of sugars and related compounds

4

Which one of the following statements about the redox reactions of the electron transport chain is correct? 1 NADH gains electrons in the initial reaction of the electron transport chain. 2 The electron transport chain takes electrons from water and gives them to oxygen. 3 The oxidation of NADH is directly coupled to the reduction of oxygen to water. 4 The redox reactions of the electron transport chain are directly coupled to the movement of protons across a membrane. 5 The redox reactions of the electron transport chain are directly coupled with the synthesis of ATP.

4

Which term describes the degree to which an element attracts electrons?

Electronegativity

Which of the following describes the process of glycolysis?

It represents the first stage in the chemical oxidation of glucose by a cell.

During electron transport, energy from _____ is used to pump hydrogen ions into the _____.

NADH and FADH2 ... intermembrane space

In most cells, not all of the carbon compounds that participate in glycolysis and the citric acid cycle are converted to carbon dioxide by cellular respiration. What happens to the carbon in these compounds that does not end up as CO2?

The carbon compounds are removed from these processes to serve as building blocks for other complex molecules

Into which molecule are all the carbon atoms in glucose ultimately incorporated during cellular respiration?

carbon dioxide

Which process is not part of the cellular respiration pathway that produces large amounts of ATP in a cell?

fermentation

Which molecule is metabolized in a cell to produce energy for performing work?

glucose

Gaseous hydrogen burns in the presence of oxygen to form water: 2H2 + O2 → 2H2 O + energy Which molecule is oxidized and what kind of bond is formed?

hydrogen, polar

What kind of bond is formed when lithium and fluorine combine to form lithium fluoride?

ionic

A glucose molecule is completely broken down to carbon dioxide and water in glycolysis and the citric acid cycle, but together these two processes yield only a few molecules of ATP. What happened to most of the energy that the cell obtains from the oxidation of glucose?

it is stored in NADH and FADH2

The proximate (immediate) source of energy for oxidative phosphorylation is _____.

kinetic energy that is released as hydrogen ions diffuse down their concentration gradient

In muscle cells, fermentation produces _____.

lactate and NAD+

In cellular respiration, most ATP molecules are produced by _____.

oxidative phosphorylation

The final electron acceptor of cellular respiration is _____.

oxygen

The electrons stripped from glucose in cellular respiration end up in which compound?

water