Chapter 9 Bio Exam

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

2. Each glucose produces two pyruvates, each of which is converted into acetyl CoA.

In glycolysis there is a net gain of _____ ATP.

2. It takes two ATP to make four.

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

6. 3 NADH + H+ are produced per each acetyl CoA that enters the citric acid cycle.

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

acetyl CoA. Acetyl CoA enters the citric acid cycle.

Which of these enters the citric acid cycle?

acetyl CoA. Acetyl CoA is a reactant in the citric acid cycle.

Which of the following statements is not true of most cellular redox reactions?

A hydrogen atom is transferred to the atom that loses an electron. A hydrogen atom (proton, or H+) is often transferred to the atom that gains an electron.

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

substrate-level phosphorylation. A phosphate group is transferred from GTP to ADP.

In glycolysis, ATP molecules are produced by _____.

substrate-level phosphorylation. A phosphate group is transferred from glyceraldehyde phosphate to ADP.

Which of the following best describes the main purpose of the combined processes of glycolysis and cellular respiration?

transforming the energy in glucose and related molecules in a chemical form that cells can use for work. The energy made available during cellular respiration is coupled to a production of ATP, the basic energy currency that cells use for work.

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 of these is NOT a product of glycolysis?

FADH2. This is a product of the citrus acid cycle.

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

Glucose is consumed, and carbon dioxide is produced. The carbon in glucose is oxidized to carbon dioxide during cellular respiration

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. Hydrogen loses electrons to oxygen, which is more electronegative and thus pulls the electrons closer to itself in the water molecule.

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 electrons obtained from the oxidation of glucose are temporarily stored in NADH and FADH2. The energy derived from the oxidation of NADH and FADH2 is used to drive the electron transport chain and chemiosmotic synthesis of ATP.

The final electron acceptor of cellular respiration is _____.

Oxygen is combined with electrons and hydrogen to form water.

Which of the following statements about the chemiosmotic synthesis of ATP is correct?

The chemiosmotic synthesis of ATP requires that the electron transport in the inner mitochondrial membrane be coupled to proton transport across the same membrane. Chemiosmosis uses the energy of a proton gradient to make ATP; the proton gradient is formed by coupling the energy produced by electron transport with movement of protons across the membrane.

How many NADH are produced by glycolysis?

Two NADH molecules are produced by glycolysis.

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

Water. At the end of the electron transport chain, the electrons and hydrogen atoms are added to oxygen, forming water.

Which of the following statements is true of the bonds in a water molecule?

Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero. The oxygen and hydrogen atoms in water have partial charges, but the molecule has a net charge of zero.

In glycolysis, what starts the process of glucose oxidation?

Some ATP energy is used to start the process of glucose oxidation.

Which of the following describes the process of glycolysis?

It represents the first stage in the chemical oxidation of glucose by a cell. Catabolism of glucose begins with glycolysis.

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

NADH and FADH2 ... intermembrane space. The energy released as electrons, which have been donated by NADH and FADH2, is passed along the electron transport chain and used to pump hydrogen ions into the 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. Glycolysis and the citric acid cycle provide many compounds that are the starting point for the synthesis of amino acids and lipids.

Which statement about the citric acid cycle is correct?

The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle.

In fermentation _____ is reduced and _____ is oxidized.

The pyruvate from glycolysis is reduced to either lactate or ethanol, and NADH is oxidized to NAD+.

Which one of the following statements about the redox reactions of the electron transport chain is correct?

The redox reactions of the electron transport chain are directly coupled to the movement of protons across a membrane. The reduction and oxidation of electron carriers in the electron transport chain provide the energy to move protons across a membrane against the chemical gradient of protons.

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

kinetic energy that is released as hydrogen ions diffuse down their concentration gradient. Concentration gradients are a form of potential energy.

In muscle cells, fermentation produces _____.

lactate and NAD+. These are the products of fermentation as it occurs in muscle cells.

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

oxidative phosphorylation. This process utilizes energy released by electron transport.

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

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