BIOL 1030 Chapter 6

Why is the citric acid cycle called a cycle?

Acetyl CoA binds to oxaloacetate and this compound is restored at the end of the cycle.

The energy released from the redox reactions in the electron transport chain is used by the cell to make _______ .

ATP

During chemiosmosis,

ATP is synthesized when H+ ions move through a channel in ATP synthase.

The function of cellular respiration is to _____.

extract usable energy from glucose

As a result of glycolysis, there is a net gain of ________ ATP(s).

2

The burning of food via cellular respiration must provide the average adult approximately _________ kilocalories per day.

2,200

Which of the following best describes the electron transport chain?

Electrons pass from one carrier to another, releasing a little energy at each step.

Given the relatively modest number of calories burned by anything but the most vigorous activities, why can people consume over 2,000 kilocalories a day, yet maintain a healthy body weight?

Most of the energy consumed in food is spent maintaining the body's functions, so only a fraction of food energy needs to be burned in exercise.

In cellular respiration, organic molecules become oxidized as __________ picks up electrons and H+ and becomes reduced to NADH.

NAD+

At the end of the citric acid cycle, most of the energy remaining from the original glucose is stored in

NADH

Which of the following statements regarding the movement of electrons during cellular respiration is true?

O2 is reduced when it accepts electrons and forms water.

Consider the figure below. __________ is to a mitochondrion as __________ is to a chloroplast.

O2.....CO2

Which step of the citric acid cycle requires both NAD+ and ADP as reactants?

Which step of the citric acid cycle requires both NAD+ and ADP as reactants?

Which energy-rich molecule produced by cellular respiration directly powers cell work?

atp

A culture of bacteria is fed glucose containing radioactive carbon and is then examined. During the citric acid cycle, radioactive carbon would first appear in

citrate.

Which of the following is a result of glycolysis?

conversion of glucose to two three-carbon compounds

During cellular respiration, NADH

delivers its electron load to the first electron carrier molecule.

The transfer of __________ from one molecule to another is an oxidation-reduction reaction, or redox reaction.

electrons

During redox reactions,

electrons are lost from one substance and added to another substance.

Which of the following are products of cellular respiration?

energy to make ATP and carbon dioxide and water

Pyruvate

forms at the end of glycolysis.

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________.

four; 3 NADH and 1 FADH2

Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?

glucose

In the equation shown below, during cellular respiration __________ is oxidized and __________ is reduced.

glucose ... oxygen

Where does glycolysis occur in a eukaryotic cell?

in the cytoplasmic fluid

Respiration ________, and cellular respiration ________.

is gas exchange; produces ATP

In cellular respiration, glucose _____ electrons, whereas _____ electrons.

loses ... oxygen gains

A molecule that functions as the electron donor in a redox reaction __________.

loses electrons and becomes oxidized

Oxidation is the ________, and reduction is the ________.

loss of electrons; gain of electrons`

A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes?

mitochondrial matrix

In cellular respiration, glucose becomes _____________ to carbon dioxide (CO2) as it loses electrons (in hydrogen atoms).

oxidized

NADH delivers electrons to an electron transport chain, which passes the electrons through carrier molecules in a series of redox reactions to the final electron acceptor, _________.

oxygen

In cellular respiration, oxygen becomes ___________ to water (H2O) as it gains electrons (in hydrogen atoms) that came from glucose.

reduced

Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by providing __________

the energy necessary to power the rearrangement of chemical bonds in H2O and CO2

Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____.

these two stages supply the electrons needed for the electron transport chain