Biol 1306 Cellular Respiration and Fermentation

A molecule becomes more oxidized when it __________

loses an electron

Which substances are involved in oxidative phosphorylation?

ADP, ATP, oxygen

In glycolysis in the absence of oxygen, cells need a way to regenerate which compound?

NAD+

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________

NADH

When protein molecules are used as fuel for cellular respiration, __________ are produced as waste

amino groups

During aerobic respiration, molecular oxygen (O2) is used for which of the following purposes?

at the end of the electron transport chain to accept electrons and form H2O

Where do the reactions of glycolysis occur in a eukaryotic cell?

cytosol

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and after a few minutes radioactive oxygen atoms showed up in __________

carbon dioxide

Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?

citric acid cycle

Which of the following best describes the electron transport chain?

electrons are passed from one carrier to another, releasing a little energy at each step

Which of the following is the source of the energy that produces the chemiosmotic gradient in mitochondria?

electrons moving down the electron transport chain

Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step __________

enables the cell to recycle thereduce NADH to oxidized NAD+

The function of cellular respiration is to ______

extract usable energy from glucose

Which of the following represents the major (but not the only) energy accomplishment of the citric acid cycle?

formation of NADH and FADH2

How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen?

four

In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced

glucose (oxidized) oxygen (reduced)

Of the metabolic pathways listed below, which is the only pathway found in all organisms?

glycolysis

Which process is the one in which glucose is oxidized to generate two molecules of pyruvate, and in which ATP and NADH are produced?

glycosis

During respiration in eukaryotic cells, the electron transport chain is located in or on the __________

inner membrane of the mitochondrion

Each ATP molecule contains about 1% of the amount of chemical energy available from the complete oxidation of a single glucose molecule. Cellular respiration produces about 32 ATP from one glucose molecule. What happens to the rest of the energy in glucose?

it is converted to heat

Sports physiologists at an Olympic training center wanted to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for a buildup of which of the following compounds?

lactate

If muscle cells in the human body consume O2 faster than it can be supplied, which of the following is likely to result?

muscle cells would not be able to produce enough ATP to meet demands, oxidative phosphorylation would stop, and muscle cells would consume glucose at an increased rate

Which of the following is a correct description of the events of cellular respiration and the sequence of events in cellular respiration?

oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation

Most of the ATP produced in cellular respiration comes from which of the following processes?

oxidative phosphorylation

During the reaction C6H12O6 + 6 O2 → 6 CO2 + 6 H2O, which compound is reduced as a result of the reaction?

oxygen

In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?

pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH

Most of the electrons removed from glucose by cellular respiration are used for which of the following processes?

reducing NDA+ ro NADH in glycolysis and the critic acid cyle; producing a proton gradient for ATP synthesis in the mitocondria

Muscle tissues make lactate from pyruvate to do which of the following?

regenerate NAD+

Which of the following statements is the best explanation of what happens to the temperature and carbon dioxide concentration during a one-hour class period in a classroom of 300 students if the heating and air conditioning is turned off and all doors are kept closed?

temperature and the level of carbon dioxide rise as heat and carbon dioxide are by-products of cellular respiration

If a compound that allows protons to freely diffuse across membranes is added to cells that are actively metabolizing glucose via cellular respiration, which of the following processes would stop?

the chemiosmotic synthesis of ATP would stop in the mitochondria, but substrate-level phosphorylation could continue

Which part of the catabolism of glucose by cellular respiration requires molecular oxygen (O2) and produces CO2?

the combination of the citric acid cycle and electron transport

Why is the critic acid cycle called a cycle?

the four-carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step of the cycle

Where do the reactions of the citric acid cycle occur in eukaryotic cells?

the matrix of the mitochondrion

In glycolysis, there is no production of carbon dioxide as a product of the pathway. Which of the following is the best explanation for this?

the products of glycosis contain the same total number of carbon atoms as in the starting material