bio

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

glucose

Which of the following processes takes place in the cytosol of a eukaryotic cell?

glycolysis

Which stage of cellular respiration appears to have evolved first?

glycolysis Glycolysis can occur in the absence of oxygen and evolved prior to oxygenic photosynthesis.

In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to __________.

pump protons (H+) across the mitochondrial membrane The energy harvested from many redox reactions is used to power proton pumps that span the inner mitochondrial membrane.

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

electron

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

glucose ... oxygen

What molecules belong in space A and B?

glucose and oxygen

What is the correct general equation for cellular respiration?

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy

We inhale O2 and we exhale CO2. Carbon dioxide is produced __________.

in the reaction that creates acetyl CoA (coenzyme A) from pyruvate

In the citric acid cycle (also called the Krebs cycle), ATP molecules are produced by _____

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

Most NADH molecules generated during cellular respiration are produced during __________.

the citric acid cycle

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 The main function of glycolysis and the citric acid cycle is to supply oxidative phosphorylation with electrons carried by NADH and FADH2.

In glycolysis there is a net gain of _____ ATP.

2 It takes 2 ATP to produce 4 ATP.

How many NADH are produced by glycolysis?

2

A gram of fat oxidized by cellular respiration produces approximately __________ as much ATP as a gram of carbohydrate.

2 Fats are excellent fuels because they store so much energy for their mass.

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

ATP

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

ATP

In glycolysis, what starts the process of glucose breakdown?

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

What occurs as electrons pass through the multiple carrier molecules of the electron transport chain?

Energy is released in a stepwise fashion

Which of these is NOT a product of glycolysis?

FADH2 FADH2 is a product of the citric acid cycle.

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

NAD+

What molecule releases the electrons used in the electron transport chain?

NADH

Glycolysis is the multi-step breakdown of _____. Several different _____ play a role in this process.

glucose ... enzymes

What is the purpose of embedding the electron transport chain in the membrane of a cell?

The electron acceptors can transport H+ across the membrane, which is otherwise impermeable to H+.

Which statement describes the electron transport chain?

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.

Which of these is NOT a product of the citric acid cycle (also called the Krebs cycle)?

acetyl CoA

Which of these enters the citric acid cycle (also called the Krebs cycle)?

acetyl CoA Acetyl CoA is a reactant in the citric acid cycle (also called the Krebs cycle).

Select the correct sequence of steps as energy is extracted from glucose during cellular

glycolysis → acetyl CoA → citric acid cycle → electron transport chain

Identify Structure A.

glycoprotein Structure A is composed of both a carbohydrate and a protein.

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because _____.

human cells also perform glycolysis; the drug might also poison them

When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to __________.

kinetic energy and heat

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

Lungs are to breathing as _____ are to cellular respiration.

mitochondria

In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?

mitochondrion

What organelle is indicated by the letter C?

mitochondrion

Some human cells, such as nerve cells, are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then __________.

oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain

In cellular respiration, glucose becomes _________oxidized 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.

oxygen

What is/are the most important output(s) of glycolysis?

two pyruvic acid and two NADH molecules

Aliyah is studying cells as they proceed through redox reactions. If she could measure the number of electrons in the cells' organic fuel and the number of NADH molecules, how would they change as redox reactions proceed? Would she expect the organic fuel to gain or lose electrons? Would she expect there to be more or fewer NADH molecules?

Organic fuel loses electrons; more NADH molecules

Which statement describes the citric acid cycle?

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 glycolysis?

This process splits glucose in half and produces 2 ATPs for each glucose.

Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2?

We would not make enough ATP to meet our energy requirements

What process occurs in structure H?

What process occurs in structure H?

During the first step of a redox reaction, what does the enzyme dehydrogenase strip from organic fuel?

hydrogen atoms

Unlike the Citric Acid cycle and electron transport, glycolysis occurs

in the cytoplasm

Where does glycolysis occur in a eukaryotic cell?

in the cytoplasmic fluid

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

reduced

Glycolysis is the only stage of cellular respiration that __________.

requires ATP to make ATP Glycolysis contains an "investment" phase and a "payoff" phase. Two ATP are required to make four ATP.

what is the function of structure e?

stabilization of the phospholipids Cholesterol helps to stabilize the structure of the plasma membrane.

In glycolysis, ATP molecules are produced by _____.

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

Identify Structure D.

phospholipid bilayer of membrane Phospholipids can be recognized by the presence of a head and two tails.

Cellular respiration requires fuel (glucose) and oxygen gas. The main process that produces these inputs is _____.

photosynthesis

A muscle cell deprived of molecular oxygen will convert glucose to lactic acid to __________.

recycle NADH through fermentation

In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as __________. These other stages occur in the __________.

ATP ... mitochondria

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

carbon dioxide Cellular respiration, or the oxidization of glucose, involves the release of CO2.

What molecules belong in spaces E and F?

carbon dioxide and water

Which part(s) of cellular respiration require(s) oxygen gas?

citric acid cycle and electron transport chain but not glycolysis

Fat is the most efficient molecule for long-term energy storage, even compared to carbohydrates, because _____.

with their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons

Recall from Chapter 4 that phospholipids have two parts: a nonpolar head and two nonpolar tails. In an oil-based, nonpolar environment, phospholipids would arrange themselves so that they __________.

would stay together but in a reverse orientation, with their tails projecting outward