Biology Chapter 10 Semester Exam Review Questions

Glycolysis yields ____________ molecules of ATP, while the electron transport chain yields ____________molecules of ATP due to the presence of oxygen.

2, 32

Identify the electron carriers of cellular respiration. Discuss the relationship between the electron carriers and the electron transport chain.

NADH and FADH2, the electron carriers pass the electrons from 1 process to the next

Natasha is making a model of cellular respiration. Her model shows the pathway followed when there is enough oxygen available. What does Natasha's model show?

an aerobic pathway consisting of glycolysis, the Krebs cycle, and the electron transport chain

Certain bacteria that produce lactic acid as a waste product during fermentation, an ____________ process, are important to the food industry. This lactic acid is what gives yogurt its ____________ taste. From the graph, based on the pH after 4 hours, the ____________ would taste the most acidic.

anaerobic, sour, the L. bulgaricus and S. thermophiles group

Morgan has diabetes and must carefully monitor his food intake. He is learning the calorie count of the different macromolecules—carbohydrates, proteins, and fats—so that he can make choices to keep his blood sugar in the proper range. He notices that the word calorie is sometimes spelled with a capital C. Which statements accurately describe calories and Calories? Select all of the answers that apply.

-A Calorie is equal to 1000 calories. -A Calorie is equal to a kilocalorie.

Celeste and Raymond are studying the differences between prokaryotes and eukaryotes. They learn that in eukaryotic cells the electron transport chain is in a different location than in prokaryotic cells. Which statements give the correct explanation of this difference?

-In eukaryotes, the electron transport chain is composed of a series of electron carriers located in the inner membrane of the mitochondrion. -In prokaryotes, the electron transport chain is in the cell membrane.

The overall reactions for photosynthesis and cellular respiration are opposite of each other. Select two statements that describe the two processes.

-Photosynthesis uses carbon dioxide from the atmosphere and produces oxygen. -Cellular respiration uses oxygen to release energy from food and produces carbon dioxide as a by-product.

The process of combustion, or burning, is similar to the chemical processes that release energy in cells. Wood burns at a very high temperature, about 600°C. Which two statements explain how the human body is able to obtain energy without becoming too hot?

-The breakdown of glucose occurs in many small steps. -Low-temperature breakdown of glucose is enabled by enzymes that catalyze specific reactions.

Cellular respiration yields about ____ of the energy of glucose in ATP molecules.

39%

What process will occur next to make the dough rise?

Alcoholic fermentation takes place and ethyl alcohol and CO2 gas are formed, creating pockets in the dough.

The molecules in the food we eat contain chemical energy stored in chemical bonds. Which statement BEST explains how this energy is released?

Chemical bonds in food molecules are broken, releasing energy and allowing cells to use the energy to make ATP.

ATP, a higher-energy molecule than ADP, is synthesized from ADP in the electron transport chain. Given that molecules cannot go from a lower energy to a higher energy on their own without an external input of energy, how does the energy for this reaction enter the system?

Energy enters the system when NADH and FADH2 carry their high-energy electrons to the electron transport chain where, through chemiosmosis, their energy is used to transport hydrogen ions across the membrane into the intermembrane space, causing the buildup of a charge difference.

Explain how high-energy electrons are used by the electron transport chain to produce ATP.

Every time 2 high energy electrons pass down the electron transport chain, their energy is used to transport hydrogen ions (h+) across the membrane

Xavier and Jill are practicing the 100-meter sprint. Which statement BEST describes the metabolic pathways their muscles will utilize to produce the quick energy needed for this intense exercise?

Glycolysis begins glucose metabolism, and in the absence of oxygen, lactic acid fermentation takes over.

List the main events of glycolysis. How many ATP molecules are produced and consumed by glycolysis? What effect does the presence of oxygen have on the events that follow glycolysis?

Glycolysis is the breakdown of glucose into two molecules of pyruvic acid, 2 ATP molecules *If oxygen is present, glycolysis leads to the Krebs cycle (citric acid cycle) and the electron transport chain *If oxygen is not present, glycolysis is followed by the rest of fermentation

Air and water pollution from industrial waste is a major global challenge, and is largely driven by societal needs and wants. Biochemists know that plants function as small chemical factories, yet produce no toxic waste. These tiny factories in plants are everywhere, synthesizing carbohydrates from photosynthesis, utilizing cellular respiration for energy production, and producing food for animals all at the same time. How can this knowledge, along with modern technology, best be applied to reduce industrial pollution?

Plants can be genetically modified to synthesize compounds that currently are made in chemical factories that produce hazardous wastes.

Describe the main steps and the results of the Krebs cycle.

Pyruvic acid is broken down into CO2 in a series of energy-extracting reactions. Coenzyme A forms acetyl CO A, which later becomes citric acid, which is then broken down, CO2 is related and electrons are transferred to energy carriers. One molecule of pyruvic acid gives 4 molecules of NADH, 1 molecule of FADH2 & 1 molecules of ATP.

In Figure 8-2, which of these processes occurs in the cytosol?

Stage A

In Figure 8-2, which process involves chemiosmotic phosphorylation?

Stage D

Which pathways does the body use to release energy during exercise? Discuss these pathways in terms of a footrace.

The first few seconds of a race ATP that the muscle cells already have on hand are used. Then, the muscle cells begin producing ATP by lactic acid fermentation—this would be around the Minute mark. After about 90 seconds, however, cellular respiration is the only way to generate a continuing supply of ATP.

ATP is produced in all stages of cellular respiration. Which two statements describe the process of ATP synthesis in the electron transport chain?

The high concentration of hydrogen ions in the intermembrane space allows them to diffuse across the membrane into the matrix.

Mariana eats an orange. Which statement describes the ultimate source of the energy that her body receives when she digests the orange?

The light energy that originates from the sun provides the energy to grow oranges, which contain macromolecules.

What would determine whether acetyl CoA or ethanol is produced?

The presence of oxygen

Compare photosynthesis with cellular respiration.

The products of one are the reactants for the other. (this works both ways)

People who suffer from a heart attack often have an increased ratio of lactic acid to pyruvic acid in their hearts. What does this observation say about the availability of oxygen in the heart muscle cells of someone who has had a heart attack? How could you use this information to screen people who might be at risk for a heart attack?

There isn't enough O2 flow. Cells convert to lactic acid fermentation. You can use the info to test people's blood.

In Figure 8-3, why is space "d." necessary?

To provide a space for the buildup of H+ for chemiosmosis

In the process of glycolysis, four ATP molecules are synthesized from four ADP molecules. Why does glycolysis not yield four molecules of ATP?

Two ATP molecules are required to start the process.

Glycolysis is the first stage of cellular respiration and is an anaerobic process. During glycolysis, glucose is converted to two molecules of pyruvic acid. How is glycolysis kept functioning during cellular respiration?

Two molecules of ATP from the cell are invested at the beginning of the process of glycolysis.

Savannah is asked to explain the locations of the stages of cellular respiration. What location should she give for the site of the Krebs cycle reactions?

the matrix of the mitochondria

Look at the diagram. A product of cellular respiration is ____________, which can escape from the test tubes through the ____________,. A reactant of cellular respiration is ____________,, which will be used up. Plants, like animals, need energy for ____________,]. The difference is that plants first ____________, food, then undergo cellular respiration, whereas animals must ____________, food, then undergo cellular respiration to make the energy from food available.

carbon dioxide, pipettes, oxygen, growth and reproduction, make, eat

Fermentation is a chemical reaction that takes place in the ____________ and occurs when oxygen is ____________. Byproducts of fermentation may include ____________ or ____________. Fermentation yields ____________ ATP than the electron transport chain.

cytoplasm, not available, alcohol, lactic acid, much less

In Figure 8-3, letter "a." is pointing to the location of the

electron transport chain

Which of these pairs of processes are anaerobic?

fermentation and glycolysis

The correct sequence of steps in the aerobic metabolic breakdown of glucose is

glycolysis-preparatory reaction-citric acid cycle-electron transport system

Marathon runners have a much higher percentage of "slow twitch" fibers in their muscles, which make it possible for them to run long distances at a steady pace. On the other hand, sprinters' muscles are composed mostly of "fast twitch" fibers, which allow to allow for intense bursts of exertion. Therefore, ____________ have more ____________ in their muscles to allow for greater ____________ production in long endurance runs.

marathon runners, mitochondria, ATP

What would happen if all the energy in glucose were released in just one step instead of gradually as it is in cellular respiration? How is the gradual process of cellular respiration advantageous to the cell?

process beings with glycolysis... releases only a small amount of energy. if oxygen is present, glycolysis leads to two other pathways that release a great deal of energy. if oxygen is not present, glycolysis goes in a different pathway.

The Krebs cycle consists of many small steps, each catalyzed by an enzyme. What is another name for the Krebs cycle?

the citric acid cycle

Why does lactic acid fermentation "kick in" during a sprint race?

when the body lacks oxegyn it kicks in atp to help out the body and help breathe