BISC 1005 Mastering Biology chapter 8

How many NADH are produced by glycolysis?

2

How many CO2 molecules are generated from each pyruvate that enters the mitochondria?

3

Which kind of metabolic poison would interfere with the glycolysis stage of cellular respiration?

An agent that closely mimics the structure of glucose but is not capable of being metabolized

Bacteria in our mouth feed off the sugars in foods that we eat. As these bacteria ferment the sugars, they generate a product that can cause dental cavities. What is this product?

Lactic acid

The inner membrane of the mitochondria can be compared functionally to the thylakoid membranes of the chloroplast because both contain a system for

electron transport

In the mitochondrial matrix reactions, the original carbons in pyruvate

end up in molecules of CO2

Where does the synthesis of pyruvate occur during glycolysis?

fluid portion of the cytoplasm

During glycolysis in the energy-investing stage, two ATP molecules are "spent" in order to convert glucose to the highly reactive molecule

fructose-1,6-bisphosphate.

what is the correct sequence of steps as energy is extracted from glucose during cellular respiration.

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

The final electron acceptor of cellular respiration is _____.

oxygen

In glycolysis, ATP molecules are produced by

substrate-level phosphorylation

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

substrate-level phosphorylation

In the Krebs cycle, electron carrier molecules are produced as a result of individual reactions. NADH molecules are oxidized as one chemical compound is converted to another, except during the conversion of:

succinate to fumarate.

How many high-energy molecules are produced in one round of the Krebs cycle?

three NADH, one FADH2, and one ATP

In glycolysis what starts the process of glucose breakdown?

ATP

Cyanide poisoning occurs because cyanide inhibits an enzyme in the electron transport pathway. Which of the following is the reason why cyanide poisoning becomes deadly?

ATP is no longer produced by chemiosmosis.

The products of the Krebs cycle include

ATP, CO2 and energy carriers

What are the products of the citric acid cycle (krebs cycle)?

ATP, NADH + H+, CO2, and FADH2

How does one account for the bubbles in a glass of beer or champagne?

Bubbles of CO2 were produced by yeast during anaerobic metabolism and were trapped in the bottle.

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

oxidative phosphorylation

If photosynthesis and respiration are almost symmetrical processes, how is energy lost in the process of converting sugar back into ATP?

Energy is lost as heat during the reactions of cellular respiration.

For each glucose that enters glycolysis, _____ NADH enter the electron transport chain.

For each glucose molecule that enters glycolysis, a total of 10 NADH are produced -- 2 are produced in glycolysis, 2 are produced in acetyl CoA production, and 6 are produced in the citric acid cycle.

Why do cells convert the energy stored in the bonds of glucose into energy stored in the bonds of ATP?

Glucose is not a usable energy source for most enzymes.

What would happen if a cell converted all of its NAD+ into NADH?

Glycolysis would stop due to lack of a reactant

Where is the majority of the usable energy found at the completion of glycolysis, acetyl CoA formation, and the Krebs cycle?

NADH

Name products of glycolysis

NADH + H+, ATP, pyruvate, and water

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

NADH and FADH2 ... intermembrane space

What property of oxygen allows it to form bonds with the electrons found at the end of the electron transport chain?

Oxygen forms polar, low-energy bonds.

How many of the carbons originally present in glucose continue to other reactions after glycolysis?

Six carbons are left in pyruvate molecules.

Oxygen is necessary for cellular respiration because oxygen

combines with electrons and hydrogen ions to form water.

Why is the Krebs cycle called a cycle?

The final product of the process serves as an initial reactant in the process.

Which of the following uses alcohol fermentation in the absence of oxygen?

Yeast

What enters the Krebs cycle also known as the citric acid cycle?

acetyl CoA

We breathe more heavily during exercise because our cells

are producing more CO2

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

kinetic energy that is released as hydrogen ions diffuse down their concentration gradient

In muscle cells, fermentation produces _____.

lactate and NAD+

After fermentation in human cells, lactate is converted to pyruvate in the

muscles

Some people trying to lose weight have gone on the "Atkins diet," in which they eat mostly high-protein, low-carbohydrate foods such as meat, cheese, and eggs. The amino acids in these protein-rich diets, such as alanine, glycine, and serine, can be converted to pyruvate by deamination (removal of the amino group). Based on this scenario as well as your knowledge of cellular respiration, how many ATP, NADH, and FADH2 molecules will be generated from one molecule of alanine during the mitochondrial matrix reactions? Hint: Only consider the reactions from the point at which the alanine carbons enter cellular respiration.

one FADH2, four NADH, and one ATP