Biology in Focus Textbook: Chapter 7 - Cellular Respiration and Fermentation

Glycolysis harvests chemical energy by...

Oxidizing glucose to pyruvate

Catabolic pathways yield...

Energy by oxidizing organic fuels

How does the catabolic pathways of glycolosis and the citric acid cycle intersect with anabolic pathways in the metabolism of a cell?

ATP produced from catabolic pathways is used to drive anabolic pathways. Also, many intermediates of glycolysis and the citric acid cycle are used in the biosynthesis of a cell's molecules.

Consider the NADH formed during glycolysis. What is the final acceptor for its electrons during alcohol fermentation, lactic acid fermentation, and during aerobic respiration?

Alcohol fermentation: Pyruvate derivative Lactic Acid fermentation: Pyruvate Aerobic respiration: Oxygen

Compare and contrast anaerobic and aerobic respiration

Both include glycosis, the citric acid cycle, and oxidative phosphorylation. In aerobic respiration: the final electron receptor is molecular oxygen (O2) In anaerobic respiration: The final electron receptor is a different substance

What processes in your cells produce the CO2 that you exhale?

CO2 is released from the pyruvate that is the end product of glycolysis. CO2 is also released during the citric acid cycle.

Fermentation and anaerobic respiration enable...

Cells to produce ATP without the utilization of oxygen

What happens during oxidative phosphorylation?

Chemosmosis couples electron transport to ATP synthesis

The ETC is common to both ______________ and ____________ of a glucose molecule.

Fermentation , Cellular respiration

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the...

H+ concentration gradient across the membrane holding ATP synthase

What is the difference in oxidative phosphorylation and substrate-level phosphorylation?

Most ATP is produced in oxidative phosphorylation, in which the energy released from its ETC is used to produce a lot of ATP. Substrate-level phosphorylation is a direct transfer of a completed phosphate group from an intermediate substrate. This can occur in glycolosis or the citric acid cycle.

Name the molecules that converse most of the energy from redox reactions of the citric acid cycle. How is this energy converted to a form that can be used to make ATP?

NADH and FADH2; the energy is converted to a form that will assist ATP synthesis by donating electrons to the electron transport chain

During an intense exercise, can a muscle cell use fat as a concentrated source of chemical energy?

Only a small amount can be oxidixed.

What is the process of aerobic respiration?

Organic compounds + oxygen >>> Carbon dioxide + water + energy

The final electron receptor of the ETC that functions in aerobic oxidative phosphorylation is...

Oxygen

What is the oxidizing agent in... Pyruvate + NADH + H+ >>> Lactate + NAD+

Pyruvate

In the mitochondria, exergonic redox reactions...

Reduce carbon atoms to carbon dioxide

What molecular products indicate the complete oxidation of glucose during cellular respiration?

Release of six CO2 molecules.

Membranes must be fluid to function properly. How does the operation of the ETC support that assertion?

Some components need to be able to diffuse within the membrane. If the membrane was a solid, it would not be able to diffuse within a rigid or locked substance.

Name and describe two ways in which ATP is made during cellular respiration. During what stage(s) does each type occur?

Substrate level phosphorylation (in glycosis and citric acid cycle which involves direct transfer of a phosphate group from an organic substrate to ADP by an enzyme) Oxidative phosphorylation (third stage of cellular respiration which involves the synthesis of ATP from ADP and inorganic phosphate and is powered by the redox reactions of the electron transport chain)

A glucose-fed yeast cell is moved from an aerobic environment to an anaerobic one. How would it's rate of glucose consumption change if ATP were to be generated at the same rate?

The cell in an anaerobic environment would need to consume glucose at a rate of about 16 times the consumption rate within an aerobic environment (2 ATP generated by fermentation while 32 ATP generated by cellular respiration)

Most CO2 from catabolism is released during...

The citric acid cycle

What happens after pyruvate is oxidized?

The citric acid cycle completes the energy-yielding oxidation of organic molecules

What makes fats much better for fuel in comparison to a carbohydrate?

The fat is much more reduced and have higher energy levels due to their electrons being equally shared as opposed to carbohydrates that unequally share electrons.

What is the mechanism by which ATP synthase produces ATP? Where is ATP synthase located?

The flow of H+ through ATP synthase exposes catalytic sites that produce ATP from originating ADP and an intermediate phosphate. This process can occur in the plasma membrane, inner mitochondrial membrane, and chloroplast.

When electrons flow along the ETC of the mitochondria, what changes?

The pH (hydrogen ion concentration) increases

True or false: Glycolysis and the citric acid cycle connect to many other metabolic pathways

True

When might your body synthesize fat molecules?

When you consume more food necessary for metabolic processes, your body synthesize remaining fats as a way of storing energy for later metabolic processing.