Cellular Respiration and Fermentation

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Questions and Answers

How much ATP does aerobic respiration produce?

38 ATP

How much ATP does anaerobic respiration produce?

2 ATP

How much ATP does fermentation produce?

none

How do organisms generate energy without oxygen present?

Fermentation Signup and view all the answers

What is fermentation?

a metabolic process that converts NADH and pyruvate back to NAD+ and an organic molecule Signup and view all the answers

What does fermentation use instead of an electron transport chain to generate ATP?

Substrate-Level Phosphorylation Signup and view all the answers

What is the final acceptor for NADH electrons during fermentation?

Pyruvate Signup and view all the answers

What are the two common types of fermentation?

Alcohol Fermentation and Lactic Acid Fermentation Signup and view all the answers

Define alcohol fermentation.

a process that converts sugars into cellular energy Signup and view all the answers

What are the byproducts of alcohol fermentation?

Ethanol and Carbon Dioxide Signup and view all the answers

What uses alcohol fermentation?

Yeast Signup and view all the answers

Define lactic acid fermentation.

when pyruvate is reduced by NADH to form lactic acid Signup and view all the answers

What uses lactic acid fermentation?

Fungi, Bacteria and Human Muscle Cells Signup and view all the answers

Define lactate dehydrogenase.

an enzyme that catalyzes the conversion of lactate to pyruvic acid and back Signup and view all the answers

Define obligate anaerobes.

organisms that carry out only fermentation or anaerobic respiration Signup and view all the answers

Define facultative anaerobes.

organisms that may use either aerobic or anaerobic processes depending on the presence of oxygen Signup and view all the answers

How do carbohydrates enter the catabolic pathway?

most carbohydrates enter during glycolysis Signup and view all the answers

How do lipids enter the catabolic pathway?

Beta Oxidation Signup and view all the answers

Define beta oxidation.

the catabolic process of breaking down fatty acids to generate acetyl-CoA Signup and view all the answers

Where does beta oxidation occur in prokaryotes?

In the cytosol Signup and view all the answers

Where does beta oxidation occur in eukaryotes?

In the mitochondria Signup and view all the answers

How is the activity of a pathway controlled?

Pathways are regulated through enzymes Signup and view all the answers

How are the enzymes that control metabolic pathways regulated?

by the binding of regulatory molecules at allosteric sites Signup and view all the answers

What are two ways that glycolysis is regulated?

Phosphofructokinase and Pyruvate Dehydrogenase Signup and view all the answers

Define feedback regulation.

the regulation of a process by its output Signup and view all the answers

Define feedback inhibition.

a method of metabolic control using end products as inhibitors in a pathway Signup and view all the answers

Study Notes

ATP Production

Aerobic Respiration generates 38 ATP from one glucose molecule.
Anaerobic Respiration produces only 2 ATP per glucose.
Fermentation does not yield additional ATP as NADH produced in glycolysis is fully consumed.

Fermentation Process

Fermentation extracts energy from food by producing ATP without oxygen.
It converts NADH and pyruvate back to NAD+ and an organic molecule to sustain glycolysis.
Uses Substrate-Level Phosphorylation to generate ATP instead of an electron transport chain.
The final electron acceptor for NADH during fermentation is pyruvate.

Types of Fermentation

Common types include Alcohol Fermentation and Lactic Acid Fermentation.
Alcohol Fermentation converts sugars into energy, producing ethanol and carbon dioxide as byproducts.
Lactic Acid Fermentation forms lactic acid from pyruvate with NADH; no oxygen is required.

Applications of Fermentation

Alcohol Fermentation is utilized by yeast in producing alcoholic beverages, ethanol fuel, and bread.
Lactic Acid Fermentation is used by fungi, bacteria, and human muscle cells under anaerobic conditions.

Enzymes and Pathways

Lactate dehydrogenase catalyzes the conversion of lactate to pyruvic acid and plays a role in regenerating NAD+.
Obligate Anaerobes rely solely on fermentation or anaerobic respiration and are harmed by oxygen.
Facultative Anaerobes can generate ATP via aerobic respiration when oxygen is available but switch to anaerobic methods when it is not.

Catabolism and Lipid Metabolism

Carbohydrates typically enter cellular respiration through glycolysis.
Lipids enter via Beta Oxidation, breaking down fatty acids into acetyl-CoA for the Citric Acid Cycle.
Beta Oxidation occurs in the cytosol of prokaryotes and in mitochondria of eukaryotes.

Regulation of Metabolic Pathways

Pathway activity is modulated via enzyme regulation at allosteric sites by regulatory molecules.
Phosphofructokinase and Pyruvate Dehydrogenase are key enzymes in glycolysis regulation.
Feedback Regulation utilizes the end product of a pathway to control its own pathway activity.
Feedback Inhibition occurs when a pathway's end product inhibits an enzyme within that same pathway.

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Description

This quiz focuses on ATP production in cellular respiration, highlighting differences between aerobic respiration, anaerobic respiration, and fermentation. It involves key concepts and metrics related to ATP yield from glucose in various metabolic pathways. Test your understanding of these essential biochemical processes.