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What is the process called when a substance loses electrons?
What is the process called when a substance loses electrons?
Oxidation
Which of the following is NOT a stage of aerobic respiration?
Which of the following is NOT a stage of aerobic respiration?
Where does glycolysis take place in a eukaryotic cells?
Where does glycolysis take place in a eukaryotic cells?
Cytoplasm
Where does the Krebs cycle take place in a eukaryotic cells?
Where does the Krebs cycle take place in a eukaryotic cells?
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Where does the electron transport chain takes place in a eukaryotic cells?
Where does the electron transport chain takes place in a eukaryotic cells?
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What is the main product of glycolysis?
What is the main product of glycolysis?
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What is the final electron acceptor in aerobic respiration?
What is the final electron acceptor in aerobic respiration?
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What is the main product of the Krebs cycle?
What is the main product of the Krebs cycle?
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What is the main product of fermentation?
What is the main product of fermentation?
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Name two types of fermentation?
Name two types of fermentation?
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What is the name of the process that uses energy from a proton gradient to produce ATP?
What is the name of the process that uses energy from a proton gradient to produce ATP?
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What is the main difference between aerobic respiration and anaerobic respiration?
What is the main difference between aerobic respiration and anaerobic respiration?
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Fermentation produces more ATP than aerobic respiration.
Fermentation produces more ATP than aerobic respiration.
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Glycolysis takes place in the mitochondria.
Glycolysis takes place in the mitochondria.
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ATP is a product of all three stages of aerobic respiration.
ATP is a product of all three stages of aerobic respiration.
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Anaerobic respiration requires oxygen.
Anaerobic respiration requires oxygen.
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The electron transport chain generates a proton gradient across the inner mitochondrial membrane.
The electron transport chain generates a proton gradient across the inner mitochondrial membrane.
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The Krebs cycle directly produces ATP.
The Krebs cycle directly produces ATP.
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Fermentation uses an electron transport chain.
Fermentation uses an electron transport chain.
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Prokaryotes do not have mitochondria.
Prokaryotes do not have mitochondria.
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The process called chemiosmosis produces ATP using a proton gradient.
The process called chemiosmosis produces ATP using a proton gradient.
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The breakdown of glucose is an exergonic process.
The breakdown of glucose is an exergonic process.
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In fermentation, pyruvate is oxidized to acetyl-CoA.
In fermentation, pyruvate is oxidized to acetyl-CoA.
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The citric acid cycle produces more ATP than glycolysis.
The citric acid cycle produces more ATP than glycolysis.
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Anaerobic respiration occurs in the absence of oxygen.
Anaerobic respiration occurs in the absence of oxygen.
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ATP is used to store and transfer energy within cells.
ATP is used to store and transfer energy within cells.
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The electron transport chain is the final stage of both aerobic and anaerobic respiration.
The electron transport chain is the final stage of both aerobic and anaerobic respiration.
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Glycolysis is the only stage of cellular respiration that produces ATP.
Glycolysis is the only stage of cellular respiration that produces ATP.
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Fermentation is an inefficient process of energy production compared to aerobic respiration.
Fermentation is an inefficient process of energy production compared to aerobic respiration.
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The citric acid cycle is also known as the Krebs cycle.
The citric acid cycle is also known as the Krebs cycle.
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The electron transport chain uses a proton gradient across the mitochondrial membrane to produce ATP.
The electron transport chain uses a proton gradient across the mitochondrial membrane to produce ATP.
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During cellular respiration, glucose is reduced.
During cellular respiration, glucose is reduced.
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Study Notes
Biology ACST 112 - Chapter 6: How Cells Make ATP: Energy-Releasing Pathways
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Learning Objectives:
- Students will be able to write a summary reaction for aerobic respiration, identifying oxidized and reduced reactants.
- Outline and summarize the four stages of aerobic respiration.
- Determine the location of each stage in a eukaryotic cell.
- Define chemiosmosis and explain proton gradient formation across the inner mitochondrial membrane.
- Contrast and compare anaerobic respiration and fermentation, including ATP formation mechanisms, final electron acceptors, and end products.
Overview
- Living organisms gain energy from external sources.
- Some animals consume plants or other animals.
- Energy enters the ecosystem as sunlight and exits as heat.
- Photosynthesis creates organic molecules from CO₂ and H₂O, using energy from light.
- Cells use this energy stored in organic molecules to regenerate ATP, powering cellular work.
Catabolism and ATP Production
- Breakdown of organic molecules is exergonic (releases energy stored in ATP).
- This occurs through cellular respiration (aerobic or anaerobic).
- Aerobic respiration needs O₂.
- Anaerobic respiration does not require O₂ and can be fermentation.
- Aerobic respiration consumes organic molecules and O₂ to produce ATP.
- Anaerobic respiration resembles aerobic respiration but uses a different electron acceptor than O₂.
- Fermentation is a partial sugar degradation that takes place without O₂
Redox Reactions
- Redox reactions involve electron transfer between molecules.
- Oxidation is loss of electrons.
- Reduction is gain of electrons.
- C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (in the chemical bonds of ATP) - Summary of Glucose Oxidation
The Four Stages of Aerobic Respiration
- Glucose oxidation has four main stages: glycolysis, formation of acetyl CoA, citric acid cycle, and electron transport chain and chemiosmosis
- Glycolysis in the cytosol: breaks down glucose to pyruvate, forming 2 ATPs and 2 NADH
- Formation of acetyl CoA in the mitochondria: oxidizes pyruvate to Acetyl CoA, forming 2 NADH and releasing CO₂
- Citric acid cycle in the mitochondria: oxidizes acetyl CoA to CO₂, producing 2 ATP, 6 NADH, and 2 FADH₂.
- Electron transport chain and chemiosmosis in the mitochondria: uses electron carriers (NADH and FADH₂) to create a proton gradient across the inner mitochondrial membrane, generates 32-34 ATPs through chemiosmosis.
- Prokaryotes lack mitochondria, so these processes happen in the cytosol and associated with the cell membrane.
Glycolysis (Glucose Splitting)
- Glycolysis is the first step in cellular respiration.
- It's a series of 10 biochemical reactions.
- Glycolysis breaks down glucose into two three-carbon pyruvate molecules, extracting energy.
- This process occurs in the cytosol of all living cells.
- Glycolysis produces 2 ATP, 2 NADH, and 2 pyruvate molecules.
Formation of Acetyl Coenzyme A
- Each pyruvate enters the mitochondrion and is oxidized to a 2-carbon group (acetyl CoA).
- NADH is produced, and CO₂ is released as a byproduct.
The Citric Acid Cycle
- Acetyl CoA combines with oxaloacetate (a four-carbon molecule) to form citrate (a six-carbon molecule).
- The cycle regenerates oxaloacetate, releasing CO₂ as a waste product.
- Energy is captured as ATP and the reduced high-energy electron carriers NADH and FADH₂.
Electron Transport and Chemiosmosis
- Electrons from glucose are transferred to a chain of electron acceptors, culminating in oxygen reduction to water.
- Energy released from electron transfer pumps H⁺ ions across the inner mitochondrial membrane, creating a proton gradient.
- ATP synthase uses the energy stored in this gradient to produce ATP through chemiosmosis.
Summary of Glucose Aerobic Respiration
- Glycolysis produces 2 ATP, 2 NADH, and 2 pyruvate molecules.
- Formation of acetyl CoA produces 2 NADH and releases 2 CO₂.
- The citric acid cycle produces 2 ATP, 6 NADH, and 2 FADH₂ and releases 4 CO₂
- The electron transport chain and chemiosmosis produce 32-34 ATP.
- The overall total ATP yield is ~ 32-34 ATP.
Fermentation and Anaerobic Respiration
- Fermentation and anaerobic respiration enable ATP production without oxygen.
- Glycolysis occurs with or without O₂
- Anaerobic respiration uses an electron transport chain with an electron acceptor other than oxygen (e.g., sulfate).
- Fermentation is glycolysis coupled with reactions that regenerate NAD⁺, allowing glycolysis to continue.
Types of Fermentation
- Alcohol fermentation: Pyruvate is converted to ethanol in two steps (releasing CO₂).
- Yeast is used in brewing, winemaking, and baking.
- Lactic acid fermentation: Pyruvate is reduced to lactate by NADH (no CO₂ release).
- Used by some fungi, bacteria, human muscle cells, and human red blood cells.
Anaerobic Respiration
- Anaerobic respiration does not use oxygen but other inorganic molecules as the final electron acceptor.
- The process is similar to aerobic respiration, using an electron transport chain and chemiosmosis to produce ATP.
Fermentation vs. Aerobic Respiration
- Both use glycolysis to oxidize glucose to pyruvate.
- They differ in electron acceptors (organic molecule for fermentation, O₂ for aerobic respiration).
- Aerobic respiration produces significantly more ATP (30-32) than fermentation (2).
Energy Yield of Nutrients Other Than Glucose
- Many organisms use various nutrients (proteins, carbohydrates, fats) instead of glucose, which are converted to intermediates feeding into glycolysis or the citric acid cycle to generate ATP.
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Description
This quiz focuses on Chapter 6 of Biology ACST 112, covering the processes of aerobic respiration and ATP production. Students will explore the stages of aerobic respiration, understand chemiosmosis, and differentiate between anaerobic respiration and fermentation. Prepare to deepen your understanding of how cells generate energy!
