Biology Chapter 9 - Cellular Respiration Flashcards

Questions and Answers

What is aerobic respiration?

A process that does not require O2

Inefficient metabolic process

A process that requires O2 (correct)

Only used by bacteria

What is anaerobic respiration?

Process that uses O2

Used mainly by bacteria in O2-deficient environments (correct)

An efficient metabolic process

Similar to aerobic respiration (correct)

What is fermentation?

Only occurs in aerobic conditions

Uses O2 to generate ATP

An efficient process that requires O2

An inefficient process used when other pathways cannot be used (correct)

What is the lifeline of energy?

Energy flows into an ecosystem as sunlight and leaves as heat. Signup and view all the answers

Provide the photosynthesis equation.

6 CO2 + 12 H2O → C6H12O6 + 6 H2O + 6 O2 Signup and view all the answers

What is the key energy-storing molecule?

Glucose Signup and view all the answers

What is the formula for respiration?

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP Signup and view all the answers

What does glycolysis break glucose down into?

Pyruvate Signup and view all the answers

How many ATPs are produced per glucose in respiration?

Approximately 30 Signup and view all the answers

Where does glycolysis occur?

Cytosol Signup and view all the answers

Glycolysis requires oxygen.

False Signup and view all the answers

Where does the Krebs cycle take place?

The mitochondria Signup and view all the answers

How many ATP does the Krebs cycle produce?

2 molecules of ATP Signup and view all the answers

What is FAD reduced to in the Krebs cycle?

FADH2 Signup and view all the answers

What is oxidative phosphorylation?

The electron transport chain and chemiosmosis Signup and view all the answers

Where are NADH and FADH2 oxidized in oxidative phosphorylation?

ETC (electron transport chain) Signup and view all the answers

How many ATP does oxidative phosphorylation produce?

32-34 Signup and view all the answers

What does chemiosmosis produce?

ATP Signup and view all the answers

What is the final electron acceptor in respiration?

O2 Signup and view all the answers

What method of metabolic control is feedback inhibition?

Feedback inhibition is when the end product of a metabolic pathway acts as an inhibitor. Signup and view all the answers

What is the switch enzyme in glycolysis?

Phosphofructokinase Signup and view all the answers

Study Notes

Cellular Respiration Overview

Aerobic Respiration: An efficient energy production process requiring oxygen, utilized by most organisms, also known as cellular respiration.
Anaerobic Respiration: Energy production methods that do not involve oxygen, mainly employed by bacteria in oxygen-poor environments.
Fermentation: Inefficient energy generation used when anaerobic pathways are necessary or ATP is needed rapidly without oxygen.

Energy Flow in Ecosystems

Energy enters ecosystems as sunlight and exits as heat.
Key Energy-Storing Molecule: Glucose is essential for energy storage in biological systems.

Key Equations

Photosynthesis Equation: 6 CO2 + 12 H2O → C6H12O6 + 6 H2O + 6 O2
Respiration Equation: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP

Electron Transfer and Energy

Oxidized: A substance that has lost electrons, whereas a Reduced substance has gained electrons.
Dehydrogenation Reactions: Transfer hydrogen to NAD+ or FAD during redox reactions.
Substrate-Level Phosphorylation: Direct phosphorylation of ADP or GDP through coupled reactions.

Stages of Cellular Respiration

Four Stages: Glycolysis, Pyruvate Oxidation, Krebs Cycle, Oxidative Phosphorylation.
Glycolysis Location: Occurs in the cytosol and does not require oxygen.
Products of Glycolysis: Breaks glucose down into two pyruvate molecules, yielding two ATP.

Pathways and Processes

Energy Investment Phase: Consumes two ATPs to yield two G3P molecules.
Energy Payoff Phase: Produces four ATPs, along with two Pyruvates and NADH.
Pyruvate Oxidation: Converts pyruvate into acetyl-CoA.

Krebs Cycle

Alternative Names: Citric Acid Cycle, Tricarboxylic Acid Cycle, TCA Cycle.
Krebs Cycle Location: Takes place in the mitochondria, producing two ATP molecules per cycle.
FAD Reduction: FAD is reduced to FADH2 during the Krebs Cycle.

Oxidative Phosphorylation

Involves the electron transport chain (ETC) and chemiosmosis, regenerating the energy charge of NADH and FADH2.
ATP Production: 32-34 ATP molecules produced due to the proton gradient established during this process.
Location of ETC: Takes place in the inner membrane of mitochondria, where H+ ions accumulate in the intermembrane space.

Chemiosmosis and ATP Synthesis

ATP Synthase: Enzyme allowing transportation of protons down the concentration gradient to synthesize ATP.
Efficiencies of Electron Carriers: Oxidation of NADH yields approximately 3 ATP, while oxidation of FADH2 yields about 2 ATP.

Final Electron Acceptor

Oxygen (O2): Serves as the final electron acceptor in the electron transport chain, completing the respiration process.

Metabolic Control

Feedback Inhibition: A regulatory mechanism where the end product of a metabolic pathway inhibits an enzyme within that pathway.
Phosphofructokinase: Acts as a key regulatory enzyme in glycolysis, influencing the pathway based on cellular energy demands.

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Description

Test your knowledge with these flashcards on cellular respiration concepts from Biology Chapter 9. Learn the differences between aerobic and anaerobic respiration, along with their implications for various organisms. Perfect for students looking to reinforce their understanding of key biological processes.