Bios 1700 Chapter 7

Made using Ch. 7 Study Guide

What does OILRIG stand for in redox reactions?

Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons).

What happens to carbon during cellular respiration?

It is oxidized (loses electrons and energy) as glucose becomes CO₂.

What happens to oxygen during cellular respiration?

It is reduced (gains electrons and energy) as O₂ becomes H₂O.

In redox reactions, are oxidation and reduction separate?

No, they are always coupled — one molecule loses electrons while another gains them.

Why is oxygen important in redox reactions involving biological molecules?

Due to its high electronegativity, oxygen pulls electrons, making it reduced.

What are the reduced forms of electron carriers?

NADH (from NAD⁺) and FADH₂ (from FAD) — both carry energy.

What is the chemical reaction to form NADH?

NAD⁺ + H⁺ + 2e⁻ → NADH

What is the chemical reaction to form FADH₂?

FAD + 2H⁺ + 2e⁻ → FADH₂

Where does glycolysis occur and what are its products?

In the cytoplasm. It produces 2 pyruvate, 2 NADH, 4 ATP (net gain of 2 ATP after using 2).

What happens to pyruvate in anaerobic conditions?

It undergoes fermentation instead of entering the mitochondria.

What is the starting molecule of the citric acid cycle?

Acetyl-CoA

What are the energy products of the citric acid cycle?

ATP, NADH, and FADH₂; waste product: CO₂.

What is the role of NADH and FADH₂ in the electron transport chain (ETC)?

They donate electrons to ETC complexes, enabling proton pumping.

Which ETC complexes are proton pumps?

Complex I, Complex III, and Complex IV.

What electron carriers exist in the mitochondrial membrane?

Coenzyme Q (CoQ) and cytochrome c.

Where do electrons enter and exit the ETC?

Enter at Complex I (NADH) and II (FADH₂); exit at Complex IV, reducing O₂ to H₂O.

What is the role of ATP synthase in oxidative phosphorylation?

Converts proton gradient (potential energy) into ATP (chemical energy).

Which subunits of ATP synthase are involved in ATP production?

F₀ (channel for protons) and F₁ (catalytic ATP synthesis).

Why is the process called oxidative phosphorylation?

Because it uses oxidation of electron carriers and results in phosphorylation of ADP to ATP.

Where do the 4 stages of cellular respiration occur?

Glycolysis: Cytoplasm; Pyruvate oxidation & Citric acid cycle: Mitochondrial matrix; ETC & Oxidative phosphorylation: Inner mitochondrial membrane

What happens to cellular respiration when ATP is abundant?

Negative feedback inhibits key enzymes; the process slows down.

What happens when ADP levels are high?

Positive feedback accelerates cellular respiration to produce more ATP.

What does beta-oxidation break down and produce?

Breaks down fatty acids into acetyl-CoA and electron carriers (NADH, FADH₂).

What happens to acetyl-CoA after beta-oxidation?

It enters the citric acid cycle to generate ATP and other energy carriers.

In cellular respiration, carbon in glucose is ___ because it ___ electrons.

Oxidized; loses

Oxygen in O₂ is ___ because it ___ electrons to form H₂O.

Reduced; gains

The breakdown of glucose to CO₂ in cellular respiration is an example of (catabolism/anabolism).

Catabolism

Electrons from NADH and FADH₂ run ___ pumps in the ETC. These are complexes ___, ___, and ___.

Proton; I, III, IV

Electrons exit the ETC by ___ oxygen to form ___.

Reducing; H₂O

In β-oxidation, fatty acids are broken into ___ and generate ___.

Acetyl-CoA; NADH and FADH₂

A mouse with a faulty F₀ subunit of ATP synthase would be:

Skinny and hypermetabolic; inefficient ATP production leads to more energy being burned to compensate.

'Stick' the skinny mouse has a mutant phosphofructokinase that doesn't bind ATP or citrate. Why is he skinny?

Without feedback inhibition, glycolysis runs excessively, burning more glucose and preventing fat storage.