Biology – Chapter 8: Cellular Respiration – Study Guide

Cellular respiration
Metabolic reactions that use the energy from carbohydrate, fatty acid, or amino acid breakdown to produce ATP molecules

Chemical equation for cellular respiration
C6H12O6+602 → 6CO2 + 6H2O + cellular energy

Where does glycolysis take place?
In the cytoplasm

Where do the citric acid cycle and the electron transport cycle take place?
In the mitochondria

Oxidation reaction
loss of electrons/hydrogen

Reduction reaction
gain of electrons/hydrogen

Endergonic reaction

phosphate group is attached to a molecule

Acetyl CoA
2 carbon molecules

NAD+ is a coenzyme that accepts electrons and hydrogen ions to become NADH, which carries electrons to the electron transport chain


3 carbon molecule

Released energy from food molecules when no oxygen is present

Folds of inner membrane

List and briefly describe the phases of cellular respiration
Glycolysis, preparatory reaction, citric acid cycle, electron transport chain

How many ATP are produced during glycolysis? The citric acid cycle? The electron transport chain?
4; 2; 32-34

Chemical equations for cellular respiration and photosynthesis
C6H12O6 + 6O2 → 6CO2 + 6H2O + cellular energy
6CO2 + 6H2O + cellular energy → C6H12O6 + 6O2

Define cellular respiration and respiration
respiration can mean breathing–exchange of oxygen and carbon dioxide in the lungs– or cellular respiration–carbs, ect broken down and cellular energy produced in form of ATP

Where does the process of cellular respiration take place?
Begins in cytoplasm and complete in mitochondria

What are the four phases of cellular respiration?
Glycolysis, preparatory cycle, citric acid cycle, electron transport chain

Do plant and animal cells undergo cellular respiration?
No, only animals

How do animal cells receive oxygen and glucose?
Delivered to cells through the bloodstream

All cells undergo ___. Is oxygen required for this phase?
Glycolysis; no

What takes place in the aerobic metabolic pathway and the anaerobic metabolic pathway?
Cellular respiration takes place in the aerobic metabolic pathway; fermentation takes place in the anaerobic metabolic pathway

What undergoes lactic acid and alcohol fermentation?
Animal muscles, fungi, and some bacteria undergo lactic acid fermentation; yeast undergoes alcohol fermentation

Describe oxidation and reduction during cellular respiration. (where have the hydrogen atoms moved?)

How many carbons does glucose contain?

List the steps of the energy-investment stage of glycolysis. How much energy is used?
1. Phosphorylation of glucose produces: 6-C + P
2. 2nd phosphorylation of glucose produces: P + 6-C + P
3. 6-C molecules splits into two 3-C molecules
Uses 2 ATP

During the energy-harvesting steps, how many ATP are produced? What is the net gain of ATP during glycolysis?
4 ATP; net gain of 2 ATP

Define and describe the function of NAD+ and NADH
NAD+: coenzyme that accepts electrons and hydrogen ions to become NADH
NADH: electron carrier; carries electrons to the electron transport chain

What are the end products of glycolysis?
4 ATP and 2 pyruvate molecules

What happens if oxygen is available after glycolysis? If not available?
If oxygen is available, the pyruvate molecules will enter the matrix of the mitochondria. If oxygen is not available, the pyruvate molecules undergo fermentation.

Describe the process of the preparatory cycle. Where does this take place?
1. Pyruvate bonds with coenzyme A
2. Acetyl CoA is produced (2-C molecules)
3. 2 carbon dioxide molecules and 2 NADH molecules released
Takes place in matrix of mitochondria

What takes place during the citric acid cycle (Kreb’s cycle)?
Acetyl CoA joins a 4-carbon molecule to become citrate (6-C)

Where does the citric acid cycle take place?
matrix of mitochondria

After two cycles, one molecule of glucose has been utilized. What are the final products after two turns of the citric acid cycle?
2 ATP, 4 carbon dioxide, 6 NADH, 2 FADH2

What is the function of FADH2?
To carry electrons to the electron transport chain (electron carrier)

Define chemiosmosis
uses an H+ gradient to drive ATP formation

Describe the process that takes place in the electron transport chain. How is ATP formed? Where is the area of high concentration of H+? Where is the area of low concentration of H+? Is energy required?
electrons move from one protein complex to the other and hydrogen ions are pumped from matrix into intermembrane space; as hydrogen ions flow down a concentration gradient from the intermembrane space into the mitochondrial matrix, ATP is synthesized by the enzyme ATP synthase. ATP leaves the matrix by way of a channel protein; by ATP synthase; intermembrane space; matrix; idk

How is ATP released into the cell? Is energy required?

How many net ATP molecules were produced during glycolysis? How many ATP molecules were produced during the citric acid cycle? How many ATP will be produced on the electron transport chain? What is the total number of ATP molecules produced during cellular respiration?
2; 2; 32-34; 36-38