LESSON 5: Cellular Respiration

What is cellular respiration?

Cells extract energy from food to generate ATP through glucose catabolism.

How does the transfer of energy relate to the movement of electrons in cellular respiration?

Energy is transferred incrementally alongside the movement of electrons, allowing for small packages of food energy to be captured in ATP's phosphate bonds.

Where does cellular respiration occur in eukaryotes?

Mitochondrion

What are REDOX reactions?

Chemical reactions where electrons are transferred between molecules.

Molecules that donate electrons in a redox reaction are called?

Reducing agents

Molecules that accept electrons in a redox reaction are called?

Oxidizing agents

What are the two states of nicotinamide adenine dinucleotide (NAD)?

It can occur in an oxidized state (NAD+) or a reduced state (NADH).

What is the exergonic process that provides energy for a coupled endergonic reaction?

Hydrolysis of ATP to ADP + Pi.

What is the loss of a phosphate group from a molecule called?

Dephosphorylation

What is the process of adding a phosphate group to a molecule called?

Phosphorylation

What are the two ways that the energy required to generate ATP can come from?

Substrate-level phosphorylation and chemiosmosis.

What are the 4 metabolic pathways of cellular respiration?

Glycolysis, Pyruvate oxidation, Citric Acid Cycle, Oxidative Phosphorylation

Where does glycolysis occur?

Cytoplasm

In eukaryotes, where does pyruvate oxidation occur if oxygen is present?

Mitochondria

Where does the Citric Acid Cycle (Krebs Cycle) occur?

Mitochondrial matrix

Where does Oxidative Phosphorylation (ETC and Chemiosmosis) occur?

Cristae (mitochondria)

What are the outputs of Glycolysis?

2 Pyruvate, 2 NADH, 4 ATP, 2 ADP

What is the net ATP production of glycolysis?

2 ATP

What are the outputs of pyruvate oxidation?

2 CO2, 2 NADH, 2 acetyl CoA

What is formed when the acetyl group from acetyl CoA is transferred to oxaloacetate?

Citrate

What is the final product of the citric acid cycle?

Oxaloacetate

What are the outputs per glucose after Glycolysis and the Citric Acid Cycle?

4 ATP, 6 CO2, 10 NADH, 2 FADH2

In which pathway does most of the ATP production occur?

Oxidative Phosphorylation

What are the 2 parts of oxidative phosphorylation?

Electron transport chain and chemiosmosis

Where is the electron transport chain located?

Inner mitochondrial membrane.

What carries e- from complexes I and II to complex III in the electron transport chain?

Ubiquinone (Q)

How does chemiosmosis generate ATP?

Uses kinetic energy from protons falling down its gradient to form ATP from ADP + Pi

How many ATP are approximately generated by cellular respiration?

30-36 per glucose