C1.2 Cellular respiration

What are the components of ATP?

Adenine, ribose, and 3 phosphate groups.

What is the purpose of ATP in the cell?

It supplies immediate energy for cellular work.

What is the chemical equation for ATP hydrolysis?

ATP -> ADP + Pi + energy

What is phosphorylation in the context of ATP?

ATP donates a phosphate group (Pi) to targets to make them more reactive.

How is ATP maintained in the cell?

It is constantly recycled by respiration (and photosynthesis in plants).

How does ATP support active transport?

It powers Na+/K+ pumps and proton pumps.

Give examples of biosynthesis powered by ATP.

DNA/RNA polymerization and peptide bond formation.

How is ATP involved in cellular movement?

It powers the myosin power stroke and kinesin/dynein movement on microtubules.

What types of cell work are powered by ATP?

Vesicle trafficking, mitosis, cytokinesis, endocytosis, exocytosis, and chromosome movement.

Which process releases energy from ATP?

Hydrolysis releases energy.

Which process creates ATP and requires energy?

Condensation makes ATP.

What are the two ways ATP is made?

Substrate-level phosphorylation and oxidative phosphorylation.

What is the general definition of cell respiration?

The controlled oxidation of organic compounds to make ATP.

Where does glycolysis occur?

In the cytosol.

What happens to pyruvate if oxygen is present?

It proceeds to the link reaction, Krebs cycle, and ETC in the mitochondrion.

What happens if oxygen is absent after glycolysis?

Fermentation occurs to regenerate NAD+.

Does aerobic respiration require oxygen?

Yes, it is required.

Does anaerobic respiration in humans require oxygen?

No, it is not required.

Where does aerobic respiration take place?

In the mitochondrion.

Where does anaerobic respiration take place in humans?

In the cytosol.

What substrates can be used for aerobic respiration?

Glucose, lipids, and amino acids.

What substrate is used for anaerobic respiration?

Glucose only.

What is the relative ATP yield per glucose for aerobic respiration?

High (approximately 30 ATP).

What is the relative ATP yield per glucose for anaerobic respiration?

Low (2 ATP).

What are the end-products of aerobic respiration?

CO2 and H2O.

What is the end-product of anaerobic respiration in humans?

Lactate.

How does temperature affect the rate of cell respiration?

Rate increases to an optimum, then decreases due to enzyme denaturation.

How does oxygen availability affect respiration?

It limits the rate of aerobic respiration.

How do different substrate types affect the rate of cell respiration

Carbohydrates are fast; lipids are slow but energy-rich.

How does pH affect respiration?

Enzymes involved have narrow pH optima.

How can the rate of respiration be measured?

Via oxygen consumption or carbon dioxide production.

What are the inputs and net ATP of Glycolysis?

Inputs: Glucose, 2 ATP, 2 NAD+; Net ATP: 2.

Where do the Link reaction and Krebs cycle occur?

In the mitochondrial matrix.

What are the outputs of the Link reaction per glucose?

2 acetyl-CoA, 2 CO2, 2 NADH.

What are the outputs of the Krebs cycle per glucose?

4 CO2, 6 NADH, 2 FADH2, 2 ATP.

Where does the ETC/Oxidative Phosphorylation occur?

The inner mitochondrial membrane.

What is the final net ATP yield for the ETC/Oxidative Phosphorylation stage?

28-32 ATP.