AI - Metabolism Fundamentals

A comprehensive set of vocabulary flashcards covering key concepts related to metabolism, ATP, cellular respiration, and their regulatory mechanisms.

What is metabolism?

Metabolism is the sum total of chemical processes in a living organism that result in growth, energy production, and waste elimination.

What is a metabolic pathway?

A metabolic pathway begins with a specific molecule and ends with a product, with each intermediate step catalyzed by a specific enzyme.

Catabolic pathways

Break down complex molecules into simpler compounds to release energy (e.g., cellular respiration).

Anabolic pathways

Consume energy to build complex molecules from simpler ones (e.g., protein synthesis from amino acids).

Exergonic reactions

Result in a net release of free energy and can occur spontaneously once activation energy is reached.

Endergonic reactions

Require a large input of energy to proceed and are non-spontaneous.

What is ATP?

ATP (Adenosine Triphosphate) is the 'energy currency' of the cell.

What is the chemical composition of ATP?

ATP consists of the sugar ribose, the nitrogenous base adenine, and three phosphate groups.

How does ATP power cellular work?

ATP powers work through energy coupling, using exergonic reactions to drive endergonic ones.

What happens when the terminal phosphate bond of ATP is broken?

Energy is released and the cell performs phosphorylation, transferring that phosphate group to another molecule.

How is ATP regenerated?

ATP is regenerated by adding an inorganic phosphate back to ADP, with energy coming from catabolic pathways.

What are the three stages of aerobic cellular respiration?

1. Glycolysis 2. Citric Acid Cycle (Krebs Cycle) 3. Oxidative Phosphorylation.

Describe Glycolysis (location, inputs, and outputs).

Located in the cytosol; splits one glucose into two pyruvates, uses 2 ATP and produces 4 ATP and 2 NADH.

What occurs during the Citric Acid Cycle?

Pyruvate is converted to Acetyl CoA, which then breaks down into CO2, yielding ATP, NADH, and FADH2.

What is the role of the Electron Transport Chain in Oxidative Phosphorylation?

NADH and FADH2 donate electrons, creating a proton (H+) gradient.

How does Chemiosmosis produce ATP?

H+ ions flow back across the membrane through ATP synthase, driving the phosphorylation of ADP to ATP.

What is the total ATP yield from one molecule of glucose?

Approximately 32 ATP molecules.

How do Anaerobic Respiration and Fermentation differ?

Anaerobic Respiration uses an electron transport chain with a final electron acceptor other than oxygen, while Fermentation does not use an electron transport chain.

What are the two main types of fermentation?

1. Alcohol Fermentation (converts pyruvate to ethanol and CO2) 2. Lactic Acid Fermentation (reduces pyruvate to lactate).

What is Feedback Inhibition in Glycolysis?

Phosphofructokinase (PFK) is inhibited by ATP and Citrate, and activated by AMP.

Analogy for ATP and Metabolism

Metabolism is like a factory's economy; catabolism generates ATP, while anabolism uses ATP to build machinery.