Metabolism Mastery Overview

This set of flashcards covers key terms and concepts related to cellular metabolism, glycolysis, Krebs cycle, electron transport chain, and the role of ATP, enzymes, and photosynthesis.

Metabolism

All chemical reactions occurring within the body.

Catabolic Pathways

Metabolic pathways that breakdown complex molecules into simpler building blocks, releasing energy and heat.

Anabolic Pathways

Metabolic pathways that use energy and building blocks to construct/synthesize macromolecules.

Enzyme

A protein catalyst that speeds up chemical reactions by lowering the activation energy.

Active Site

The region on an enzyme where substrates bind and a reaction occurs.

Coenzymes

Small molecules that assist enzymes in catalyzing reactions; examples include NAD⁺ and FAD.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells, which releases energy upon hydrolysis.

ATP → ADP + Pi

A reaction that supplies energy

ADP + Pi + Energy → ATP

A reaction that regenerates ATP

ATP Cycle

The process of converting ATP to ADP and inorganic phosphate, and regenerating ATP using energy.

1. ATP is hydrolyzed into ADP + Pi

2. Myosin-ADP + Pi attaches to actin forming a cross bridge

3. Release of ADP and Pi cause a power stroke

4. New ATP binds causing myosin to detach

5. The cycle repeats

Cross-Bridge Cycle

The series of events in muscle contraction where myosin heads bind to actin, pivot, and generate force.

Glycolysis

The metabolic process that breaks down glucose into pyruvate, yielding a net gain of 2 ATP.

Krebs Cycle

A series of reactions in the mitochondrial matrix that further oxidizes pyruvate to produce ATP, NADH, and FADH₂.

General Enzyme Cycle

Substrate binds to empty Active Site

Enzyme-Substrate Complex forms, reaction occurs

Products are released, restoring the free enzyme

Inorganic Phosphate (Pi)

A free phosphate ion that combines with ADP to form ATP

Electron Transport Chain

The series of complexes that transfer electrons and create a proton gradient to produce ATP during oxidative phosphorylation.

Glucose

A six-carbon monosaccharide that is a primary energy source for cells.

Polysaccharides

Carbohydrates that are made up of long chains of monosaccharide units, used for energy storage (e.g. starch, glycogen) and structure (e.g. cellulose).

Storage Polysaccharides

Starch, Glycogen, and Cellulose

Photosynthesis

The process by which plants and some other organisms convert light energy into chemical energy in the form of glucose.

Cellular Respiration

The biochemical process in which cells convert glucose and oxygen into carbon dioxide, water, and ATP.

Enzyme-Substrate Complex

Formed when an enzyme binds to a substrate

A key step that allows enzymes to convert substrates into products

Makes the reaction faster and more efficient

Enzyme Specificity

Enzymes only match to particular/specific substrates

Phosphate Bonds

Stores high-energy electrons that break bonds to release energy for cellular work

Myosin

A family of motor proteins best known for their roles in muscle contraction and a wide range of other motility processes in eukaryotes

Glycogen Granules

Found in animal cells

Serve as cytoplasmic glucose reserves

Starch Granules

Found in plant chloroplasts

Converted to glucose