Energy Flow in Living Systems

These flashcards cover key concepts about energy flow in living systems, including photosynthesis, cellular respiration, and the roles of ATP and other essential molecules.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.

Cellular Respiration

A set of metabolic reactions that convert biochemical energy from nutrients into ATP, releasing waste products.

ATP (Adenosine Triphosphate)

The primary energy carrier in all living organisms; it stores and transports chemical energy within cells.

Autotrophs

Organisms that produce their own food from inorganic substances; examples include plants and certain bacteria.

Heterotrophs

Organisms that cannot produce their own food and rely on consuming other organisms for energy.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, producing a small amount of ATP.

Krebs Cycle (Citric Acid Cycle)

A series of enzyme-driven reactions that takes place in the mitochondria, generating energy through the oxidation of acetyl-CoA.

Electron Transport Chain

A series of protein complexes located in the inner mitochondrial membrane that generates ATP through oxidative phosphorylation.

Redox Reaction

A chemical reaction involving the transfer of electrons between two species; oxidation entails losing electrons, while reduction is gaining electrons.

Photolysis

The chemical separation of molecules by the action of light, particularly in the context of splitting water in photosynthesis.

Mutualistic Relationship

A symbiotic relationship where both parties benefit; for example, plants and animals exchanging oxygen and carbon dioxide.

Photophosphorylation

The process of converting ADP to ATP using the energy of sunlight, primarily occurring during the light reactions of photosynthesis.

Thylakoids

Membrane-bound compartments inside chloroplasts where the light-dependent reactions of photosynthesis take place.

Chlorophyll a

The main photosynthetic pigment found in green plants that absorbs primarily blue and red light.

Accessory Pigments

Pigments other than chlorophyll a (such as carotenoids) that assist in capturing light for photosynthesis.

NADPH (Nicotinamide Adenine Dinucleotide Phosphate)

An electron carrier that stores energy in the form of high-energy electrons, produced during the light reactions of photosynthesis.

Chemiosmosis

The movement of protons across a selectively permeable membrane, down their electrochemical gradient, to synthesize ATP.