Ecology, Cellular Energetics, and Photosynthesis Review

Comprehensive vocabulary flashcards covering key definitions across ecology, cellular respiration, photosynthesis, and basic biochemistry.

Trophic level

The position an organism occupies in a food chain, food web, or ecological pyramid, based on how it gets food.

Biomass

The total mass of organic material from a living or recently living organism.

Fermentation

A metabolic process where tiny living organisms like bacteria and yeast break down sugars for energy without using oxygen.

Autotroph

An organism that creates its own food and organic nutrients from basic inorganic substances using energy from light or chemical reactions.

Heterotroph

A living thing that can't make its own food and must get its energy by eating other plants, animals, or organic matter.

Producer

An organism that makes its own food using energy and simple inorganic substances, rather than eating other living things.

Consumer

An organism that can't produce its own food and must obtain energy and nutrients by feeding on other plants, animals, or organic matter.

Food chain

A linear sequence of organisms in an ecosystem that shows how energy and nutrients move from one living thing to another as "who eats whom".

Food web

A natural network of interconnected food chains that show how energy and nutrients move among organisms in an ecosystem.

ATP Synthase

A large, membrane-bound enzyme complex that catalyzes the synthesis of ATP from adenosine diphosphate (ADP) and inorganic phosphate, driven by the flow of protons down an electrochemical gradient.

Calvin Cycle

A series of light-independent biochemical reactions that take place in the stroma of chloroplasts during photosynthesis, converting carbon dioxide into glucose and other carbohydrates.

Cellular Respiration

A metabolic process in which cells break down organic molecules (glucose) to release chemical energy and store it in adenosine triphosphate (ATP), while releasing carbon dioxide and water products.

Matrix

A term with different definitions depending on the specific field, most notably in math, bio, and geology.

Aerobic

Any biological, physiological, or chemical process that requires, utilizes, or occurs in the presence of free oxygen.

Anaerobic

Living, occurring, or operating in the absence of free or molecular oxygen.

Glycolysis

The splitting of sugar.

Krebs Cycle

A series of chemical reactions that cells use to break down food molecules and release energy.

Thylakoid

A membrane-bound, flattened disk or sac inside plant and algae chloroplasts and cyanobacteria that hosts the light-dependent reactions of photosynthesis.

Stroma

The supportive framework, matrix of a cell, tissue, or organ.

NADPH

Nicotinamide adenine dinucleotide phosphate; a critical coenzyme and electron donor used in cellular metabolism.

Light-dependent reactions

The initial phase of photosynthesis where chlorophyll absorbs solar energy to convert light energy into chemical energy in the form of ATP and NADPH, while splitting water molecules to release oxygen.

Light-independent reactions

A series of biochemical processes in photosynthesis that convert carbon dioxide and other compounds into glucose without directly requiring sunlight.

Photosystem

A functional and structural multi-protein complex embedded in photosynthetic membranes that absorbs light to drive photosynthesis.

Electron Transport Chain

A series of protein complexes and organic molecules embedded in a membrane that transfer electrons through a sequence of redox reactions to generate a proton gradient and drive the synthesis of ATP.

Products

A new substance formed as the result of a chemical reaction.

Activation Energy

The minimum amount of energy required to start a chemical reaction.

Catalyst

A substance that speeds up a chemical reaction by lowering the required activation energy without being consumed or permanently changed in the process.

Enzyme

Biological catalysts, usually made of proteins, that speed up chemical reactions in living things.

Substrate

A foundational surface on which an organism lives, or a target substance that an enzyme acts upon during a chemical reaction.

ATP

Adenosine triphosphate; the main energy-carrying molecule used in living cells.

Photosynthesis

The biological process by which green plants, algae, and some bacteria convert light energy into chemical energy.

Pigment

A material that changes the color of reflected or transmitted light by absorbing certain wavelengths and reflecting others.

Chlorophyll

The natural green pigment found in plants, algae, and cyanobacteria that absorbs sunlight to power photosynthesis.