AP BIO - Unit 3

absorption spectrum

A graph that shows the wavelengths of light absorbed by a substance, indicating the specific pigments or molecules that absorb different wavelengths, commonly used to analyze chlorophyll and other pigments in biological studies.

chloroplast

Organelles in plant cells that conduct photosynthesis, containing chlorophyll and absorbing light energy.

NAD/NADH

A coenzyme that plays a crucial role in the electron transport chain and cellular respiration by accepting and donating electrons.

acetyl coA

A central metabolite in cellular respiration, formed from pyruvate and used in the Krebs cycle to produce energy.

citric acid/Krebs cycle

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins.

NADP/NADH

a coenzyme involved in oxidation-reduction reactions, serving as an electron carrier in photosynthesis and cellular respiration.

anabolism

The metabolic process that builds larger molecules from smaller units, requiring energy input. Anabolism is essential for growth and repair in organisms.

electron transport chain

A series of protein complexes and other molecules that transfer electrons from electron donors to electron acceptors via redox reactions, ultimately leading to ATP synthesis.

oxidative phosphorylation

anaerobic metabolism

A metabolic process that occurs without oxygen, allowing organisms to produce energy in low-oxygen environments.

FAD/FADH2

A redox cofactor involved in cellular respiration that serves as an electron carrier, converting to FADH2 during the Krebs cycle.

photolysis

splitting of water into electrons, H+ and oxygen

ATP

Adenosine triphosphate, a high-energy molecule that stores and provides energy for cellular activities.

feedback inhibition

A regulatory mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway, preventing overproduction of the product.

photosynthesis

The process by which green plants, algae, and some bacteria convert light energy into chemical energy, producing glucose and oxygen from carbon dioxide and water.

ATP synthase

An enzyme that helps produce ATP from ADP and inorganic phosphate during oxidative phosphorylation in cellular respiration.

fermentation

A metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen.

photosystem I

A complex of proteins and pigments in plants that plays a crucial role in the light-dependent reactions of photosynthesis, primarily involved in the conversion of light energy into chemical energy.

autotroph

Organisms that produce their own food using light or chemical energy, such as plants and certain bacteria.

glycolysis

The process of breaking down glucose to produce energy, resulting in the formation of pyruvate, ATP, and NADH.

photosystem II

A protein and pigment complex in plants and cyanobacteria that plays a critical role in photosynthesis, specifically in the light-dependent reactions. It absorbs light energy to produce ATP and NADPH.

Calvin cycle

A series of biochemical reactions that take place in the chloroplasts of photosynthetic organisms, converting carbon dioxide into glucose using ATP and NADPH.

light dependent reactions

The light dependent reactions are the first stage of photosynthesis, occurring in the thylakoid membranes of chloroplasts, where sunlight is used to convert water and carbon dioxide into ATP and NADPH.

pyruvate

The end product of glycolysis, pyruvate is a three-carbon molecule that enters the Krebs cycle for further energy production.

cellular respiration

A metabolic process that converts glucose and oxygen into ATP, carbon dioxide, and water through glycolysis, the citric acid cycle, and oxidative phosphorylation.

light independent reactions

Reactions in photosynthesis that do not directly require light. The primary example is the Calvin cycle, where carbon dioxide is converted into glucose.These reactions occur in the stroma of chloroplasts and utilize ATP and NADPH produced during the light-dependent reactions.

stroma

The fluid-filled space in chloroplasts where light-independent reactions, also known as the Calvin cycle, take place.

stroma

chemiosmosis

is the fluid-filled space in chloroplasts where the Calvin cycle takes place.

metabolic pathway

a series of chemical reactions in a cell that convert a substrate into a product.

substrate-level phosphorylation

A metabolic process that generates ATP by directly transferring a phosphate group from a substrate molecule to ADP, rather than through an electron transport chain.

chlorophyll

A green pigment found in plants, algae, and cyanobacteria that is crucial for photosynthesis, allowing organisms to absorb light energy, primarily from the sun.

mitochondrion

An organelle found in eukaryotic cells that is the site of aerobic respiration, generating ATP through oxidative phosphorylation.

thylakoid membrane

The site of light-dependent reactions in photosynthesis, where chlorophyll is embedded and ATP is produced.