ap bio photosynthesis and cellular respiration

Photosynthesis

The process in which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose (C6H12O6).

Chlorophyll

The main pigment in plants that absorbs light energy (mostly blue and red wavelengths) for photosynthesis.

Carotenoids

Accessory pigments that absorb additional light wavelengths (like orange and yellow) and protect chlorophyll from damage.

Thylakoids

Flattened sacs inside chloroplasts where the light reactions of photosynthesis occur.

Stroma

The fluid-filled space around the thylakoids in the chloroplast where the Calvin cycle takes place.

Mesophyll

Leaf tissue cells rich in chloroplasts where most photosynthesis occurs.

Light Reactions

The first stage of photosynthesis; converts solar energy into chemical energy (ATP and NADPH) and releases O2.

Calvin Cycle

The second stage of photosynthesis; uses ATP and NADPH to fix CO2 into glucose.

Rubisco

The enzyme that catalyzes CO2 fixation in the Calvin cycle; can also bind O2 in photorespiration.

Photorespiration

A wasteful process when rubisco binds O2 instead of CO2, reducing photosynthetic efficiency.

NADP+

An electron carrier molecule in photosynthesis that becomes NADPH when reduced.

Water (H2O)

Splits during the light reactions to provide electrons and protons, releasing O2 as a byproduct.

CO2 (Carbon Dioxide)

Used in the Calvin cycle to form glucose.

O2 (Oxygen)

Produced during the light reactions of photosynthesis; used in cellular respiration.

C6H12O6 (Glucose)

The main fuel molecule broken down to produce ATP in cellular respiration.

ATP (Adenosine Triphosphate)

The energy currency of the cell; provides energy for most cellular processes.

Glycolysis

The first step of cellular respiration; breaks glucose into pyruvate, producing a small amount of ATP and NADH.

Acetyl CoA

The molecule formed from pyruvate before entering the citric acid cycle.

Citric Acid Cycle (Krebs Cycle)

Breaks down acetyl CoA to produce CO2, ATP, NADH, and FADH2.

Electron Transport Chain (ETC)

A series of proteins in the mitochondrial membrane that transfer electrons, releasing energy to form ATP.

ATP Synthase

Enzyme that uses the flow of H+ ions through the membrane to generate ATP from ADP and phosphate.

Substrate-Level Phosphorylation

ATP formation by directly transferring a phosphate group to ADP from an intermediate substrate.

Anaerobic Respiration

Energy production without oxygen; uses other electron acceptors instead of O2.

Alcohol Fermentation

Anaerobic process where pyruvate is converted into ethanol and CO2, regenerating NAD+.

Lactic Acid Fermentation

Anaerobic process in which pyruvate is converted into lactic acid, regenerating NAD+.