Photosynthesis and Cellular Respiration (Science Grade 9 ADM Module 5)

Vocabulary flashcards covering key terms and definitions from the Photosynthesis and Cellular Respiration module.

Photosynthesis

The process by which plants and other autotrophs convert carbon dioxide and water into glucose (food) using light energy, releasing oxygen; occurs in chloroplasts.

Cellular respiration

The process by which cells convert glucose and oxygen into carbon dioxide, water, and ATP (energy); occurs in mitochondria.

Autotroph

An organism that can synthesize its own food from inorganic sources, e.g., plants; uses photosynthesis.

Heterotroph

An organism that cannot synthesize its own food and relies on consuming other organisms for energy.

Chloroplast

Plant cell organelle where photosynthesis occurs; contains chlorophyll, thylakoids, grana, and stroma.

Mitochondrion

Cell organelle where cellular respiration occurs; produces ATP.

Chlorophyll

Green pigment in chloroplasts that captures light energy for photosynthesis.

Thylakoid

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

Granum

A stack of thylakoids within a chloroplast.

Stroma

Fluid surrounding the thylakoids in a chloroplast; site of the Calvin Cycle.

Light-dependent reactions

First stage of photosynthesis that uses light to generate ATP and NADPH and releases oxygen; occurs in the thylakoid membrane.

Calvin Cycle (Light-independent reactions)

Second stage of photosynthesis; uses CO2 and the energy carriers ATP and NADPH to synthesize glucose in the stroma.

NADPH

Reduced electron-carrier produced during the light reactions used in the Calvin Cycle.

ATP

Adenosine triphosphate; energy currency of the cell produced during photosynthesis and respiration.

NADH

Reduced form of NAD+, carries electrons to the electron transport chain during respiration.

FADH2

Reduced form of FAD; electron carrier in the electron transport chain contributing to ATP production.

Glycolysis

First stage of cellular respiration; occurs in cytoplasm; glucose split into two pyruvate, yielding a net 2 ATP and 2 NADH.

Pyruvate oxidation

Process that converts pyruvate to acetyl-CoA, releasing CO2 and producing NADH, occurs in mitochondria.

Krebs Cycle

Oxidizes acetyl-CoA to CO2, generating NADH, FADH2, and ATP; part of cellular respiration.

Electron Transport Chain (ETC)

Series of proteins in the inner mitochondrial membrane that transfer electrons to oxygen, producing ATP via oxidative phosphorylation.

Aerobic respiration

Cellular respiration that requires oxygen; yields a large amount of ATP (about 38 per glucose in some teaching resources).

Anaerobic respiration

Respiration without oxygen; yields little ATP (about 2 net ATP per glucose) and produces fermentation products like ethanol or lactic acid.

Acetyl-CoA

Two-carbon molecule formed from pyruvate oxidation; enters the Krebs Cycle.

Glucose

A simple sugar that fuels cellular respiration and is produced by photosynthesis.

Oxygen

Gas consumed in cellular respiration and produced in photosynthesis; final electron acceptor in the ETC.

Carbon dioxide

Gas produced in respiration and used in photosynthesis; reactant in the Calvin Cycle.

Water

Product of cellular respiration and a reactant in photosynthesis.

Sunlight

Energy from the sun that drives photosynthesis.

Stomata

Leaf pores that enable gas exchange (CO2 in, O2 out, water vapor).