Photosynthesis and Cellular Respiration

Vocabulary practice flashcards covering the key terms, structures, processes, inputs, and outputs of photosynthesis and cellular respiration.

ATP (Adenosine Triphosphate)

The cell's main energy molecule that stores energy between its second and third phosphate groups, releasing energy when converted: $\text{ATP} \rightarrow \text{ADP} + \text{P} + \text{energy}$.

Autotrophs

Producers that make their own energy by utilizing sunlight through photosynthesis.

Heterotrophs

Consumers that obtain energy by consuming other organisms and breaking down glucose and carbohydrates.

Chloroplast

The plant organelle where photosynthesis takes place.

Thylakoid

A disc-shaped structure inside the chloroplast that contains chlorophyll and serves as the location for the light-dependent reactions.

Granum

A stack of thylakoids located inside a chloroplast.

Stroma

The fluid surrounding the thylakoids within the chloroplast where the Calvin cycle (light-independent reactions) occurs.

Chlorophyll

A green light-absorbing pigment that absorbs red and blue-violet light while reflecting green light.

Light-Dependent Reactions

The initial stage of photosynthesis occurring in the thylakoid membrane that takes in sunlight and water to generate ATP, NADPH, and oxygen.

Photosystem

A cluster of chlorophyll and proteins located in the thylakoid membrane that absorbs light and energizes electrons.

Photosystem II

The photosystem that begins the light-dependent reactions by splitting water into electrons, $H^+$ ions, and oxygen to replace lost electrons.

Photosystem I

The photosystem that re-energizes electrons as they travel along the photosynthetic electron transport chain.

ATP Synthase

A membrane protein complex through which $H^+$ ions pass to produce ATP from ADP.

Calvin Cycle

The light-independent stage of photosynthesis occurring in the stroma that uses $CO_2$, ATP, and NADPH to synthesize sugar.

C4 Plants

Plants adapted to high temperatures and intense light that require extra ATP to fix carbon, including corn, sugarcane, and sorghum.

Glycolysis

The anaerobic first stage of cellular respiration located in the cytoplasm, breaking down one glucose ($6\text{C}$) into two pyruvate ($3\text{C}$ each), using $2\text{ ATP}$ and producing $4\text{ ATP}$ (net $2\text{ ATP}$) and $2\text{ NADH}$.

Krebs Cycle

The second stage of cellular respiration (citric acid cycle) located in the mitochondrial matrix, where pyruvate forms Acetyl-CoA and releases carbon to produce $CO_2$, ATP, and electron carriers.

Electron Transport Chain (Cellular Respiration)

An aerobic stage located in the inner mitochondrial membrane that uses high-energy electrons from NADH or $FADH_2$ and oxygen to pump $H^+$ ions, synthesizing ATP and forming water.

Cellular Respiration ATP Totals

The overall class yield of $36\text{ ATP}$ per glucose molecule, resulting from glycolysis ($2\text{ ATP}$), the Krebs cycle, and the electron transport chain ($32\text{ ATP}$).