Cellular Respiration and Photosynthesis

Vocabulary flashcards covering cellular respiration, fermentation, and the light-dependent and light-independent reactions of photosynthesis.

Glycolysis

A process that nets two ATP and produces two pyruvate.

Substrate level phosphatization

The generation of ATP via the direct transfer of a phosphate from another molecule.

Hexokinase

The enzyme for the first committed step of glycolysis that transforms glucose to glucose six phosphate while consuming one ATP; this irreversible step prevents glucose from leaving the cell.

Phosphofructokinase

An enzyme that adds a second phosphate to the molecule, committing it to the glycolysis pathway.

Aerobic respiration reaction

$$C_6H_{12}O_6 + 6O_2 <br /> ightarrow 6CO_2 + 6H_2O + ext{ATP}$$

Pyruvate dehydrogenase complex

A complex located in the mitochondrial matrix that transforms pyruvate into acetyl CoA.

Citric acid cycle / Krebs cycle

A cycle in which pyruvate is transformed into acetyl CoA, which is used to regenerate oxaloacetate and produces $CO_2$, ATP, $FADH_2$, and NADH.

Electron transport chain (ETC)

A series of carrier proteins in the inner mitochondrial membrane that passes electrons to generate an $H^+$ gradient, providing energy for ATP synthase.

Final electron acceptor (Aerobic)

Oxygen, which combines with $H^+$ to form $H_2O$ at the end of the ETC.

Anaerobic respiration

A process that regenerates oxidized $NAD^+$ from NADH so that glycolysis can continue to run without oxygen.

Alcohol fermentation

A process occurring in plants, fungi, and yeast where pyruvate is converted into acetyl acetylaldehyde and $CO_2$, followed by conversion to ethanol to regenerate $NAD^+$.

Acetyl acetylaldehyde

The final electron acceptor in alcohol fermentation.

Lactic acid fermentation

A process in human muscle cells and microorganisms that converts pyruvate to lactate, regenerating $NAD^+$ from NADH.

Chlorophyll a molecules

$P680$ and $P700$; these contain a porphyrin ring with an $Mg^{2+}$ atom inside.

Granum

Stacks of thylakoids found within the chloroplast.

Thylakoid lumen

The location of photolysis and where $H^+$ ions accumulate due to the electron transport chain.

Stroma

The location where the Calvin cycle takes place within the chloroplast.

Stromalomalae

The specific location where cyclic phosphorylation occurs.

Cyclic phosphorylization

A path where two electrons from PSI go back through the first ETC to generate one ATP before being recycled into PSI.

Noncyclic phosphorylization

A path where two electrons move through an ETC to combine with $NAD^+$ and $H^+$ to form NADPH for use in the carbon cycle.

Carboxylation (Calvin Cycle)

The first step where $6CO_2 + 6RuBP$ produces $12PGA$, catalyzed by the enzyme RuBisCO.

Reduction (Calvin Cycle)

The step where $12ATP + 12NADH$ converts $12PGA$ into $12G3P$ (or $12GAL$).

Regeneration (Calvin Cycle)

The process where $6ATP$ is used to convert $10G3P$ back into $6RuBP$.

Action spectrum

The range of light effectiveness for photosynthesis; chloroplasts absorb red and blue light effectively, while green light is reflected.

Photolysis

The process where $H_2O$ splits into $2H^+$, two electrons, and $rac{1}{2}O_2$, occurring in PSII to replenish lost electrons.

C4 photosynthesis

An alternative pathway that alters the location of photosynthesis by moving $CO_2$ to bundle sheath cells to minimize photorespiration and water loss.

CAM photosynthesis

An alternative pathway that alters the timing of photosynthesis by fixing $CO_2$ at night to minimize photorespiration and water loss.