Photosynthesis and Cellular Respiration Lecture Notes

A set of vocabulary flashcards covering the processes of photosynthesis and cellular respiration based on lecture notes.

Photosynthesis

A process that involves converting light energy to chemical energy.

Chloroplasts

The organelles where photosynthesis takes place, containing chlorophyll.

Chlorophyll

A pigment that absorbs light energy from the sun, specifically violet, blue, and red wavelengths, while reflecting green.

Chlorophyll A

The dominant pigment found in all plants, often working with accessory pigments.

Absorption spectrum

A graph showing the percentage of wavelengths of light that a specific pigment has absorbed.

Action spectrum

A graph showing the overall effectiveness of different wavelengths of light for promoting photosynthesis.

Chromatography

A technique where the tip of filter paper is placed in a solvent to separate pigments based on their size (smaller travel further) and solubility (more soluble travel further).

Oxidization

The loss of electrons during a chemical reaction.

Reduction

The gain of electrons during a chemical reaction.

Light Dependent reactions

Reactions occurring in the thylakoid where energy from the sun is converted to $ATP$ and $NADPH$.

Photosystems

Clusters of chlorophyll on the surface of the thylakoid membrane that absorb light energy.

Photosystem 1 (PS 1)

A system where photons are absorbed by chlorophyll pigments to reduce $NADP$ into $NADPH$ via the reaction: $NADP + e^- + H^+ ightarrow NADPH$.

Photosystem 2 (PS 2)

A system on the thylakoid membrane where light excites electrons, which are then passed through an electron transport chain ($ETC$) to $PS 1$, using energy to move $H^+$ from the stroma into the thylakoid.

Photolysis of water

The process where light splits water to replace electrons in $PS 2$, following the reaction: H_2O ightarrow 2H + 2e^- + rac{1}{2} O_2.

Chemiosmosis

The movement of hydrogen ions down a concentration gradient through the $ATP$ synthase channel to drive the production of $ATP$ ($ADP + P ightarrow ATP$).

Light-independent reactions

Also known as the Calvin Cycle, these occur in the stroma and use $ATP$ and $NADPH$ to produce carbohydrates.

Carbon fixation

The first stage of the Calvin Cycle where a carbon atom from $CO_2$ bonds to $RuBP$ to produce an unstable $6C$ molecule.

Triose phosphate

A $3C$ compound produced when the unstable $6C$ molecule splits during the reduction phase of the Calvin Cycle.

Regeneration of RuBP

The process where $5$ out of every $6$ molecules of $3C$ compounds are converted back into $RuBP$ using $ATP$ to continue the Calvin Cycle.

Overall reaction of photosynthesis

The chemical equation: $6 CO_2 + 6 H_2O ightarrow C_6H_{12}O_6 + 6 O_2$.

Respiration

The process that releases potential energy, such as $ATP$, from organic compounds like glucose.

Biological work

Activities carried out by cells using $ATP$, including movement, active transport, secretion, cell division, and nerve impulse transmission.

Aerobic cellular respiration

The breakdown of pyruvate in the mitochondria with oxygen to produce $CO_2$, $H_2O$, and $36 ext{ ATP}$. Equation: $C_6H_{12}O_6 ightarrow 6CO_2 + 6H_2O + 36 ext{ ATP}$.

Glycolysis

The initial stage of respiration occurring in the cytoplasm where glucose is split into $2$ pyruvate molecules, yielding a net of $2 ext{ ATP}$ without the need for oxygen.

Link reaction

Process where pyruvate is decarboxylated to form a $2C$ compound called acetyl $CoA$, linking glycolysis to the Krebs cycle.

Krebs Cycle

A series of reactions in the mitochondrial matrix where acetyl $CoA$ is processed through decarboxylation and the reduction of $NAD$ and $FAD$, producing a net of $2 ext{ ATP}$ per glucose.

Electron Transport Chain (Respiration)

A series of proteins in the inner mitochondrial membrane that pass electrons to drive proton pumps, creating a gradient where oxygen acts as the final electron acceptor.

Anaerobic respiration

The conversion of pyruvate in the cytoplasm into lactate (animals) or ethanol and $CO_2$ (yeast/plants) without further yield of $ATP$ when oxygen is absent.