Mitochondrial Cellular Respiration & Photosynthesis

Vocabulary flashcards covering mitochondrial cellular respiration stages, yields, chemical processes, and chlorophyll.

Oxidation

Loss of electrons.

Reduction

Gain of electrons.

Glycolysis 6-Carbon Breakdown

Glucose starts as a single 6-carbon molecule.

Glycolysis 3-Carbon Split

6-carbon glucose splits into two 3-carbon pyruvate molecules.

PFK (Phosphofructokinase)

Rate-limiting enzyme that determines the speed of glycolysis.

Respiration Oxidation Trend

Carbon molecules become increasingly oxidized as they progress from glucose to pyruvate to acetyl-CoA.

Glycolysis Oxygen Requirement

Stage I (Glycolysis) is anaerobic (occurs without oxygen).

Aerobic Stages

Stages II through V require oxygen.

Pyruvate Structure

Fructose without a phosphate group.

Stage I Location

Cytoplasm.

Stage I Gross Yield

4 ATP produced.

Stage I Cost

2 ATP consumed.

Stage I Net Yield

2 Pyruvate, 2 net ATP, and 2 NADH.

Stage II Location

Matrix of the mitochondrion.

Stage II Conversion

3-carbon pyruvate loses $CO_2$ and binds Coenzyme A to form 2-carbon Acetyl-CoA.

Stage II Yield

2 Acetyl-CoA and 2 NADH.

Citric Acid Cycle Reactant Entry

2-carbon Acetyl-CoA binds a 4-carbon acceptor molecule.

Citric Acid

6-carbon molecule formed at the start of the Citric Acid Cycle.

Citric Acid Cycle Repetitions

Cycle repeats 2 times per glucose molecule.

Stage III Yield

2 ATP, 6 NADH, and 2 $FADH_2$.

Stage III NADH Production

Yields the highest number of NADH across all respiration stages.

Respiratory $CO_2$ Origin

Byproduct produced during the Citric Acid Cycle and exhaled by the organism.

Respiratory $O_2$ Purpose

Inhaled oxygen acts as the final electron acceptor in Stage V.

Stage IV Proton Pumping

Energy from moving electrons pumps protons ($H^+$) against their concentration gradient.

Stage IV Proton Gradient

Protons are pumped from the matrix into the intermembrane space.

Stage IV Yield

No ATP or electron carrier yield.

Matrix pH Change

Matrix pH increases (becomes less acidic) as $H^+$ leaves.

Intermembrane Space pH Change

Intermembrane space pH decreases (becomes more acidic) as $H^+$ enters.

Proton Leakage / Uncoupling

$H^+$ flows back into the matrix without passing through ATP synthase, releasing energy as heat instead of ATP.

Terminal Electron Acceptor

Oxygen ($O_2$).

Water Formation in Respiration

Oxygen accepts 4 electrons and $4H^+$ from the matrix to form $2H_2O$.

Stage V Yield

Chemiosmosis produces the highest ATP (~32 ATP).

Total Respiration Net Yield

Approximately 38 maximum net ATP per glucose molecule.

ATP Hydrolysis

ATP splits into $ADP + P_i$, releasing energy through oxidation.

Chlorophyll

Plant pigment that absorbs light to excite electrons and reflects green light.