Cellular Respiration and Fermentation: In-Depth Notes

What is the definition of cellular respiration?

The process of breaking down sugar molecules to release energy in a controlled manner, generating ATP.

What is the main equation of cellular respiration?

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP + heat.

What is the relation between photosynthesis and cellular respiration?

Photosynthesis produces glucose and oxygen using light energy, while cellular respiration utilizes these products to release energy.

What are the main components of mitochondria?

Intermembrane space (high concentration of hydrogen ions), inner membrane (contains cristae, ATP synthase proteins, and electron transport chain components), and matrix (lower concentration of protons).

What is the structure of ATP?

Composed of a nitrogenous base (adenine), ribose sugar, and a chain of three phosphate groups.

What happens when ATP is hydrolyzed?

ATP + H2O → ADP + Pi (inorganic phosphate) + Energy; this reaction releases energy.

What is the function of NAD+ in cellular respiration?

NAD+ is an electron shuttle that carries electrons and hydrogen ions during redox reactions.

What is produced when NAD+ is reduced?

Reduction of NAD+ results in NADH, which carries the electrons to the electron transport chain.

Where does glycolysis occur?

Glycolysis occurs in the cytosol.

What are the products of glycolysis?

Glycolysis converts glucose to 2 pyruvate, generating 2 ATP and 2 NADH.

What occurs during the transition reactions?

Converts pyruvate to Acetyl CoA, producing NADH and releasing CO2.

What is generated during the Krebs cycle?

The Krebs Cycle generates 3 NADH, 1 FADH2, and 1 ATP per Acetyl CoA while releasing CO2.

What occurs at the Electron Transport Chain (ETC)?

NADH and FADH2 donate electrons, leading to the establishment of proton gradients.

What is the role of chemiosmosis in cellular respiration?

Protons flow back into the mitochondrial matrix through ATP synthase, powering ATP production.

What happens to pyruvate under anaerobic conditions?

Pyruvate undergoes fermentation to regenerate NAD+ and produce lactate or ethanol.

What is an example of fermentation in muscle cells?

In muscle cells, pyruvate is converted to lactate, utilizing electrons from NADH and regenerating NAD+.

What are the inputs and outputs of glycolysis?

Inputs: Glucose. Outputs: 2 Pyruvate, 2 ATP, 2 NADH.

What are the inputs and outputs of the transition reactions?

Inputs: 2 Pyruvate. Outputs: 2 Acetyl CoA, 2 NADH, CO2.

What are the inputs and outputs of the Krebs cycle?

Inputs: 2 Acetyl CoA. Outputs: 2 ATP, 6 NADH, 2 FADH2, 4 CO2.

What are the inputs and outputs of the electron transport chain?

Inputs: NADH, FADH2. Outputs: ATP (via oxidative phosphorylation).

What is the overall ATP yield in cellular respiration?

The ATP yield per glucose molecule varies at each stage and is efficient in utilizing energy for biological work.

What contributes to the high energy yield in cellular respiration?

High energy yield is due to coupled oxidation, electron transport, and chemiosmosis.

Which molecule is oxidized in cellular respiration?

Glucose is the molecule that is oxidized during cellular respiration.

Which molecule is reduced in cellular respiration?

Oxygen is the molecule that is reduced during cellular respiration, forming water.

What is an electron shuttle/carrier?

An electron shuttle or carrier is a molecule that transports electrons from one site to another within the cell, playing a crucial role in metabolic processes like cellular respiration. Examples include NADH and FADH2.

What are transition reactions also called?

Transition reactions are also called pyruvate oxidation.

Where do transition reactions take place?

Transition reactions take place in the mitochondria of eukaryotic cells.

Where does the Krebs cycle occur?

The Krebs cycle occurs in the mitochondrial matrix.

Where does chemiosmosis occur?

Chemiosmosis occurs across the inner mitochondrial membrane.

What is the function of the electron transport chain?

The electron transport chain functions to transfer electrons through a series of protein complexes, leading to the pumping of protons and the production of ATP through chemiosmosis.

What are the primary molecules that enter the electron transport chain?

NADH and FADH2 are the primary molecules that enter the electron transport chain.

What is substrate-level phosphorylation?

The direct transfer of a phosphate group from a substrate molecule to ADP to form ATP, occurring during specific steps of glycolysis and the Krebs cycle.

What is another name for the Krebs cycle?

The Krebs cycle is also known as the Citric Acid Cycle.