Cell respiration

State the full name of ATP

Adenosine Triphosphate.

List three ways that ATP is suitable as an energy source

Cannot pass through cell membranes—each cell must make its own ATP. It is hydrophilic, allowing reactions in the cytoplasm. It releases energy in small, manageable quantities by hydrolysis into ADP + Pi.

List the three main uses for ATP and give examples for each

Transport—active transport of ions across membranes. Synthesis—DNA replication, protein synthesis. Movement—muscle contraction, chromosome movement during mitosis.

Explain the importance of the hydrolysis of ATP and explain how it works

Hydrolysis of ATP releases energy by breaking the bond between the second and third phosphate, which is used for cellular processes.

Explain why it takes energy to produce ATP from ADP + Pi

Energy from cellular respiration is used to reform ATP from ADP + Pi, making ATP a renewable energy carrier.

State the principal types of carbon compounds that can be used for producing ATP

Glucose, fatty acids, and other carbohydrates like fructose, sucrose, lactose, and galactose.

Name other molecules that can be used to create ATP

Proteins, which can be broken down into intermediates for respiration.

Is O₂ needed as e⁻ acceptor for both types of respiration?

Yes for aerobic, no for anaerobic.

Input for both types of respirations

Aerobic: Glucose + O₂. Anaerobic: Glucose.

Waste for both types of respiration

Aerobic: CO₂ + H₂O. Anaerobic: Lactic Acid.

ATP yield per glucose for both types of respiration

Aerobic: ~36-38 ATP. Anaerobic: ~2 ATP.

Location for both types of respiration

Aerobic: Mitochondria. Anaerobic: Cytoplasm.

Uses of both respirations

Aerobic: Long-term energy. Anaerobic: Short bursts of energy.

Word Equation for both types of respiration

Aerobic: Glucose + O₂ → CO₂ + H₂O + ATP. Anaerobic: Glucose → Lactic Acid + ATP.

Explain oxygen debt

The extra oxygen required to metabolize lactic acid and restore ATP levels after anaerobic respiration.

What other DV could we have measured?

ATP concentration or alcohol production.

What other IVs could we have measured?

Temperature, pH, type of sugar used.

Define oxidation

Loss of electrons or hydrogen.

Define reduction

Gain of electrons or hydrogen.

Distinguish oxidation from reduction

Oxidized molecules lose energy, reduced molecules gain energy.

What happens to the charge of an atom or molecule that is oxidized?

Becomes more positive.

What happens to the charge of an atom or molecule that is reduced?

Becomes more negative.

Define an electron carrier and use an analogy to explain

A molecule that transports electrons during cellular respiration.

State the shorthand name of the electron carrier used in cell respiration

NAD⁺.

Write the equation for the reduction of NAD⁺

NAD⁺ + 2H → NADH + H⁺.

State the role of electron carriers in cell respiration

Transport electrons to the electron transport chain (ETC) to drive ATP production.

Define phosphorylation and explain its role in the cell

The addition of a phosphate group to a molecule, making it more reactive.

State the input and output molecules of glycolysis

Input: Glucose, 2 ATP, 2 NAD⁺. Output: 2 Pyruvate, 4 ATP (net gain = 2), 2 NADH.

Identify and explain the four steps of glycolysis

Phosphorylation—ATP adds phosphate to glucose. Lysis—glucose-6-phosphate splits into two triose phosphates. Oxidation—NAD⁺ is reduced to NADH. ATP Formation—ATP is produced by substrate-level phosphorylation.

Define lactic acid fermentation including its reactants and products

A process that converts pyruvate into lactic acid to regenerate NAD⁺. Reactants: Pyruvate, NADH. Products: Lactic Acid, NAD⁺.

State in which organism lactic acid fermentation occurs in and where in the cells of the organism

Occurs in humans, in muscle cells.

State the purpose of lactic acid fermentation

To regenerate NAD⁺ for glycolysis to continue.

Define alcoholic fermentation including its reactants and products

A process in yeast that converts pyruvate into ethanol and CO₂ to regenerate NAD⁺. Reactants: Pyruvate, NADH. Products: Ethanol, CO₂, NAD⁺.

State in which organism alcoholic fermentation occurs and where in the cells of the organism

Yeast, in the cytoplasm.

State the purpose of alcoholic fermentation

To regenerate NAD⁺ for glycolysis to continue.

Define the link reaction, its reactants and products

A process that converts pyruvate into Acetyl-CoA for the Krebs cycle. Reactants: Pyruvate, NAD⁺, CoA. Products: Acetyl-CoA, CO₂, NADH.

Where does the link reaction occur?

Mitochondrial matrix.

How are products delivered there for link reaction?

Pyruvate is transported via facilitated diffusion.

State and explain the three steps of the link reaction

Decarboxylation—CO₂ is removed from pyruvate. Oxidation—NAD⁺ is reduced to NADH. Formation of Acetyl-CoA—CoA binds with the acetyl group.

Explain how simple sugars are used in cell respiration

Directly enter glycolysis for ATP production.

Explain how fats are used in cell respiration

Broken into glycerol (used in glycolysis) and fatty acids (converted to Acetyl-CoA for Krebs cycle).

Explain the differences between the use of carbohydrates and fats in cellular respiration

Carbohydrates can be used in glycolysis and anaerobic respiration, while fats must be hydrolyzed into smaller molecules before entering respiration. Fats produce more ATP per gram than carbohydrates.