Cell Energy 2

Glycolysis

A step of cellular respiration in the cytoplasm that splits a six-carbon glucose molecule into two three-carbon pyruvate molecules, producing ATP and electron carriers.

Pyruvate oxidation

A step of cellular respiration where a three-carbon molecule is converted into a two-carbon unit attached to a carrier, releasing carbon dioxide and electron carriers.

Citric Acid cycle

A step of cellular respiration in the mitochondria matrix that processes two-carbon Acetyl CoA molecules to release carbon dioxide while producing energy carriers and ATP.

Oxidative phosphorylation

A step of cellular respiration on the inner mitochondrial membrane where energy from electrons moving through protein complexes is used to create a proton gradient that drives the production of ATP and water.

Oxidation

The loss of electrons from a substance during a chemical reaction.

Reduction

The gain of electrons by a substance during a chemical reaction.

Endergonic

A type of reaction that requires a net input of energy to occur.

Exergonic

A type of reaction that releases a net amount of energy to the surroundings.

Aerobic respiration vs. Anaerobic respiration (Oxygen use)

Aerobic cellular respiration uses oxygen as the final electron acceptor, whereas anaerobic cellular respiration occurs without oxygen and uses alternative pathways or electron acceptors.

Anaerobic respiration vs. Aerobic respiration (ATP yield)

Anaerobic cellular respiration occurs without oxygen and produces less ATP, whereas aerobic cellular respiration uses oxygen to fully break down food molecules into carbon dioxide and water while producing ATP.

Forming ATP from ADP and inorganic phosphate

True (it is an endergonic process that requires an input of energy).

Converting ADP to ATP is exergonic

False, the hydrolysis of ATP into ADP is exergonic (converting ADP to ATP is endergonic).

The conversion of NADH to NAD+

True (this oxidation process is exergonic and releases energy).

The conversion of NAD+ to NADH is exergonic

False, the reduction of NAD+ to NADH requires a net input of energy (it is an endergonic process). This energy comes from the oxidation of food molecules during cellular respiration.

Most ATP in aerobic respiration is produced during oxidative phosphorylation

True.

Glycolysis produces more ATP than the citric acid cycle and oxidative phosphorylation

False, only 2 ATP out of the ~32 ATP made per glucose is produced in glycolysis.

Oxygen is required for oxidative phosphorylation because it acts as the final electron acceptor

True.

Oxygen is required for glycolysis to occur

False, glycolysis occurs in the cells of all living organisms regardless if oxygen is present in their cells.

Lactic acid fermentation and ethanol fermentation both produce NAD+ so that glycolysis can continue in anaerobic conditions

True.

Lactic acid fermentation and ethanol fermentation both produce NADH so that glycolysis can continue in anaerobic conditions

False, fermentation produces NAD+, which is a reactant of glycolysis. Without fermentation the cell would run out of NAD+ in anaerobic conditions and would die. During fermentation, pyruvate is also converted into lactic acid or into ethanol and carbon dioxide.