Biology Chapter 7 Cellular Respiration

Once they have been processed through the citric acid cycle, the acetyl-CoA molecules from a single glucose molecule produce:

2 ATP, 6 NADH, 4 CO2, and 2 FADH2.

What is cellular respiration?

A series of chemical reactions that converts energy stored in fuel molecules into a chemical form that can be used by cells

In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water.

oxidized; reduced

oxidative phosphorylation

(Stage 4 of cellular respiration) - As electron carriers are reduced, ATP is generated - When electrons are transferred from electron carriers to the ETC - After the ETC, ADP + phosphate = ATP

Describe the process of the CAC

- The 2-carbon acetyl group of acetyl-CoA is transferred to a 4-carbon molecule of oxaloacetate to from the 6-carbon molecule citric acid - that citric acid is oxidized in a series of reactions -CO2 is released from pyruvate - 4 Redox Reactions produce 3 NADH and 1 FADH2 per cycle turn

Describe the process of pyruvate oxidation

- The pyruvate molecule is oxidized (loses electrons) to form CO2 - Electrons lost are donated to NAH+ to make NADH - The rest of the pyruvate is transferred to acetyl-coA

substrate-level phosphorylation

ADP + phosphate group = ATP

Glycolysis Phase 3: Payoff Phase

ATP and NADH are produced

During a long bout of sustained exercise, in which order will your body's energy stores/sources be used?

ATP stored in muscle, glycogen stored in muscle, glycogen stored in the liver, fatty acids

Where is the energy of the original glucose molecule stored at the end of the Citric Acid Cycle?

ATP, NADH, AND FADH2

3) Citric Acid Cycle

Acetyl-coA is broken down- 2 ATP, 6 NADH, and 2 FADH2, and CO2 are produced (occurs in the matrix)

Which molecules are reduced?

C6H12O6 (Glucose), NADH, FADH2 Reduced forms have more chemical energy than oxidized forms

Are carbon atoms oxidized or reduced during cellular respiration?

Carbon atoms are oxidized because they go from sharing bonds equally in C-C bonds to losing electrons in the Carbon-Oxygen bonds in CO2.

Glycolysis Phase 1: Preparatory Phase

Consumes 2 ATP, 2 phosphate groups are added to glucose, glucose is trapped in the cell

4. Oxidative Phosphorylation (Electron Transport Chain)

Electron carriers donate electrons to the ETC, the chain transfers electrons through proteins to a final electron acceptor and harnesses the energy of the electrons to produce ATP in the process

Lactic acid and ethanol fermentation differ in that:

Ethanol fermentation produces CO2 as a byproduct, but lactic acid fermentation does not.

Reaction for Glycolysis:

Glucose + 2NAD+ + 2ADP + 2Pi → 2 pyruvate + 2ATP + 2NADH + 2H+ + 2H2O

Where is the energy of the original glucose molecule stored at the end of glycolysis?

In pyruvate, ATP, and NADH

Which molecules are oxidized?

NAD+, FAD, CO2

Are oxygen atoms reduced or oxidized during cellular respiration?

Oxygen atoms are reduced because they partially gain electrons when water is formed

2) Pyruvate Oxidation

Pyruvate from cytoplasm passes to mitochondrial matrix, pyruvate is converted to acetyl-coA, CO2 and 2 NADH are produced (occurs in matrix)

Pyruvate oxidation

Pyruvate is transported to the mitochondrial matrix where it is converted to acetyl-CoA

Glycolysis Phase 2: Cleavage Phase

The 6-carbon sugar molecule is split into 2 3-carbon molecules

Why is a phosphate group added to glucose? (phosphorylation)

To trap glucose inside the cell

What is oxidized in the Citric Acid Cycle

acetyl-coA

Where is the energy of the original glucose molecule stored at the end of pyruvate oxidation?

acetyl-coA and NADH

An electron from NADH entering the electron transport chain would travel among components of the chain in what sequence?

complex I, coenzyme Q, complex III, cytochrome c, complex IV, oxygen

Oxygen is ________ in cellular respiration.

consumed

1) Glycolysis

the partial breakdown of glucose, 2 ATP and 2 NADH are released. (occurs in the cytoplasm)