Biology 1010 Exam 3

Chapters 7-9

What organism does cellular respiration

All living organisms — plants animals fungi protists and bacteria

What are the phases of cellular respiration

Glycolysis, Citric acid cycle, Electron transport chain

Where does glycolysis take place

the cytoplasm, if oxygen is present pyruvate and NADH are moved into the mitochondria

Where does the Citric Acid Cycle Occur

In the mitochondrial matrix

Where does the Electron Transport Chain Occur

In cristae of mitochondria

What are the two electron carriers that participate in cellular respiration

Two main electron carriers are NAD+ and FAD+

NAD+

NAD+ (oxidized) accepts two electrons and one H+ to become NADH — reduced

FAD+

FAD+ (oxidized) accepts two electrons and two H+ to become FADH2 (reduced)

What occurs during the energy investment stage of glycolysis

Two ATP transfer phosphates to glucose

Activates them for next steps

What occurs during the energy havesting stage of glycolysis

Substrate level ATP synthesis produces four ATP

Net Gain of two ATP

TWO NADH made

Glycolysis benefits

Fast- glycolytic enxymess can be abundant and have quick turnover rates

Does not require oxygen

Oxygen availability determines what happens to pyruvate

With oxygen pryuvate enters mitochondria

Without oxygen pyruvate undergoes reduction

Anaerobic

without oxygen

Fermentation

anaerobic breakdown of glucose

Generates only two ATP total

Animal Cell Anaerobic Fermentation

Pyruvate reduced to lactate

Brief burst of energy for muscle cells

Recovery from oxygen deficit complete when enough oxygen is present to completely break down glucose

Lactate converted back to pyruvate or glucose

Microorganism Anaerobic Fermentation

bacteria use fermentation to produce: lactate or other organic acids, alcohol and carbon dioxide

Yeast - carbon dioxide makes bread rise, ethanol made into wine and beer

Cellular Respiration Preparatory Reactions

occurs in mitochondrial matrix

produces substrate that enters the citric acid cycle

2 carbon acetyl group attached to CoA to form acetyl-CoA

Preparatory Reactions - Producing a substate that enters the CAC

Pyruvate must be converter to acetyl-CoA

Pyruvate oxidized, CO2, molecule given off

DAD+ reduced to NADH

Preparatory Reactions - 2-Carbon acetyl group attached to CoA to form acetyl-CoA

Acetyl CoA transfer acetyl group to C4 molecule - produces citric acid (six carbons)

CoA returns to preparatory reaction for reuse

Citric Acid Cycle

Occurs in mitochondrial matrix

Acetyl group oxidized to carbon diozide

NAD+ → NADH and FAD → FADH2

Substrate level ATP synthesis produces ATP

Two cycles for each glucose molecule

Citric Acid Cycle inputs

2 acetyl-CoA

6 NAD+

2 FAD

2 ADP + 2 P

Cirtic Acid Cycle Outputs

4 CO2

6 NADH

2 FADH2

2 ATP

Electron Transport Chain

Located in cistae of mitochondria

Series of carriers pass electrons from one to the other