1. Introduction to Human Anatomy & Physiology Acids, Bases & Chemicals
Pima Medical Institute
Cellular Respiration
Introduction to Human Anatomy & Physiology
Acids, Bases & Chemicals
Cellular Respiration
Pima Medical Institute Online Education
David Shier, Jackie Butler, Ricki Lewis, Hole’s Essentials of Human Anatomy & Physiology, 10th Ed. CopyrightThe McGraw-Hill Companies, Inc. Created by Dr. Melissa Eisenhauer, Trevecca Nazarene University

2. Energy is mostly lost as heat and light
Oxidation
Chemical energy is held in the bonds between the atoms of molecules and is released when these bonds are broken
Chemical energy is held in the bonds between the atoms of molecules and is released when these bonds are broken, as in burning (or oxidation). Simply "burning" a substance, as occurs outside the cell, requires a tremendous amount of activation energy. The energy released is mostly lost as heat and light.
Energy is mostly lost as heat and light
“Burning” a substance requires a tremendous amount of EA

3. Cellular Respiration CELLULAR RESPIRATION ATP
enzyme
Enzymes reduce the EA required for oxidation in cellular respiration
CELLULAR RESPIRATION
Glycolysis
Occurs in the cytosol
Does not require oxygen
ATP
The total yield of ATP molecules per glucose molecule is 36-38
Citric Acid Cycle
ATP
Occurs in the mitochondrion
Requires oxygen
Inside the cells, oxidation is controlled by enzymes which reduce the activation energy required for the oxidation that occurs in the reactions of cellular respiration.
Cellular respiration occurs in three distinct, yet interconnected, series of reactions: glycolysis, the citric acid cycle, and the electron transport chain. Glycolysis occurs in the cytosol and does not require oxygen. The citric acid cycle and the electron transport chain occur in the mitochondrion and do require oxygen.
Although most of the energy is lost as heat, almost half of the energy is captured in the form of high-energy electrons that the cell can store through the synthesis of ATP (adenosine triphosphate). Note that 2 ATP are generated by glycolysis, 2 result directly form the citric acid cycle, and are generated by the electron transport chain. Thus the total yield of ATP molecules per glucose molecule is 36-38, depending on the type of cell.
Electron Transport Chain
ATP

4. ATP Molecule
Adenosine triphosphate (ATP) is the primary energy storage molecule for the cell
The cell uses ATP for active transport and the
synthesis of various compounds
Chain of 3 phosphates
Energy can be used for:
Muscle contractions
Active transport
Chemical compound manufacture
ATP is the primary energy storage molecule for the cell, much like a rechargeable battery. The energy from ATP can be used for a variety of functions such as: muscle contractions, active transport, or chemical compound manufacture.
Each ATP molecule includes a chain of three chemical groups called phosphates. As energy is released during cellular respiration, some of it is captured in the bond of the end phosphate. When energy is required for a metabolic reaction, this terminal phosphate bond breaks, releasing the stored energy.
Energy from cellular respiration is stored in this phosphate
Stored energy is used for metabolic reaction

5. ADENOSINE DIPHOSPHATE ADP is recharged with another terminal phosphate
ADP Molecule
After the ATP molecule releases its terminal phosphate, it becomes ADP (adenosine diphosphate). The resulting ADP molecule returns to be "recharged" by gaining another terminal phosphate. Thus, ATP and ADP molecules shuttle phosphates back and forth between the energy-releasing reactions of cellular respiration and the energy-utilizing reactions of the cell.
ADENOSINE DIPHOSPHATE
ADP is recharged with another terminal phosphate
ATP and ADP shuttle phosphates back and forth to constantly release and utilize energy

6. Anaerobic Respiration
cytosol
Glycolysis
Anaerobic phase
(does not require oxygen)
A 6-C glucose is split into
two 3-C molecules of pyruvate
Citric Acid Cycle
Cellular respiration begins with glycolysis, which means “the breaking of glucose.” Glycolysis occurs in the cytosol and because it does not require oxygen, it is sometimes referred to as the anaerobic phase of cellular respiration.
The first part of cellular respiration is the splitting of 6-C glucose that occurs through a series of enzyme-catalyzed steps called glycolysis. The result is two 3-C molecules of pyruvate. Energy from ATP is used to start the process but there is a net gain of energy as a result.
Electron Transport Chain
ATP energy is used to start the process
and a net gain of energy results
mitochondrion

7. Electron Transport Chain
Aerobic Respiration
Glycolysis
Electron Transport Chain
Citric Acid Cycle
cytosol
mitochondrion
1 glucose molecule
ATP
38 ATP molecules
heat
Since the citric acid cycle and electron transport chain require oxygen, they are forms of aerobic respiration. If oxygen is present in sufficient quantity, the pyruvic acid generated by glycolysis can enter the more energy efficient pathways of aerobic respiration in the mitochondria.
For each glucose molecule that is decomposed completely, up to 38 molecules of ATP can be produced. Two of the ATP molecules are the result of glycolysis, and the rest form during the aerobic phase. About half the energy release goes to ATP synthesis, while the rest ends up as heat.
In addition to releasing energy, the complete oxidation of glucose produces carbon dioxide and water. The carbon dioxide is eventually exhaled, and the water becomes part of the internal environment.
Aerobic phase
(Requires oxygen)
H2O
CO2
Energy

8. 3 Stages of Cellular Respiration
cytosol
Glycolysis
Krebs Cycle
Anaerobic (no oxygen)
Acetyl-CoA
Infusion of water
Conversion of molecules
Release of CO2
ATP
Aerobic
Glycolysis
occurs in the cytosol and
is a 10-step anaerobic process
I’m going to make some ATP!
Krebs Cycle
Aerobic
Cellular respiration has three main stages: glycolysis, the Krebs cycle (also known as the citric acid cycle), and the electron transport chain. Glycolysis is anaerobic—it doesn’t require oxygen. The Krebs cycle and the electron transport chain are aerobic processes meaning they DO require oxygen.
Recall that glycolysis occurs in the cytosol and is an 10-step anaerobic process.
The next stage of cellular respiration, the Krebs cycle (or citric acid cycle), occurs in the mitochondria. In an 8-step process, each Acetyl-CoA molecule goes through many changes that include the infusion of water, the conversion of many molecules, and the release of carbon dioxide. The final product is one molecule of ATP per molecule of acetyl-CoA converted through the Krebs Cycle. The Krebs cycle is a big part of how living things convert food into energy. Most living things generate ATP from the proteins that they consume and it is ATP that gives them energy.
Electron Transport Chain
Aerobic
mitochondrion

9. 3 Stages of Cellular Respiration
cytosol
Glycolysis
Electron Transport Chain
ATP
Release of H atoms
More ATP
Krebs Cycle
The final stage of cellular respiration is the Electron Transport Chain or System. Recall that it also requires aerobic respiration. This final stage occurs in the inner wall of the mitochondria. From ATP produced by the Krebs cycle, hydrogen atoms are released and used in the Electron Transport Chain to produce more ATP.
Electron Transport Chain
Aerobic
mitochondrion

10. Practical Application
Air
O2 transported to cells
CO2
So why do you need to know all this? Because life depends on it. When we breathe in air, the oxygen in that air is carried by blood throughout the body and to each of our cells. The cells take in the oxygen and give off carbon dioxide in the process of making ATP. The carbon dioxide molecules are circulated back to the lungs where it is exhaled and this is cellular respiration (Glycolysis + Krebs + Electron Transport Chain) in action.
Animals, like humans, can only survive a short time without oxygen before the cells in the body--particularly the brain--start to die. Breathing air is a vital function and everyone knows that if breathing stops, death occurs.
Animals can only survive a short time without oxygen

11. Resources
Rainbowresource.com
End of presentation