1. Cellular Respiration

2. How do living things get energy?
Living things get the ENERGY they need from the breakdown of glucose (sugar)
ATP=Energy

3. Question:
In what kinds organisms does cellular respiration take place?

4. Cellular respiration take place in Plants and Animals
Plants – Autotrophs: self-producers.
Animals - Heterotrophs: consumers.

5. Cellular Energy All organisms need a source of energy.
Heterotrophs use the organic compounds in food for energy sources.
Before energy in complex carbohydrates can be used by cells, it must be broken down into simple sugars like glucose.
This breakdown of glucose is done by
our digestive system.

6. Mitochondria Organelle where cellular respiration takes place. Inner
membrane space
Matrix
Cristae
Outer
membrane
Inner
membrane

7. Cellular Respiration

8. Cellular Respiration C6H12O6 + 6O2  6CO2 + 6H2O + energy
The process that releases energy (ATP) by breaking down food molecules in the presence of oxygen.
Requires food molecules ex: Glucose (sugar) and Oxygen. Gives off carbon dioxide, water, and Energy.
C6H12O6 + 6O2  6CO2 + 6H2O + energy
glucose
ATP

9. Summary All our cells need energy
ATP is the energy that the cells use for all life processes.
The cell makes ATP by breaking down a sugar called glucose.
Glucose is the energy of the body.
ATP is the energy of the cell

10. Steps in cellular respiration
Step one: is always Glycolysis.
Glyco = sugar : lysis= breaking/ split
Glycolysis is splitting glucose
Step two: depends on whether oxygen is present or not.

11. Step One Glycolysis
Glycolysis is the process in which one molecule of glucose (6 Carbons) is broken “in half”, producing two molecules of pyruvic acid, a 3-carbon compound.
Occurs in CYTOPLASM of cell. Video Clip

12. Glycolysis 2 ATP needed to begin glycolysis.
4 ATP produced when its done.
NET gain 2 ATP. (4 – 2 = 2)
NADH is an electron carrier.
Glycolysis starts w/ ONE GLUCOSE
Ends with TWO PYRUVIC ACID
Video clip

13. Step Two Oxygen Present or not?
(No) If oxygen is not present (anaerobic) Step two is Fermentation
(Yes) If Oxygen is PRESENT (aerobic) step two is the Krebs Cycle & Electron Transport Chain

14. Fermentation (without oxygen)
Chemical Pathways
Glucose
Krebs cycle
Electron transport
Glycolysis
Alcohol or lactic acid
Fermentation (without oxygen)

15. Oxygen is not present. Fermentation:
Two types of fermentation
1. Alcoholic Fermentation
Used by Yeast and a few other microorganisms.
Produces alcohol and carbon dioxide from the three carbon pyruvic acid.
2. Lactic Acid Fermentation
Used by Bacteria and human muscle cells.
Produces lactic acid from the three carbon pyruvic acid.

16. Oxygen is present Krebs Cycle- Step 2 Electron Transport Chain- Step 3
Occurs in mitochondria (matrix)
2 molecules of ATP is generated per glucose.
CO2 is produced and released.
Electron Transport Chain- Step 3
Takes place in mitochondria (inner membrane).
32 molecules of ATP are produced per glucose molecule.

17. Krebs Cycle (Step 2 oxygen)
When oxygen is present such as in muscles, step two in cellular respiration is the Krebs Cycle
Occurs in mitochondria
Pyruvic acid is changed in a series of reactions.
These reactions produce high-energy electron carriers to be used in the electron transport chain
NAD+ and FAD+ are the high energy electron carriers
H+ is the electron that needs to be carried.
They turn into NADH and FADH2 when carrying electrons and provide the energy to drive the Electron Transport Chain.
2 molecules of ATP is generated per glucose.
CO2 is produced and released.

18. Electron Transport Chain (Step 3 Oxygen)
Takes place in mitochondria (inner membrane).
Series of proteins accept high energy electron pairs from NADH and FADH2.
NADH and FADH2 (Energy taxi dropping off energy)
Oxygen bonds with 2 hydrogens (final electron acceptor) to form H20
32 molecules of ATP are produced per glucose molecule.

19. ATP TOTAL ATP YIELD 02 ATP –Glycolysis 02 ATP Krebs 32 ATP - ETC
36 ATP - TOTAL Net
ATP

20. In Mitochondria with oxygen present
In Cytoplasm
NADH and FADH2
Krebs Cycle
Electron Transport
Glycolysis
2 ATP
2 ATP
32 ATP

21. Electrons carried in NADH
in NADH and
FADH2
Pyruvic acid
Glucose
Glycolysis
Cytoplasm
Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria.
Mitochondrion 2 2 32

22. ADP  ATP
Energy Released
Video Clip

23. Summary Step one is always glycolysis.
Step two depends on whether or not oxygen is present.
If it is not, then step two is fermentation, (anaerobic respiration)
If it is, then step two is the Krebs Cycle and step 3 is the electron transport chain.
In the process, organic glucose is converted to inorganic CO2

24. If oxygen is present, its called Aerobic respiration, and 36 ATP are created.
During anaerobic respiration or fermentation, 2 ATP are created.
ATP is the universal energy molecule, meaning that all living organism use it as an energy source.
Notice that much more ATP is made when oxygen is present.

25. How does glucose get into the body?
Through the foods you eat.
You eat a piece of bread, which is made of large carbohydrate molecules.
Your body breaks the large carbs into tiny sugars during digestion.
It starts with the saliva in the mouth, then in the stomach and finally as the food passes through intestines.
When the carbs reach the large intestines, they are broken down so small that they get absorbed in the blood. The small sugars are monosaccharides
Glucose is one of these monosaccharides.
The red blood cells then carry the small sugars to the cells that need them.

26. Identify the cellular process that most likely produced the CO2 in the body cell
Explain why carbon dioxide moves into red blood cells by diffusion rather than active transport.