1. Cellular Respiration

2. The Equations… Photosynthesis: 6CO2 + 6H2O + energy  C6H12O6 + 6O2
(sun)
Cell Respiration:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy (ATP)

3. Cellular Respiration…What is it?
-process by which cells produce ATP by breaking down organic compounds.
Why is it important?
-cells need “usable” forms of energy to function and maintain homeostasis. ATP is the usable form.

4. Overview of Cell Respiration…

6. Pathway 1: Glycolysis Function: -anaerobic (no oxygen)
-organic compounds (sugar) is converted to pyruvic acid.
-ATP and NADH molecules are produced.
(reduction reaction)
Location: cytosol
Reactants: organic compounds (sugar)
Products: 2 pyruvic acid
2 NADH (energy)
2 ATP’s (energy)

7. Pathway 2 (if no oxygen is present): Fermentation
Function:
-no oxygen is present
-NADH NAD+ (recycled back to glycolysis)
Many types of fermentation pathways, but two of the more common are:
1. Lactic Acid Fermentation
2. Alcoholic Fermentation
Location: cytosol

8. Lactic Acid Fermentation
Reactants: pyruvic acid
NADH
Product: NAD+
lactic acid
-Lactic Acid Fermentation is important in the manufacturing of various foods. (yogurt, cheese)
-Athletes also experience Lactic Acid buildup…cramping and fatigue.

9. Alcoholic Fermentation
Reactants: pyruvic acid
NADH
Product: NAD+
alcohol
-Process occurs in plants and yeast.
-This process is important in making bread and alcohol products.

10. Pathway 2 (if oxygen is present): Aerobic Respiration
Function: two stages:
1. Krebs cycle
2. ETC & Chemiosmosis
-produce majority of the ATP
-pyruvic acid is converted to
Acetyl Coa
Location: eukaryotes- mitochondrial matrix (Krebs) & the inner mitochondrial membrane (ETC)
prokaryotes- cytoplasm & cell membrane

11. Krebs Cycle (Citric Acid Cycle)
Reactants: Acetyl CoA
Products: CO2 (given off as a waste product)
ATP (2 molecules)
NADH, FADH2

12. Electron Transport Chain & Chemiosmosis (uses enzyme: ATP synthase)
Reactants: NADH, FADH2
Products: ATP (34 molecules)
water (given off as a waste product)

13. Final Analysis:
Net production of ATP through aerobic respiration…38 ATP (2 from glycolysis 2 from Kreb’s and 34 from ETC/Chemiosmosis)
Aerobic Respiration is much more efficient in producing ATP! Why…oxygen is present.