The Equations:
Cell Respiration:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy (ATP)
Photosynthesis:
6CO2 + 6H2O + light energy  C6H12O6 + 6O2
BIG PICTURE OF CELL RESPIRATION:
-process by which the mitochondria produce ATP by
breaking down organic compounds (food we eat).
-cells need “usable” forms of energy to function and
maintain homeostasis. ATP is the usable form.
Flowchart of Cell Respiration
Step 1: Glycolysis
Function:
-food we eat is converted to pyruvic acid (2 molecules pyruvate).
-anaerobic (no oxygen)
Location:
cytosol of the eukaryotic cell
Reactants:
organic compounds (food), NAD+ & ADP
Products:
2 pyruvic acid (pyruvate)
2 NADH (energy)
2 ATP’s (energy)
Energy Yield:
2 ATP’s
Step 2 (if oxygen is present):
Aerobic Respiration
-pyruvic acid is converted to Acetyl Coa prior to
entering the Kreb’s Cycle.
Function:
1. Krebs cycle- produce NADH & FADH2
2. ETC & Chemiosmosis- produce ATP
Location: eukaryotes- Krebs in the mitochondrial
matrix & the ETC is in the inner mitochondrial
membrane.
prokaryotes- cytoplasm &
cell membrane
Krebs Cycle (Citric Acid Cycle)
Reactants:
Acetyl CoA, NAD+ & FAD+
Products:
CO2 (given off as a waste product)
NADH
FADH
ATP (2 molecules)
Electron Transport Chain & Chemiosmosis
(uses enzyme: ATP synthase)
Reactants:
NADH, FADH2
Products:
NAD+ & FAD+ get recycled
water (given off as a waste product)
ATP (34 molecules)
Fermentation: (if no oxygen is present)
Two common fermentation pathways:
1. Lactic Acid Fermentation
2. Alcoholic Fermentation
Function:
-always start with glycolysis
-no oxygen is present
-NADH
NAD+ (recycled back to glycolysis)
-produce either lactic acid or alcohol.
Location: cytosol
*No oxygen = no ATP production.
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.
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.
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.