Post on 25-Dec-2015
Biology Honors
First, a little about ATP• ATP– the energy that our cells
use• Cells use glucose to make
ATP• When the cell needs energy, it
breaks ATP• When ATP breaks, you get
ADP and energy• ADP gets a new phosphate,
becomes ATP again• Like charging a battery
ATP Cycle
The Mitochondrion
• Powerhouse of the cell
• Takes glucose and makes usable energy cellular ATP
• CELLULAR RESPIRATION
MitochondrionDraw one and label the parts as shown below
Cristae
Things you will need to know…
• Formula for cellular respiration:
• O2+ C6H12O6 CO2 + H2O + ATP
• Two hydrogen carrier molecules:– NAD (produces 3 ATP) – FAD (produces 2 ATP)
More on NAD and FADNAD + H = NADH
NADH - H=NAD
FAD + H= FADH
FADH - H=FAD
Cellular Respiration: Step 1• Glycolysis
Gly= refers to sugar
lysis= to break
Glycolysis: breaking sugar• Occurs in the cytoplasm
• 2 ATP molecules break glucose (6C) into two 3 carbon molecules
• Pyruvate or Pyruvic Acid (-ate / -ic = acid)
• 4 ATP are released in the end
• Hydrogen is released and picked up by NAD
Glycolysis: products
Per glucose molecule:
• ATP: make 4, use 2…..net gain = 2 ATP
• NADH: 2 NAD to 2 NADH
• Pyruvic acid: 2 (three carbon molecules)
Cellular Respiration: Step 1A
• Intermediate Step or the “Prep Step”
• Occurs only in presence of oxygen (Aerobic)
• Pyruvate loses one carbon, becomes acetyl-CoA
• Carbon dioxide is released
• NAD picks up hydrogen
Cellular Respiration: Step 2• Occurs in mitochondrial
matrix• Krebs Cycle or Citric Acid
Cycle• Acetyl CoA enters the cycle• Carbons are removed in
steps and released as 4 CO2
• 6 NADH & 2 FADH formed
• 2 ATP made
Cellular Respiration: Step 3• Electron Transport
Chain
• Occurs in inner membrane folds (cristae)
• NADH and FADH drop off hydrogen
• Oxygen picks up hydrogen, forms water
• 30 ATP made
Aerobic Respirationwhere it all happens
• Cytoplasm– glycolysis
• Matrix– Krebs
Cycle
• Inner membrane (cristae)– ETC
Anaerobic Respiration = NO OXYGEN
• AKA – Fermentation
• Only glycolysis occurs
• Pyruvic acid converts to lactic acid or ethanol (ethyl alcohol)
• Alcoholic fermentation—occurs in plants
• Lactic acid fermentation—occurs in animals
FermentationALCOHOL• Occurs in the
cytoplasm • Produces 2 alcohol, 2
CO2, 2 NAD+
• Makes only 2 ATP• Many commercial
uses
LACTIC ACID• Occurs in cytoplasm• Produces 2 NAD+, 2
lactic acid, no CO2
• Makes only 2 ATP• Causes muscle fatigue
Other Catabolic PathwaysFYI Only (Don’t write this!)
• Polysaccharides– First broken down into simple sugars– Enter glycolysis
• Fats– Broken down into 2 carbon molecules and
converted to acetyl coA– Enter Krebs cycle
• Proteins– Amino group removed, broken down into 2-
carbon molecules of acetyl CoA– Enter Krebs cycle
Photosynthesis & Cellular Respiration