Situation: the autotrophs have produced sugar and oxygen. Energy 6CO2 + 6H2O  C6H12O6 + 6O2 Now – how do we RELEASE the energy in that sugar?

Need to turn the sugar into ATP is the cell’s energy molecule ATP

What Does ATP Do for You? It supplies YOU with ENERGY!

How Do We Get Energy From ATP? By breaking the last P – P bond Adenine P P Adenine P P

How Does That Happen? An Enzyme! ATPase

When is ATP Made in the Body? During cellular respiration both plants & animals do it!

Cellular Respiration: releasing the energy in food as ATP

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

Cellular Respiration is the reverse of photosynthesis C6H12O6 + 6O2 6CO2 + 6H2O+ energy ATP

What are the Stages of Cellular Respiration? In cytoplasm 1. Glycolysis (sugar is split) In mitochondria: 2. The Krebs Cycle (citric acid cycle) 3. The Electron Transport Chain

ETC Krebs Cycle Glycolysis

Look at textbook pp 222 - 228

Step 1: Glycolysis Glucose 2 pyruvic acid C-C-C-C-C-C C-C-C + C-C-C http://www.northland.cc.mn.us/biology/Biology1111/animations/glycolysis.html

Mitochondria Organelle where cellular respiration takes place.

Step 2: Kreb’s Cycle C-C-C CO2 & a whole bunch of NADHs http://www.science.smith.edu/departments/Biology/Bio231/krebs.html

Electron Transport Chain High energy electrons used to convert ADP to ATP http://www.science.smith.edu/departments/Biology/Bio231/etc.html

ATP + H2O Glycolysis C-C-C-C-C-C O2 C-C-C CR: 36 NET ATP ETC Krebs Cycle CO2 + NADH ATP + H2O

Animation of CR: qcc. cuny Animation of CR: qcc.cuny.edu/BiologicalSciences/Faculty/DMeyer/respiration.html http://scholar.hw.ac.uk/site/biology/activity3.asp

But what happens when there is no oxygen present?

Only Glycolysis can occur C-C-C-C-C-C C-C-C ETC Krebs Cycle

Fermentation Occurs when O2 is NOT present Two types: AKA anaerobic respiration Two types: Lactic Acid fermentation (muscle cells) Alcoholic fermentation (yeast) Nets only 2 ATP (instead of 36)

Lactic Acid Fermentation Animals (pain in muscle after workout) C C C C C Glycolysis Pyruvic acid Lactic Acid glucose

Alcohol Fermentation glucose Pyruvic Ethanol Plants and Fungi  beer and wine C C C C C Glycolysis Pyruvic acid Ethanol glucose

Aerobic or Anaerobic Respiration

Question: Glucose (carbohydrate) is the main source of food for making ATP from cellular respiration. What other food molecules can be used in Cellular Respiration?

Other organic molecules used for fuel: 1. Carbohydrates: polysaccharides 2. Fats: glycerols and fatty acids 3. Proteins: amino acids