Chapter 9 Respiration

The route from food to energy Glucose Then With oxygen Aerobic Respiration Without oxygen Fermentation Alcoholic Lactic Acid Goes through Glycolysis Not a lot of ATP made

The route from food to energy Glucose Then With oxygen Aerobic Respiration Without oxygen Fermentation Alcoholic Lactic Acid Goes through Glycolysis Not a lot of ATP made

Glycolysis  Breaks glucose down into 2 pyruvic acid molecules  Occurs in cytoplasm

Glycolysis  2 ATP invested  4 ATP generated  2 “net” ATP gained  Fast process!  But… runs out of NAD+ rather quickly  Process can’t go further

Glucose Then With oxygen Aerobic Respiration Without oxygen Fermentation Alcoholic Lactic Acid Goes through Glycolysis Not a lot of ATP made

Fermentation  Occurs after glycolysis  Does not require oxygen  Anaerobic  Switches NADH back into NAD+  Allows glycolysis to continue

Fermentation  Two flavors  Alcoholic fermentation  Lactic acid fermentation

Alcoholic fermentation  Done by yeast and other microbes  Formula  Makes bread, wine, and other food products

Lactic Acid Fermentation  Done in our muscles!  And other cells too  Formula

Lactic Acid Fermentation  Done in muscles during rapid exercise  Lactic acid causes the pH to drop in your cells  Makes you feel a burn, stop until you can get O 2 again  Makes cheese, yogurt, buttermilk, sour cream and other products

ALCOHOLIC LACTIC ACID

Glucose Then With oxygen Aerobic Respiration Without oxygen Fermentation Alcoholic Lactic Acid Goes through Glycolysis Not a lot of ATP made

Aerobic Respiration  After glycolysis  Only in eukaryotes  Require oxygen—aerobic  NOT THE SAME AS REGULAR RESPIRATION!

Where does aerobic respiration happen?  In the mitochondria!  Mitochondria are organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use

2 Main steps of Aerobic Respiration 1. Kreb’s cycle o Pyruvic acid is broken down into CO 2 in a series of energy- extracting reactions Also known as the Citric Acid Cycle 2 ATP are generated

Kreb’s Cycle

2 Main steps of Aerobic Respiration 2. Electron Transport Chain o Uses high energy electrons from the Kreb’s cycle to convert ADP into ATP o 32 ATP are produced

Comparing Aerobic Respiration to glycolysis and Fermentation  Glycolysis2 ATP  Fermentation0 ATP  Kreb’s Cycle2 ATP  Electron transport32 ATP  Anaerobic _________  Aerobic ___________ AEROBIC RESPIRATION is 18 TIMES MORE EFFICIENT!

Where to go for energy?  Instant energy—glycolysisLESS ATP  Fast energy—fermentation  Slow energy—cellular respirationMOST ATP