CELLULAR RESPIRATION Let’s take a look back! Photosynthesis: light energy makes glucose (chemical energy) Occurs only in plants or organisms with plastids like chlorophyll Carbon dioxide is taken in Oxygen is given off Also requires light & H2O

CELLULAR RESPIRATION Cellular Respiration: chemical process where carbohydrates are broken down to be a quick source of ATP Location: mostly within Mitochondria, first part in cytoplasm CPE (Food)  CPE (ATP)

CELLULAR RESPIRATION Two Types: 3 Stages: Aerobic: needs Oxygen Anaerobic: does NOT need Oxygen 3 Stages: Glycolysis Citric Acid Cycle (Krebs Cycle) Electron Transport Chain

CELLULAR RESPIRATION 3 Stages: Glycolysis = ANAEROBIC Citric Acid Cycle (Krebs Cycle) = AEROBIC Electron Transport Chain = AEROBIC

CELLULAR RESPIRATION Glycolysis: means “breaks down glucose” Occurs in cytoplasm COSTS 2 ATPs to start reaction Breaks glucose down to Pyruvic Acid (pyruvate) (goes to Krebs Cycle) Makes total of 4 ATPs At end of reaction, net of 2 ATP available to cell, and NADH (energy carrier – will go to ETC) NOT EFFICIENT

CELLULAR RESPIRATION

STOP AND REVIEW What is the purpose of glycolysis? To break down glucose into 2 pyruvate Is glycolysis aerobic or anaerobic? anaerobic Where does glycolysis occur? cytoplasm How many ATP are required to start glycolysis? 2 What is the total number of ATP produced? Net amount of ATP produced? 4, 2

CELLULAR RESPIRATION Citric Acid Cycle (Krebs Cycle) Occurs in Mitochondria (matrix: space enclosed by inner membrane) Aerobic 2 Cycles occur at same time (1 for each pyruvate) Each cycle produces 1 ATP

CELLULAR RESPIRATION Citric Acid Cycle (Krebs Cycle) Yields (Produces): 2 Net ATP NADH and FADH2 Go to ETC Carbon Dioxide Released as waste

CELLULAR RESPIRATION

STOP AND REVIEW What is another name for the Krebs Cycle? Citric Acid Cycle Where does the Krebs Cycle occur? Mitochondrial matrix Is the Krebs cycle aerobic or anaerobic? aerobic What is produced? NADH, FADH2, 2 ATP, CO2

CELLULAR RESPIRATION Electron Transport Chain -Takes place in and across inner membrane of mitochondria. NADH from glycolysis & Krebs and FADH2 from Krebs unloads electrons at ETC. Energy used to make ATP. Result: 32 ATP is made H2O also made

STOP AND REVIEW Where does the ETC take place? Inner membrane of mitochondria Is the ETC aerobic or anerobic? aerobic Where does the energy come from to make ATP? NADH and FADH2 What is made during the ETC? 32 ATP, Water

CELLULAR RESPIRATION END RESULT: 36-38 ATP made from all 3 Stages Oxidative Phosphorylation Oxygen is final electron acceptor; water is formed ADP is converted to ATP by adding phosphate group But wait! What if there was not enough oxygen? Could cellular respiration still have taken place?

CELLULAR RESPIRATION YES! Anaerobic Respiration or FERMENTATION takes place!

CELLULAR RESPIRATION FERMENTATION Both kinds only use GLYCOLYSIS Lactic Acid Alcoholic Both kinds only use GLYCOLYSIS How many ATPs does that mean they make? 2 net ATP

CELLULAR RESPIRATION Lactic Acid Fermentation Anaerobic Produces burning feeling in muscle cells Occurs when body worked to point that more oxygen being used than taken in Produces LACTIC ACID and 2 ATP

CELLULAR RESPIRATION Alcoholic Anaerobic Carried out by some bacteria and yeast Used to bake bread and make wine Produces CO2, Ethyl Alcohol, and 2 ATP

STOP AND REVIEW Where in the cell does fermentation take place? Cytoplasm Why does fermentation occur? Not enough oxygen or no mitochondria What organisms go through alcoholic fermentation? Yeast and some bacteria How many ATP does fermentation produce? 2 net ATP

Let us do some comparisons! Photosynthesis vs. Cellular Respiration Photosynthesis Cellular Respiration Food ______________ Food _______________________ Energy from ___ stored in ________ Energy of ________ released Carbon dioxide __________ Carbon dioxide ____________ Oxygen _____________ Oxygen ____________ Produces _______ from PGAL Produces ___________________ _______________ light ______________ light Occurs only in _______________ _________ Occurs in __________________

Let us do some comparisons! Photosynthesis vs. Cellular Respiration Photosynthesis Cellular Respiration Food synthesized Food broken down Energy from sun stored in glucose Energy of glucose released Carbon dioxide taken in Carbon dioxide given off Oxygen taken in Oxygen given off Produces CO2 and H2O Produces sugars Does not require light Requires light Occurs only in presence of chlorophyll Occurs in all living cells

Let us do some comparisons! Fermentation vs. Cellular Respiration Comparison of Fermentation to Cellular Respiration Lactic Acid _____________ Cellular respiration _____________ ____________ ____________ glycolysis (____________) _________ (pyruvic acid) _____________________ carbon dioxide ____________________ ________ acid alcohol _________ ___ ATP ___ ATP ____ ATP

Let us do some comparisons! Fermentation vs. Cellular Respiration Comparison of Fermentation to Cellular Respiration Lactic Acid Alcoholic Cellular respiration glucose glucose glucose glycolysis (pyruvic acid) glycolysis (pyruvic acid) glycolysis (pyruvic acid) carbon dioxide carbon dioxide lactic acid alcohol water 2 ATP 2 ATP 36 ATP

Check It! The process by which mitochondria break down food molecules to produce ATP is called ________. A. photosynthesis B. cellular respiration C. the light-independent reaction D. the Calvin cycle

Check It! The three stages of cellular respiration in order are ________. A. Carbon fixation, the Calvin cycle, and the electron transport chain B. glycolysis, the citric acid cycle, and the electron transport chain C. glycolysis, the electron transport chain, and the citric acid cycle D. the light-dependent reactions, the citric acid cycle and the electron transport chain

Check it! Which of the following yields the greatest net ATP? A. Lactic acid fermentation B. Alcoholic fermentation C. Calvin cycle D. Cellular respiration