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 & H 2 O

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: 1.Aerobic: needs Oxygen 2.Anaerobic: does NOT need Oxygen 3 Stages: 1.Glycolysis 2.Citric Acid Cycle (Krebs Cycle) 3.Electron Transport Chain

CELLULAR RESPIRATION 3 Stages: 1.Glycolysis = ANAEROBIC 2.Citric Acid Cycle (Krebs Cycle) = AEROBIC 3.Electron Transport Chain = AEROBIC

CELLULAR RESPIRATION 1.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) NOT EFFICIENT

CELLULAR RESPIRATION

STOP & REVIEW 1. What term is used to describe a process when no oxygen is needed? 1. Anaerobic 2. What term is used to describe a process when oxygen is needed? 2. Aerobic 3. Which of the three steps in cellular respiration happens without oxygen? 3. Glycolysis 4. Where does that process occur? 4. Cytoplasm (can prokaryotes carry out glycolysis)? 5. In this process, glucose is broken down into? 5. 2 Pyruvates 6. How many ATP are made by that process? 6. 4 ATP (But only 2 ATP are gained) 7. What else is made in this process to run the next process? 7. 2 NADH

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

CELLULAR RESPIRATION

3.Electron Transport Chain -Takes place in and across inner membrane of mitochondria. NADH from glycolysis & Krebs and FADH 2 from Krebs unloads electrons at ETC. Energy used to make ATP. Result: 32 ATP is made H 2 O also made

STOP & REVIEW 1. What are the second two steps called in cellular respiration? 1. Kreb’s Cycle, and the ETC 2. Are they aerobic or anaerobic? 2. Aerobic 3. Where do they occur? 3. In the Mitochondria 4. What is produced by the second step? 4. 2 ATP, CO 2, NADH, FADH 5. What is produced in the final step? ATP & H 2 O 6. How many ATP total are made for the cell from the breakdown of one glucose molecule? ATP 7. What is released at the end through oxidative phosphorylation? 7. 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 –2 Kinds: 1.Lactic Acid 2.Alcoholic Both kinds only use GLYCOLYSIS –How many ATPs does that mean they make? 2 net ATP

CELLULAR RESPIRATION 1.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 2.Alcoholic Anaerobic Carried out by some bacteria and yeast Used to bake bread and make wine Produces CO 2, 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 PhotosynthesisCellular Respiration Food ______________Food _______________________ Energy from ___ stored in ________Energy of ________ released Carbon dioxide __________Carbon dioxide ____________ Oxygen ____________ Oxygen _____________ Produces _______ from PGALProduces ___________________ ______________ light _______________ light Occurs only in _______________ _________ Occurs in __________________

Let us do some comparisons! Photosynthesis vs. Cellular Respiration PhotosynthesisCellular Respiration Food synthesizedFood broken down Energy from sun stored in glucoseEnergy of glucose released Carbon dioxide taken inCarbon dioxide given off Oxygen given off Oxygen taken in Produces sugars (CROSS OUT PGAL) Produces CO2 and H 2 O Requires light Does not require 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)_____________________ ________ acid ___ ATP carbon dioxide alcohol ___ ATP ____________________ _________ ____ ATP

Let us do some comparisons! Fermentation vs. Cellular Respiration Comparison of Fermentation to Cellular Respiration Lactic Acid AlcoholicCellular respiration glucose glycolysis (pyruvic acid) lactic acid 2 ATP glucose glycolysis (pyruvic acid) carbon dioxide alcohol 2 ATP36 ATP water carbon dioxide

Check It! D. the Calvin cycle C. the light-independent reaction B. cellular respiration A. photosynthesis 1.The process by which mitochondria break down food molecules to produce ATP is called ________.

Check It! B. glycolysis, the citric acid cycle, and the electron transport chain A. Carbon fixation, the Calvin cycle, and the electron transport chain 2.The three stages of cellular respiration in order are ________. D. the light-dependent reactions, the citric acid cycle and the electron transport chain C. glycolysis, the electron transport chain, and the citric acid cycle

Check it! 3.Which of the following yields the greatest net ATP? D. Cellular respiration C. Calvin cycle B. Alcoholic fermentation A. Lactic acid fermentation

Overall Energy Transfers CPE (Glucose) > CPE (ATP)

Equation for Cellular Respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + 36ATP  Like the reverse of photosynthesis 