CELLULAR RESPIRATION 1

CHEMICAL ENERGY & FOOD One gram of glucose releases 3811 calories of energy  Calorie-amt of energy needed to raise the temp. of 1g water 1°C Calories on food labels is actually a kilocalorie 2

All activity burns calories If # calories is less than that burned then the body consumes itself If # calories taken is more than burned then they are stored in the form of fat 3

What Is ATP? ATP = energy used by all Cells ATP = energy used by all Cells Adenosine Triphosphate Adenosine Triphosphate organic molecule containing high-energy Phosphate bonds organic molecule containing high-energy Phosphate bonds 4

Chemical Structure of ATP 3 Phosphates Ribose Sugar Adenine Base 5

What Does ATP Do for You? It supplies YOU with ENERGY! 6

How Do We Get Energy From ATP? By breaking the high- energy bonds between the last two phosphates in ATP 7

CELLULAR RESPIRATION Cellular respiration- releases energy by breaking down food/glucose in the presence of O 2 6O 2 + C 6 H 12 O 6 →6CO 2 + 6H 2 O + energy (ATP) 8

Where Does Cellular Respiration Take Place? It actually takes place in two parts of the cell:It actually takes place in two parts of the cell: Glycolysis occurs in the Cytoplasm Krebs Cycle & ETC Takeplace in the Mitochondria Krebs Cycle & ETC Take place in the Mitochondria 9

Review of Mitochondria Structure Smooth outer MembraneSmooth outer Membrane Folded inner membraneFolded inner membrane Folds called CristaeFolds called Cristae Space inside cristae called the MatrixSpace inside cristae called the Matrix 10

Diagram of the Process Occurs in Cytoplasm Occurs in Matrix Occurs across Cristae 11

CELLULAR RESPIRATION – STAGES 1. glycolysis, 2.Kreb’s cycle, 3.electron transport chain (ETC) 12

GLYCOLYSIS Doesn’t need O 2 Occurs in cytoplasm metabolic pathway found in all living organisms What goes in? glucose What comes out? Pyruvic acid + 2 ATP 13

Glycolysis- 1 glucose molecule is broken in half, making 2 pyruvic acid molecules Glycolysis releases energy, but also needs energy (needs 2 ATP, makes 4) 4 high energy electrons are removed and carried by NAD+ (NADP+ in psyth) to other molecules 14

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**BUT if too much ATP is made via glycolysis then all the NAD+ get filled quickly & so the process stops 16

ANAEROBIC RESPIRATION (w/o O 2 ) If O 2 is not present after glycolysis then fermentation may occur Fermentation-releases energy from food by making ATP w/o O 2 17

FERMENTATION: alcohol & lactic acid Alcohol  yeast & other microorganisms form ethyl alcohol & CO 2 from sugar  Makes bread rise, makes wine, beer 18

Lactic acid  in cells pyruvic acid is changed to lactic acid  Made in muscles during strenuous exercise  B/c the body can’t supply enough O 2 to the tissues 19

Buildup of lactic acid hurts, this is the cause of sore muscles after the 1 st few minutes of exercise Some organisms also make lactic acid as a waste product & are used to make many foods & drinks like cheese, yogurt, sour cream, etc… 20

AEROBIC RESPIRATION (w/O 2 ) if O 2 is present then glycolysis enters the 2 nd step of respiration;  The Kreb’s cycle 21

KREB’S CYCLE Needs O 2 Occurs in mitochondria What goes in? Pyruvic acid What comes out? 3CO 2, 1ATP, 4NADH, & 1 FADH 2 CO 2 is exhaled 22

ATP is used for cellular processes NADH & FADH 2 is used to make large amounts of ATP 23

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ELECTRON TRANSPORT CHAIN (ETC) Where?- membrane of mitochondria What goes in? NADH, FADH 2 What comes out? ~34-36 ATP 25

High energy e-’s carried by NADH & FADH 2 from Kreb’s cycle pump H+ ions across the membrane The H+ power ATP synthase to convert ADP to ATP 26

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Totals 1 glucose = ~36 ATP Glycolysis=makes 4 uses 2 = 2; in cytosol Kreb’s cycle + ETC = ~34 ATP; in mitochondria 29