Cellular Respiration How do cells use food to make energy (ATP)? Chapter 9

Batteries of Life Adenosine Triphosphate – ATP Adenosine Triphosphate – ATP Adenosine Diphosphate – ADP Adenosine Diphosphate – ADP

AdenineRibose3 Phosphate groups ATP

Cellular Respiration The process that releases energy by breaking down food molecules in the presence of oxygen The process that releases energy by breaking down food molecules in the presence of oxygen C 6 H 12 O 6 + 6O 2 -> 6H 2 O + 6CO 2 + Energy C 6 H 12 O 6 + 6O 2 -> 6H 2 O + 6CO 2 + Energy

Main Types of Energy-Releasing Pathways Aerobic pathways Evolved later Require oxygen Start with glycolysis in cytoplasm Completed in mitochondria Anaerobic pathways Evolved first Don’t require oxygen Start with glycolysis in cytoplasm Completed in cytoplasm

3 Steps - When Oxygen is Present Glycolysis Glycolysis Krebs Cycle (Citric Acid cycle) Krebs Cycle (Citric Acid cycle) Electron Transport Chain (Oxidative Phosphorylation) Electron Transport Chain (Oxidative Phosphorylation)

Glucose Glycolysis Cytoplasm Pyruvic acid Electrons carried in NADH Krebs Cycle Electrons carried in NADH and FADH 2 Electron Transport Chain Mitochondrion Cellular Respiration: An Overview Mitochondrion

Glucose To the electron transport chain Glycolysis 2 Pyruvic acid

Glycolysis Glucose broken into 2 molecules of Pyruvic Acid Glucose broken into 2 molecules of Pyruvic Acid Oxygen not required Oxygen not required 2 ATP are used and 4 ATP and 2 NADH are produced 2 ATP are used and 4 ATP and 2 NADH are produced Occurs for a short time because NAD+ are used up Occurs for a short time because NAD+ are used up

Krebs Cycle When O 2 is present, pyruvic acid from glycolysis produces CO 2, ATP, NADH and FADH 2. When O 2 is present, pyruvic acid from glycolysis produces CO 2, ATP, NADH and FADH 2. 1 molecule of Glucose produces 2 turns of the cycle 1 molecule of Glucose produces 2 turns of the cycle

Citric Acid Production The Krebs Cycle Mitochondrion

Electron Transport Chain NADH and FADH 2 made in glyoclysis and the Krebs Cycle are used to make ATP NADH and FADH 2 made in glyoclysis and the Krebs Cycle are used to make ATP Oxygen accepts low energy electrons and H+ to form water. Oxygen accepts low energy electrons and H+ to form water. ATP produced when H+ diffuses across the membrane ATP produced when H+ diffuses across the membrane

Electron Transport Chain Electron Transport Hydrogen Ion Movement ATP Production ATP synthase Channel Inner Membrane Matrix Intermembrane Space Mitochondrion

What does 1 molecule of glucose produce? ATP ATP

How do we measure energy? calorie- the amount of energy needed to raise the temp of 1 g of water 1 degree celsius. calorie- the amount of energy needed to raise the temp of 1 g of water 1 degree celsius. IMPORTANT NOTE FOR YOUR LIFE IMPORTANT NOTE FOR YOUR LIFE Food is labeled ___Calories/serving Food is labeled ___Calories/serving Capital letter means Kilocalories = 1000 calories. Capital letter means Kilocalories = 1000 calories. Package tells you how much energy the food can give you! Package tells you how much energy the food can give you!

What happens when O 2 isn’t available? Fermentation Fermentation 2 Types 2 Types occurs after glycolysis occurs after glycolysis anaerobic - without oxygen anaerobic - without oxygen Alcohol Fermentation Alcohol Fermentation Lactic Acid Fermentation Lactic Acid Fermentation

Alcohol Fermentation

Baking Yeasts during this process release carbon dioxide which causes bread to rise Yeasts during this process release carbon dioxide which causes bread to rise

Glucose Pyruvic acid Lactic acid Lactic Acid Fermentation

The Burn Large muscles that run out of oxygen quickly build up lactic acid which causes a painful burning sensation. Large muscles that run out of oxygen quickly build up lactic acid which causes a painful burning sensation. This occurs in animal cells This occurs in animal cells

Quick Energy - Anaerobic 4 seconds of ATP in the cell 4 seconds of ATP in the cell 5 seconds - 90 seconds - Lactic Acid Fermentation 5 seconds - 90 seconds - Lactic Acid Fermentation Oxygen debt and Heavy Breathing Oxygen debt and Heavy Breathing Anaerobic training builds up glycogen in the muscles and develops lactic acid tolerance Anaerobic training builds up glycogen in the muscles and develops lactic acid tolerance

Priscah Jeptoo: winner for women 2:25:24 Geoffrey Mutai: winner for men: 2:08:07 NYC Marathon 2013

Long-Term Energy - Aerobic Cellular Respiration after 90 seconds Cellular Respiration after 90 seconds Glycogen (Carbs) during the first minutes Glycogen (Carbs) during the first minutes Fats after 20 minutes Fats after 20 minutes Aerobic activity increases the size and number of mitochondria and increase oxygen delivery by improving the heart and lungs Aerobic activity increases the size and number of mitochondria and increase oxygen delivery by improving the heart and lungs

Where does a runner get energy for a 5K race? 1st- any available ATP 1st- any available ATP 2 nd - glycolysis and lactic acid fermentation 2 nd - glycolysis and lactic acid fermentation 3 rd - cellular respiration 3 rd - cellular respiration Break down sugars Break down sugars When out of sugars, break down fats When out of sugars, break down fats 4 th - sometimes revert back to glycolysis and lactic acid fermentation if their body is not fit enough for the distance/terrain. 4 th - sometimes revert back to glycolysis and lactic acid fermentation if their body is not fit enough for the distance/terrain.

Where does your body “look” for energy? 1. Carbs (Glucose for CR) 1. Carbs (Glucose for CR) When out of carbs… When out of carbs… 2. Fats 2. Fats When out of fats… When out of fats… 3. Proteins 3. Proteins When out of proteins…you are dead. When out of proteins…you are dead.

Creatine Creatine Phosphate donates a phosphate to ADP to make more ATP Creatine Phosphate donates a phosphate to ADP to make more ATP Prolongs the 4 seconds before lactic acid fermentation Prolongs the 4 seconds before lactic acid fermentation Allows for more repetitions and more intense workouts Allows for more repetitions and more intense workouts If abused could lead to kidney and liver problems If abused could lead to kidney and liver problems