Cellular Respiration & Fermantation Unit 3: Energy Transformations Chapter 9,

Review: Producers Producers get their energy from the sun. Producers convert this light energy into stored chemical energy (glucose). This process is called photosynthesis.

Review: Consumers Consumers get their energy from the producers. Consumers convert stored chemical energy (glucose) into usable chemical energy Adenosine triphosphate (ATP). This process is called cellular respiration.

BioTheme: Interdependence! Photosynthesis: 6 H2O + 6 CO2 + energy (sun) → C6H12O6 + 6 O2 Aerobic Cellular Respiration: C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy (ATP)

Where do organisms get energy? Food molecules contain chemical energy that is released when their chemical bonds are broken. Energy stored in food is expressed in units called calories. Calorie – the amount of energy needed to raise the temp. of 1 gram of water 1 degree Celsius.

Calorie on food labels = 1 kilocalorie or 1000 calories Calorie (C) Calorie on food labels = 1 kilocalorie or 1000 calories 1 g Carbohydrate = 4 calories 1 g Protein = 4 calories 1 g Fat = 9 calories

Cellular Respiration (aerobic) Cellular respiration is the process by which glucose (C6H12O6) is broken down to release energy for making ATP, another form of chemical energy.

Aerobic Respiration – Equation C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP food (glucose, a carbohydrate) oxygen water carbon dioxide Does this look familiar?

Do only animals respire? Or do plants respire too? The BIG Question is… Do only animals respire? Or do plants respire too? Only plants perform photosynthesis Plants AND animals perform cellular respiration! (Can you explain why??)

Muscle cells carrying out Breathing O2 CO2 Lungs CO2 O2 Bloodstream Figure 6.2 The connection between breathing and cellular respiration. Muscle cells carrying out Cellular Respiration Glucose + O2 CO2 + H2O + ATP

High-energy electrons NADH High-energy electrons carried by NADH Mitochondrion NADH FADH2 and GLYCOLYSIS OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis) CITRIC ACID CYCLE Glucose Pyruvate Cytoplasm Inner mitochondrial membrane Figure 6.6 An overview of cellular respiration. CO2 CO2 ATP ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation Oxidative phosphorylation

3 stages of Cellular Respiration Glycolysis Krebs cycle Electron transport

Significant ATP Production Aerobic cellular respiration releases energy SLOWLY, using oxygen to convert ONE molecule of glucose to 36 ATP!

Anaerobic Respiration What happens when cells don’t have enough oxygen? Some organisms live in an oxygen-free environment. How do they get their energy?

Energy and Exercise The body uses different pathways to release energy. For short, quick bursts of energy, the body uses ATP already in muscles as well as ATP made by lactic acid fermentation. For exercise longer than about 90 seconds, cellular respiration is the only way to continue generating a supply of ATP.

Fermentation Fermentation releases energy from food molecules by producing ATP without oxygen.

Lactic Acid Fermentation lactic acid fermentation produces lactic acid occurs in most organisms, including humans used to produce beverages such as buttermilk and foods such as cheese, yogurt, and pickles

Lactic acid fermentation can supply enough ATP to last about 90 seconds. However, extra oxygen is required to get rid of the lactic acid produced. Following intense exercise, a person will huff and puff for several minutes in order to pay back the built-up “oxygen debt” and clear the lactic acid from the body.

Alcoholic Fermentation alcoholic fermentation produces ethyl alcohol and carbon dioxide occurs in yeast and a few other microorganisms produces alcoholic beverages and causes bread dough to rise

Cellular Respiration (anaerobic) Anaerobic respiration is also called fermentation, or the process by which energy is released from glucose when oxygen is NOT available. This process allows organisms to continue to produce energy until oxygen is available. However, this process only releases 2 ATP per molecule of glucose.

Alcoholic Fermentation Anaerobic way of converting energy for yeast and other microorganisms Glucose broken down to produce alcohol, CO2 and energy (ATP) C6H12O6  ethanol + CO2 + 2 ATP EX: baking bread with yeast fermenting wine & beer

Fermentation - Bread Source of sugar? DOUGH! (sugar and/or flour) Yeast use up the O2 and ferment sugar Produce CO2, which is trapped within tiny bubbles & results in the dough rising Produce ethanol, which evaporates in the baking process

Fermentation - Wine Source of sugar? GRAPES! Yeast use up the O2 and ferment sugar Produce CO2 (kept only in champagne) Produce ethanol (% alcohol varies based on sugar content of grapes and # of fermentations)

Fermentation - Beer Source of sugar? BARLEY! Yeast use up the O2 and ferment sugar Hops are added as a preservative and for added flavor Produce CO2 and ethanol also Various carbohydrates can be used to make alcohol – including wheat, rice, and potatoes!

Other side effects of fermentation?! “Drunken Swedish moose drowns after fermented apple binge” http://www.usatoday.com/news/offbeat/2006-11-24-moose_x.htm “Drunk Moose Invade Seniors Home” http://www.wtopnews.com/index.php?nid=456&sid=620430

Strenuous Exercise Lactic acid is produced by your muscle cells during rapid exercise when the body cannot supply enough O2 to tissues. Without enough O2, the body is NOT able to produce all of the ATP that is required. The buildup of lactic acid can cause painful burning in your muscles!

Minimal ATP Production In the absence of oxygen, anaerobic respiration only releases 2 ATP for each molecule of glucose broken down.

Comparing ATP Production First, your body breaks down glucose through aerobic respiration to produce 36 ATP per glucose molecule; however, this is a slow process. When muscle cells cannot get enough O2 they break down glucose through lactic acid fermentation to produce 2 ATP per glucose… Therefore, AEROBIC RESPIRATION is much more efficient in terms of ATP production – 36 ATP compared to 2 ATP!

Aerobic Training Ex: long runs, biking, swimming Can increase the size and number of mitochondria in muscle cells Can increase the delivery of O2 to muscles by improving the heart and lungs

Anaerobic Training Ex: sprints, strides, quick bursts of energy Increase the glycogen levels in the muscles Increase body’s tolerance to lactic acid

Long Term Energy Storage The body stores energy in the form of the carbohydrate glycogen. These glycogen stores are enough to last for 15 to 20 minutes of activity. After that, the body begins to break down other stored molecules, including fats, for energy.