1/25/2018 The Working Cell: Energy from Food Chapter 7 SR

7.1 Sunlight Powers Life!

A. Obtaining Food

What is an autotroph? An organism that can make its own glucose (food) “self-feeder” An organism that can make its own glucose (food) Ex: plants, algae

Photosynthesis Using the sun’s energy to change H2O and CO2 into glucose (C6H12O6)

Producers “produce” glucose for themselves and other organisms

What is a heterotroph? Organisms that cannot make their own food “other-feeder” Organisms that cannot make their own food Ex: humans, mushrooms

Consumers Gets food by eating producers or other consumers

B. Harvesting the Energy in Food

The energy of the sun keeps organisms alive! Cycle of materials between organisms Cycle within cells The energy of the sun keeps organisms alive! Staying alive

Written Summary The products of photosynthesis are the reactants in cell respiration (O2 & C6H12O6) The products of cell respiration are the reactants in photosynthesis (CO2 & H2O)

7.2 Food Stores Chemical Energy

Chemical Energy Is stored energy with the potential to do work.

Chemical Energy Found in: Carbohydrates Fats Protein

Used for Biological Work Chemical Energy The energy is found in the BONDS! Used for Biological Work

Putting chemical energy to work Complex organic molecules are broken down in cellular respiration

Putting chemical energy to work Cellular Respiration breaks bonds & converts chemical energy into ATP and heat.

Putting chemical energy to work -40% of energy from food used in biological work -60% lost as heat. Some heat lost is used to keep your body warm.

Calories: Units of Energy calorie = amount of energy needed to raise the temperature of 1 g of water by 1°C.

7.3 ATP Provides Energy for Cellular Work

How ATP Packs Energy When ATP is hydrolyzed it breaks a bond that releases energy The energy is used to do biological work

High energy bonds ATP

Available to do biological work ATP ADP Enzyme Energy Available to do biological work

Dehydration Synthesis Available to do biological work Energy Hydrolysis ADP + P ATP Dehydration Synthesis Energy From glucose

Like a re-chargeable battery ATP is constantly recycled in your cells!!! Like a re-chargeable battery

Cellular respiration converts energy 7.5 Cellular respiration converts energy in food to energy in ATP

Structures in cellular respiration Cell Membrane has channels for diffusion of glucose. allows O2, CO2, H2O to diffuse in and out of cell.

Structures in cellular respiration Cytoplasm has enzymes needed to do glycolysis (1st stage in cellular respiration).

Structures in cellular respiration Mitochondria has enzymes & coenzymes needed to continue aerobic cellular respiration (2nd & 3rd stages)

Overall Equation for Aerobic Cellular Respiration

Cytoplasm High-energy electrons carried mainly by NADH High-energy electrons carried by NADH Mitochondrion Glycolysis Krebs Cycle Electron Transport 2 Pyruvic acid Glucose

Glycolysis (Stage 1) glucose cutting process 1. Occurs in cytoplasm 2. Specific enzymes are required 3. Uses glucose - breaks it in half.

Glycolysis (Stage 1) glucose cutting process 4. Anaerobic phase – no oxygen required 5. Net ATP produced = 2 6. Energy from glucose is transferred to coenzymes (NADH)

Glycolysis (Stage 1) glucose cutting process 7. Produces two molecules of pyruvic acid. Glucose  2 pyruvic acids 2ADP +2P 2 ATP

Glucose C6H12O6 H H C OH O C H H H C C OH H HO OH C C H OH 1/25/2018 Chapter 7 SR

1/25/2018 Glucose C6H12O6 Chapter 7 SR

1/25/2018 C6 Glucose C3 2 Pyruvic Acid Chapter 7 SR

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Cytoplasm High-energy electrons carried mainly by NADH High-energy electrons carried by NADH Mitochondrion Glycolysis Krebs Cycle Electron Transport 2 Pyruvic acid Glucose

Mitochondrial Events:

Pyruvic Acid enters the mitochondria Specific enzymes are required Krebs Cycle (Stage 2) Pyruvic Acid enters the mitochondria Specific enzymes are required Pyruvic Acid C-C Bonds are broken

H (Energy & electrons) picked up by NAD forming NADH CO2 is produced Krebs Cycle (Stage 2) ATP produced = 2 H (Energy & electrons) picked up by NAD forming NADH CO2 is produced (3 C’s of Pyruvic Acid leave as CO2 )

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Electron Transport Chain (Stage 3) Occurs in mitochondria Specific enzymes are required Aerobic phase– oxygen required H+ ions and energy taken from coenzymes (NADH) ATP produced = 32-34 H2O is produced

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Total ATP Production if Glucose goes through Glycolysis, Kreb’s Cycle and ETC: 36-38 ATP

Aerobic Cellular Respiration

Some cells can harvest energy without oxygen 7.6 Some cells can harvest energy without oxygen

Fermentation (anaerobic cellular respiration) Does not use O2 Involves glycolysis and 1 or 2 steps Occurs in cytoplasm Net ATP produced = 2

A. Muscle cells in oxygen debt Lactic acid produced from fermentation in muscle cells causes muscle fatigue Lactic Acid fermentation Pyruvic acid Lactic Acid

B. Fermentation by bacteria in milk Makes cheese and yogurt Lactic Acid fermentation Pyruvic acid Lactic Acid

C. Fermentation by bacteria, producing vinegar Variety of vinegar formed based on starting substance ex. Apple cider vinegar Acetic Acid fermentation Pyruvic acid Acetic Acid

D. Fermentation by yeast cells: Alcoholic beverages such as beer & wine formed from fruit or grains Bread dough rises due to CO2 production. Alcohol fermentation Pyruvic acid Alcohol + CO2

Lactic Acid fermentation Acetic Acid fermentation Is named by its product: Alcohol fermentation Lactic Acid fermentation Acetic Acid fermentation

Anaerobic vs. Aerobic Anaerobic respiration does not use O2 produces 2 ATP per glucose. Stage 1 only (glycolysis)

Aerobic vs. Anaerobic Aerobic respiration uses O2 produces 36- 38 ATP per glucose Stages 1, 2, & 3

We’ve seen what happens when there is not enough oxygen available, but what happens when there is not enough glucose available??

Amino Acids can be converted to glucose When there are low levels of glucose, the body converts other nutrients into glucose to maintain energy production

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Crash Course Cell Respiration https://www.youtube.com/watch?v=00jbG_cfGuQ