Cellular Respiration Let’s Review Is a chemical process that uses oxygen to convert chemical energy stored in organic molecules into another form of chemical energy – a molecule called ATP Cells in plants and animals then use the ATP as their main energy supply.

Energy The ability to perform work Ex: your heart muscle does work every time it beats Two basic forms of energy  Potential  kinetic

Potential Energy Is stored energy due to an object’s position or arrangement

Kinetic Energy Energy of motion Anything that is moving Kinetic - “motion”

Thermal Energy Energy that has been transferred From areas that are warmer to cooler

Chemical Energy Organic compounds store energy (potential) in the way their atoms are arranged. This is called chemical energy

ATP - Nature's Energy Store All living things, plants and animals, require a continual supply of energy in order to function. The energy is used for all the processes which keep the organism alive.

Before the energy can be used, it is first transformed into a form which the organism can handle easily. This special carrier of energy is the molecule adenosine triphosphate, or ATP.

Its Structure The ATP molecule is composed of three components. At the center is a sugar molecule, ribose  (the same sugar that forms the basis of RNA).

Attached to one side of this is a base (a group consisting of linked rings of carbon and nitrogen atoms); in this case the base is adenine. The other side of the sugar is attached to a string of phosphate groups. These phosphates are the key to the activity of ATP.

ATP consists of a base, in this case adenine (red), a ribose (magenta) and a phosphate chain (blue).

How it works ATP works by losing the endmost phosphate group when instructed to do so by an enzyme. This reaction releases a lot of energy, which the organism can then use to build proteins, contact muscles, etc

The reaction product is adenosine diphosphate (ADP),

ATP

ADP

Even more energy can be extracted by removing a second phosphate group to produce adenosine monophosphate (AMP).

AMP

When the organism is resting and energy is not immediately needed, the reverse reaction takes place and the phosphate group is reattached to the molecule using energy obtained from food or sunlight. he ATP molecule acts as a chemical 'battery', storing energy when it is not needed, but able to release it instantly when the organism requires it.

The Phosphorus Cycle The fact that ATP is Nature's 'universal energy store' explains why phosphates are a vital ingredient in the diets of all living things. Modern fertilizers often contain phosphorus compounds that have been extracted from animal bones.

These compounds are used by plants to make ATP. We then eat the plants, metabolise their phosphorus, and produce our own ATP. When we die, our phosphorus goes back into the ecosystem to begin the cycle again...

Cellular Respiration

catabolic, exergonic, oxygen (O 2 ) energy macromolecules (glucose)energy (ATP) water (H 2 O). A catabolic, exergonic, oxygen (O 2 ) requiring process that uses energy extracted from macromolecules (glucose) to produce energy (ATP) and water (H 2 O). C 6 H 12 O 6 + 6O 2  6CO2 + 6H 2 O + energy glucoseATP

Question: In what kinds organisms does cellular respiration take place? In what kinds organisms does cellular respiration take place?

Plants and Animals Plants - Autotrophs Plants - Autotrophs: self- producers. Animals - Heterotrophs: consumers.

Mitochondria Organellecellular respiration Organelle where cellular respiration takes place. Inner membrane Outer membrane Inner membrane space Matrix Cristae

Breakdown of Cellular Respiration Three main parts (reactions). Three main parts (reactions). 1. Glycolysis (splitting of sugar) a. cytosol, just outside of mitochondria.

Breakdown of Cellular Respiration 2. Krebs Cycle (Citric Acid Cycle) a. mitochondrial matrix 3. Electron Transport Chain (ETC a.. inner mitochondrial membrane.

1. Glycolysis Occurs in the cytosol just outside of mitochondria. Two phases: Two phases: A. Energy investment phase a. Preparatory phase B. Energy yielding phase a. Energy payoff phase

1. Glycolysis A. Energy Investment Phase: Glucose (6C) Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) 2 ATP - used 0 ATP - produced 0 NADH - produced 2ATP 2ADP +P C-C-C-C-C-C C-C-C

1. Glycolysis B. Energy Yielding Phase Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) Pyruvate (2 - 3C) (PYR) 0 ATP - used 4 ATP - produced 2 NADH - produced 4ATP 4ADP +P C-C-C GAP (PYR)

1. Glycolysis Total Net Yield Total Net Yield 2 - 3C-Pyruvate (PYR) 2 - ATP 2 - NADH

2. Krebs Cycle (Citric Acid Cycle) Location: Location: mitochondrial matrix. Acetyl CoA (2C) bonds to Oxalacetic acid (4C - OAA) to make Citrate (6C). It takes 2 turns of the krebs cycle to oxidize 1 glucose molecule. Mitochondrial Matrix

2. Krebs Cycle (Citric Acid Cycle) Krebs Cycle 1 Acetyl CoA (2C) 3 NAD + 3 NADH FAD FADH 2 ATP ADP +P (one turn) OAA (4C) Citrate (6C) 2 CO 2

2. Krebs Cycle (Citric Acid Cycle) Krebs Cycle 2 Acetyl CoA (2C) 6 NAD + 6 NADH 2 FAD 2 FADH 2 2 ATP 2 ADP +P (two turns) OAA (4C) Citrate (6C) 4 CO 2

2. Krebs Cycle (Citric Acid Cycle) 2 turns Total net yield (2 turns of krebs cycle) ATP (substrate-level phosphorylation) NADH FADH CO 2

3. Electron Transport Chain (ETC) and Oxidative Phosphorylation ( Chemiosmosis ) Location: Location: inner mitochondrial membrane. ETC Uses ETC and ATP Synthase (enzyme) to make ATP. ETC pumps H + (protons) across innermembrane (lowers pH in innermembrane space). Inner Mitochondrial Membrane

3. Electron Transport Chain (ETC) and Oxidative Phosphorylation ( Chemiosmosis ) diffusion The H+ then moves via diffusion through ATP Synthase to make ATP. cellular respiration All NADH and FADH 2 converted to ATP during this stage of cellular respiration. Each NADH converts to 3 ATP. Each FADH 2 converts to 2 ATP (enters the ETC at a lower level than NADH).

TOTAL ATP YIELD ATP – glycolysis and krebs cycle ATP - ETC 38 ATP - TOTAL YIELD ATP

Maximum ATP Yield for Cellular Respiration (Eukaryotes) 36 ATP (maximum per glucose) Glucose Glycolysis 2ATP 4ATP 6ATP 18ATP 4ATP 2ATP 2 ATP (substrate-level phosphorylation) 2NADH 6NADH Krebs Cycle 2FADH 2 2 ATP (substrate-level phosphorylation) 2 Pyruvate 2 Acetyl CoA ETC and Oxidative Phosphorylation Cytosol Mitochondria

Fermentation “NO Oxygen” (called anaerobic). Occurs in cytosol when “NO Oxygen” is present (called anaerobic). glycolysisfermentation Remember: glycolysis is part of fermentation. Two Types: Two Types: 1.Alcohol Fermentation 2. Lactic Acid Fermentation

Alcohol Fermentation Plants and Fungi  beer and wine Plants and Fungi  beer and wine glucose Glycolysis CCCCCCCCCCCCC CCCCCC 2 Pyruvic acid 2ATP 2ADP + 2 2NADH P 2 NAD + CCCC 2 Ethanol 2CO 2 released 2NADH 2 NAD +

Lactic Acid Fermentation Animals (pain in muscle after a workout). Animals (pain in muscle after a workout). 2 Lactic acid acid 2NADH 2 NAD + CCCCCC Glucose Glycolysis CCCCCC 2 Pyruvic acid 2ATP 2ADP + 2 2NADH P 2 NAD + CCCCCCCCCCCCC

Lactic Acid Fermentation End Products: Lactic acid fermentation End Products: Lactic acid fermentation 2 - ATP 2 - Lactic Acid molecules

Alcohol Fermentation End Products: Alcohol fermentation End Products: Alcohol fermentation 2 - ATP 2 - CO 2 2 – molecules of ethanol

Question: In addition to glucose, what other various food molecules are use in Cellular Respiration? In addition to glucose, what other various food molecules are use in Cellular Respiration?

Catabolism of Various Food Molecules Other organic molecules used for fuel. 1. Carbohydrates: polysaccharides 2. Fats: glycerol’s and fatty acids 3. Proteins: amino acids