Cellular Cellular RespirationRespiration

THE GUMMY BEAR VIDEOTHE GUMMY BEAR VIDEOSo exactly how much energy does photosynthesis capture?So exactly how much energy does photosynthesis capture?

Cell EnergyCell Energy

Energy comes in many forms, including light, Energy comes in many forms, including light, heat, and electricity. It is also stored in things heat, and electricity. It is also stored in things like food and batteries.like food and batteries.

Energy cannot be created or destroyed, but it Energy cannot be created or destroyed, but it can change formscan change forms

Cells use the energy in food to charge special Cells use the energy in food to charge special cell batteries called ATPcell batteries called ATP

Adenosine triphosphate (ATP)Adenosine triphosphate (ATP)

ATP is the ATP is the chemical compound chemical compound that cells that cells use use for for energyenergy

Modified nucleic acidModified nucleic acid

made up ofmade up of::

- - adenineadenine (N containing compound) (N containing compound)

- - riboseribose (5 C sugar) (5 C sugar)

- - 3 phosphate groups3 phosphate groups

ATPATP

Reminder: cells use ATP for Reminder: cells use ATP for active transportactive transport, , maintaining homeostasismaintaining homeostasis, and , and cellular cellular movementmovement

Adenosine diphosphate Adenosine diphosphate (ADP)(ADP)

ADP is a “dead battery” formed when a ADP is a “dead battery” formed when a “P” is broken off the ATP to release “P” is broken off the ATP to release energyenergy. ADP can be . ADP can be recharged by using recharged by using carbohydrate energy to reconnect the carbohydrate energy to reconnect the lost lost PP. .

contains:contains:

- adenine (N containing compound)- adenine (N containing compound)

- ribose (5 C sugar)- ribose (5 C sugar)

- 2 phosphate groups- 2 phosphate groups

ADP vs. ATPADP vs. ATPThe process of recharging ATP using carbohydrates is called Respirationa single carbohydrate glucose (sugar) contains enough energy to recharge 90 ATP.

Overview of Cellular RespirationOverview of Cellular Respiration

Cellular respiration is the process that releases Cellular respiration is the process that releases energy from glucose (best when in the energy from glucose (best when in the presence of oxygen at the mitochondria) to presence of oxygen at the mitochondria) to recharge ATP. recharge ATP.

EquationEquation::

6O6O22 + C + C66HH1212OO66 → 6CO→ 6CO22 + 6H + 6H22O + energy (ATP)O + energy (ATP)

oxygen + glucose → carbon dioxide + water + energyoxygen + glucose → carbon dioxide + water + energy

MEMORIZE THIS! MEMORIZE THIS!

(Does it look familiar?!)(Does it look familiar?!)

YES!YES!The equation for The equation for cellular cellular respirationrespiration is the is the exact exact opposite opposite ofof that of that of photosynthesis!photosynthesis!

Photosynthesis:Photosynthesis:

6CO6CO22 + 6H + 6H22O + energy → O + energy → 6O6O22 + C + C66HH1212OO66

Respiration:Respiration:

6O6O22 + C + C66HH1212OO66 → 6CO→ 6CO22 + 6H + 6H22O + energyO + energy

Photosynthesis and Respiration together make a Photosynthesis and Respiration together make a cycle called the Carbon cycle. cycle called the Carbon cycle.

RespirationRespirationALL cells (including plants) undergo respiration ALL cells (including plants) undergo respiration in order to recharge their ATPin order to recharge their ATP

Respiration reverses the work of Respiration reverses the work of photosynthesis. It uses oxygen to break down a photosynthesis. It uses oxygen to break down a sugar, releasing CO2 and water as wastesugar, releasing CO2 and water as waste

Two types of respirationTwo types of respiration– Aerobic (requires oxygen, takes place in the Aerobic (requires oxygen, takes place in the

cytoplasm and mitochondria, creates 34-36 cytoplasm and mitochondria, creates 34-36 ATP per glucose)ATP per glucose)

– Anaerobic (no oxygen needed, takes place in Anaerobic (no oxygen needed, takes place in the cytoplasm, creates only 2 ATP per the cytoplasm, creates only 2 ATP per glucose, also called fermentation)glucose, also called fermentation)

Overview of Cellular RespirationOverview of Cellular Respiration

Three main stagesThree main stages ((Aerobic requires all three Aerobic requires all three stages, stages, anaerobic only anaerobic only requires requires stage onestage one))

• 1. 1. glycolysis (in the cytoplasm): break glucose glycolysis (in the cytoplasm): break glucose in half in half and charge 2 ATP; no oxygen and charge 2 ATP; no oxygen neededneeded

• 2. 2. Krebs Cycle (in the mitochondria): further Krebs Cycle (in the mitochondria): further breakbreak down the pieces of down the pieces of glucose and release glucose and release energy for ETC; requires oxygenenergy for ETC; requires oxygen

• 3. 3. Electron Transport Chain (in the Electron Transport Chain (in the mitochondria): use the energy from the Krebs mitochondria): use the energy from the Krebs Cycle Cycle to charge an additional 32-34 ATP; to charge an additional 32-34 ATP; requires oxygenrequires oxygen

Overview of Cellular RespirationOverview of Cellular Respiration

Gross vs Net ATPGross vs Net ATPGlycolysisGlycolysis (stage one) occurs first. It (stage one) occurs first. It does does not require oxygen, but it does require a not require oxygen, but it does require a little ATPlittle ATP. Glycolysis . Glycolysis uses 2 ATP to make uses 2 ATP to make 4 ATP4 ATP, so the , so the NET production = 2 ATPNET production = 2 ATP

Glycolysis NotesGlycolysis NotesThis process is so fast that thousands of ATPs This process is so fast that thousands of ATPs can be produced in a few milliseconds! can be produced in a few milliseconds!

Some small cells that don’t need a lot of energy Some small cells that don’t need a lot of energy can survive only through glycolysis (ex: can survive only through glycolysis (ex: bacteria, yeast)bacteria, yeast). .

After GlycolysisAfter GlycolysisIf oxygen is presentIf oxygen is present, then the , then the products of glycolysis products of glycolysis move on to move on to the mitochondria for the mitochondria for stages 2 stages 2 and 3and 3. There they will be further . There they will be further broken down to create MUCH broken down to create MUCH more ATP energy. more ATP energy.

What if oxygen is NOT present?What if oxygen is NOT present?

If there is no oxygen, anaerobic If there is no oxygen, anaerobic respirationrespiration (AKA fermentation) (AKA fermentation) is is used to keep glycolysis going used to keep glycolysis going (2 ATP (2 ATP is better than no ATP!) is better than no ATP!)

Types of Anaerobic FermentationTypes of Anaerobic Fermentation1. Alcoholic Fermentation: used by yeast; 1. Alcoholic Fermentation: used by yeast; produces alcohol and COproduces alcohol and CO22 to keep glycolysis to keep glycolysis goinggoing

2. Lactic Acid Fermentation: used by 2. Lactic Acid Fermentation: used by multicellular animals: produces lactic acidmulticellular animals: produces lactic acid to to keep glycolysis going; keep glycolysis going; reason for burning reason for burning muscles when working outmuscles when working out

Anaerobic Respiration ReminderAnaerobic Respiration Reminder

The purpose of both alcoholic and lactic The purpose of both alcoholic and lactic acid fermentation is to keep glycolysis acid fermentation is to keep glycolysis going. Anaerobic respiration of any type going. Anaerobic respiration of any type only makes 2 ATP per glucose. only makes 2 ATP per glucose.

ATP TotalsATP TotalsGlycolysis alone Glycolysis alone (anaerobic (anaerobic respirationrespiration/Stage One /Stage One only) only) produces produces 2 ATP2 ATP molecules per glucosemolecules per glucose

With With OO22, Aerobic Respiration , Aerobic Respiration (all three stages) (all three stages) produces produces 34-36 ATP34-36 ATP molecules per molecules per glucose!glucose!

The remainder of the The remainder of the energy in glucose is energy in glucose is converted to heat which converted to heat which helps maintain body helps maintain body temperature.temperature.

Comparing Photosynthesis & Cellular RespirationComparing Photosynthesis & Cellular Respiration

energy energy

Photosynthesis Cellular Respiration

function energy capture energy releases

location chloroplasts mitochondria

reactants CO2 and H2O C6H12O6 and O2

products C6H12O6 and O2 CO2 and H2O

equation

6CO2 + 6H2O → C6H12O6 + 6O2 C6H12O6 + 6O2 → 6CO2 + 6H2O