Respiration

Cellular Respiration

RespirationRespiration uses chemical energy in the form of carbohydrates, lipids, or proteins, to produce ATP

Respiration suppliesthe energy for

muscle contraction

germination

cell division

chemical changes in cells

What is energy used for?10

3These are only a few examples. Every living process in living organisms needs energy from respiration

What Is ATP?ATP (Adenosine Tri-Phosphate)ATP is the short-term energy store of the cellATP is used by cells to perform their daily tasks

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How Do We Get Energy From ATP?By breaking the high- energy bonds between the last two phosphates in ATP

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ATP + H2O --- > ADP + Pi + Energy

ATPATP can be broken down into a molecule of ADP by removing one of the phosphate groupsThis releases energy

ADP can be remade into ATP later when the cell has food that can be broken down (i.e glucose)

Cell Respiration and Production of ATPThe breakdown of organic molecules (carbohydrates, lipids, proteins) releases energy

The energy released is used to build molecules of ATP

When a cell requires some energy it will break down ATP

RespirationRespiration is the release of energy from glucose or another organic chemical. The chemical energy in glucose can be used to provide the energy required for growth, repair and movement.

There are two types of respiration

Aerobic (requires oxygen)

Anaerobic (does not requires oxygen)

Mitochondria StructureSmooth outer Membrane

Folded inner membrane

Folds called Cristae

Space inside cristae called the Matrix

Mitochondria

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Aerobic RespirationRequires Oxygen

Main type of respiration that occurs in most situations in Plants and Animals

Involves complete breakdown of glucose back to CO2 and Water

C6H12O6 + 6O2 ----- > 6CO2 + 6H2O + 38 ATPs

Stages of Aerobic RespirationGlycolysisPreparation for Citric Acid Cycle (link raction)

The Krebs Cycle (Citric acid cycle)The Electron Transport Chain

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Where Does Aerobic Respiration Take Place?Glycolysis occurs in the CytoplasmLink reaction and Krebs Cycle on the matrixETC takes place in the inner membrane of the mitochondria

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GlycolysisGlycolysis is the first stage of cellular respiration

Occurs in cytoplasm

Glucose (6C) is broken down into 2 molecules of 3-carbon molecule pyruvateATP and NADH are produced as part of the process

The link reactionBefore the next stage can begin, pyruvate is transported inside the mitochondria.

The pyruvate releases one molecule of CO2.

It then combines with an enzyme called Coenzyme A to form the two-carbon molecule acetyl coenzyme A.

Krebs cycleOccurs in the matrix of the mitochondriaCyclical series of oxidation reactions that give off CO2 Turns twice per glucose moleculeProduces two ATP

Electron Transport ChainOccurs in the inner membrane of the mitochondriaElectrons are passed along the chain, from one protein to anotherElectrons drop in energy as they go down the chain and until they end up with O2.34 ATP are produced during this stage

Name of stageSite Key events1 2.3.4.

Name of stageSite Key events1 GlycosisCytoplasm2. Preparation for citric acid cycleMatrix of the mitochondria3. Citric acid cycle (Krebs cycle)Matrix of Mitochondria4. Electron transport chainInner membrane of mitochondria

Anaerobic RespirationFermentation

Releases energy from glucose without the presence of oxygen

There are 2 types of fermentation:AlcoholicLactic acid

ATP is still produced from glucose but not as efficiently as with Aerobic RespirationProduces only 2 ATP

Alcoholic fermentationOverall Equation:

Glucose 2 Ethanol + 2 CO2 + 2 ATPYeast produce wine and beer and cause bread to rise

Wine makingGrapes are crushed and the sugar they contain is fermented by yeasts to produce alcohol and carbon dioxide.The carbon dioxide usually escapes but if the wine is bottled before fermentation is complete, the carbon dioxide dissolves and escapes as bubble when the bottle is openedThis is the case with sparkling wines such as ChampagneDifferent varieties of grape produce different types of wine31

BakingIn baking, yeast is added to a mixture of flour and water, made into the form of a doughThe yeast first changes the flour starch into sugar and thenferments the sugar into alcohol and CO2The CO2 forms bubbles in the dough which cause it to expand (rise)When the dough is baked, the heat evaporates the alcohol but makes the trapped bubbles expand giving the bread a light texture35

The holes in the bread are made bythe carbon dioxidebubbles.This gives the bread a light texture

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Lactic Acid FermentationOverall Equation:

Glucose 2 Acid Lactic + 2 ATPBacteria produce yogurt and cheese.

In Muscle Cells- During exercise, the oxygen in the muscle tissue is decreased to an extent that aerobic respiration does not occur at a sufficient rate. Hence, there is a buildup of lactic acid and your muscles get tired

Factors Affecting RespirationKind of Cell or Tissue

Young and Developing cells usually have higher respiration ratesDeveloping and Ripening Fruit and Seeds, tooOlder Cells and Structural Cells Respire at Lower Rates

Factors Affecting RespirationTemperature

Respiration generally Has Higher Optimum and Maximum Temps than PS RxsCan Have Net Dry Matter Loss at High Temps where Respiration Exceeds PSTemp Refers to Temp Inside Plant or Animal Cell, not Air TempUsing Irrigation to Help Cool the Plant Can Keep the Plant in Net Gain Range

Factors Affecting RespirationOxygen

Low O2 Can Reduce Aerobic Respiration and Increase Anaerobic Respiration

Factors Affecting RespirationATP

Higher [ATP] Reduces Rate of RespirationFeedback InhibitionUsually Occurs when other Metabolic Processes Have Slowed or Stopped

Factors Affecting RespirationCO2

Higher CO2 Levels Reduce Rate of RespirationFeedback InhibitionSeldom Occurs except when O2 Levels Are LimitedFlooded, Compacted Soils