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CHAPTER 7 :CHAPTER 7 :

RESPIRATIONRESPIRATION

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State that all living processes require energyState that all living processes require energy Identify the main substrate for producing energyIdentify the main substrate for producing energy State the two types of respirationState the two types of respiration Explain what cell respiration isExplain what cell respiration is Explain the energy production from glucose Explain the energy production from glucose

during the process of aerobic respirationduring the process of aerobic respiration State the conditions leading to anaerobic State the conditions leading to anaerobic

respiration in cellsrespiration in cells Explain the process of anaerobic respiration in Explain the process of anaerobic respiration in

human muscleshuman muscles Write the chemical equations for aerobic & Write the chemical equations for aerobic &

anaerobic respirationanaerobic respiration Compare & contrast aerobic respiration with Compare & contrast aerobic respiration with

anaerobic respirationanaerobic respiration

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All organisms require energy to carry out All organisms require energy to carry out all living processesall living processes growth (cell growth (cell division), reproduction (meiosis), response division), reproduction (meiosis), response (transmitting impulses), movement (transmitting impulses), movement (contraction of muscle), breathing, (contraction of muscle), breathing, digestion & excretion (synthesis of digestion & excretion (synthesis of proteins, hormones, lipids & enzymes)proteins, hormones, lipids & enzymes)

RESPIRATIONRESPIRATION : : the metabolic process the metabolic process in which organic molecules broken in which organic molecules broken down to simpler products with the down to simpler products with the release of chemical energy for other release of chemical energy for other living processesliving processes..

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Occurs in Occurs in two stagetwo stage : : External respirationExternal respiration – a mechanical process – a mechanical process

that maintains a continuous exchange of gases that maintains a continuous exchange of gases between the respiratory surfaces of an organisms between the respiratory surfaces of an organisms & its environment& its environment

Internal respirationInternal respiration (cellular respiration) – the (cellular respiration) – the biochemical process in which energy is made biochemical process in which energy is made available to all living cellsavailable to all living cells

The main substrate : The main substrate : glucoseglucose (obtain from (obtain from digestion of carbohydrates & photosynthesis)digestion of carbohydrates & photosynthesis)

Occurs in Occurs in mitochondria & cytoplasmmitochondria & cytoplasm of cells of cells

Involves a series of reactions Involves a series of reactions controlled by controlled by enzymesenzymes

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TYPES OF RESPIRATIONTYPES OF RESPIRATION AEROBIC RESPIRATIONAEROBIC RESPIRATION

ANAEROBIC RESPIRATIONANAEROBIC RESPIRATION

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AEROBIC RESPIRATIONAEROBIC RESPIRATION The breaking down of glucose The breaking down of glucose in thein the

presence of oxygen presence of oxygen toto release release chemical energychemical energy

OxygenOxygen is required to oxidise the is required to oxidise the glucose to produce COglucose to produce CO22, H, H22O & energyO & energy

The glucose is The glucose is completely oxidisedcompletely oxidised to to release all the chemical energy in the release all the chemical energy in the glucoseglucose

Occurs in mitochondria & cytoplasm Occurs in mitochondria & cytoplasm of cellsof cells

SlowlySlowly occurs & in occurs & in stagesstages controlled controlled by enzymes.by enzymes.

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The energy is released in stages & in small The energy is released in stages & in small amountsamounts

Some chemical energy released in Some chemical energy released in changed to heat energy while the rest of changed to heat energy while the rest of the chemical energy released is stored in a the chemical energy released is stored in a form of form of ATPATP, a carrier of chemical energy, a carrier of chemical energy

ATP can e regenerated by combining ATP can e regenerated by combining inorganic phosphate (P) to ADP using the inorganic phosphate (P) to ADP using the chemical energy obtained from the chemical energy obtained from the oxidation of foodoxidation of food

ATP ATP ADP + P + energy ADP + P + energy

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When body cells need energy, When body cells need energy, ATP ATP molecules will be hydrolysedmolecules will be hydrolysed to yield to yield energy, a molecule energy & an energy, a molecule energy & an inorganic phosphateinorganic phosphate

Energy from ATP can be used to carry Energy from ATP can be used to carry out biological processout biological process

Glucose + oxygen Glucose + oxygen carbon dioxide + water + carbon dioxide + water + energyenergy

CC66HH1212OO66 + 6O + 6O22 6CO 6CO22 + 6H + 6H220 + 38 ATP 0 + 38 ATP (2898 kJ)(2898 kJ)

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ANAEROBIC RESPIRATION A type of cell respiration which occurs A type of cell respiration which occurs

in the absence of oxygen to release in the absence of oxygen to release energyenergy

Glucose is not completely broken Glucose is not completely broken down down not all energy in glucose is not all energy in glucose is releasedreleased

Some of the energy in glucose is Some of the energy in glucose is stored in the product of anaerobic stored in the product of anaerobic respiration respiration 2 ATP is released 2 ATP is released

Occurs in cytoplasmOccurs in cytoplasm

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ANAEROBIC RESPIRATION IN HUMAN ANAEROBIC RESPIRATION IN HUMAN MUSCLESMUSCLES

Occurs during vigorous exercise @ vigorous Occurs during vigorous exercise @ vigorous activities (100m sprint).activities (100m sprint).

Oxygen need to be transported fast enough to Oxygen need to be transported fast enough to the muscles for rapid cell respiration. Will the muscles for rapid cell respiration. Will enable the release of sufficient energy for the enable the release of sufficient energy for the vigorous muscle activity.vigorous muscle activity.

The breathing rate & heart rate are increased The breathing rate & heart rate are increased to supply more oxygen quickly to the muscles to supply more oxygen quickly to the muscles for rapid muscular contractionfor rapid muscular contraction

Still insufficient Still insufficient have to carry out anaerobic have to carry out anaerobic respiration to release energyrespiration to release energy

CC66HH1212OO66 2C 2C33 H H66OO33 + 2 ATP (150 kJ) + 2 ATP (150 kJ)Glucose Lactic acidGlucose Lactic acid Energy Energy

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Lactic acid accumulates in the muscles Lactic acid accumulates in the muscles causing muscular ache (cramp)causing muscular ache (cramp)

An OXYGEN DEBT incurred because the An OXYGEN DEBT incurred because the maximum rate of oxygen used is less maximum rate of oxygen used is less than the oxygen suppliedthan the oxygen supplied

Oxygen is pay off by rapid breathing Oxygen is pay off by rapid breathing continues after the vigorous activity to continues after the vigorous activity to obtain sufficient oxygenobtain sufficient oxygen

The oxygen will break down the lactic The oxygen will break down the lactic acid to carbon dioxide, water & energyacid to carbon dioxide, water & energy

oxygenoxygen

Lactic acid Lactic acid carbon dioxide + water + carbon dioxide + water + energyenergy

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ANAEROBIC RESPIRATION IN ANAEROBIC RESPIRATION IN YEASTYEAST

Yeast carries out both aerobic & anaerobic Yeast carries out both aerobic & anaerobic respirationrespiration

Anaerobic respiration in yeast cells called Anaerobic respiration in yeast cells called fermentationfermentation..

Yeast secretes the enzyme zymase which Yeast secretes the enzyme zymase which hydrolyses glucose in the absence of oxygen to hydrolyses glucose in the absence of oxygen to form ethanol, carbon dioxide & energyform ethanol, carbon dioxide & energy

CC66HH1212OO66 2C2C22HH55OH + 2COOH + 2CO22 + 210 kJ + 210 kJ

Glucose Glucose EthanolEthanol carbon dioxide energy carbon dioxide energy

The enzyme zymase secreted by the yeast speeds The enzyme zymase secreted by the yeast speeds up the fermentation process up the fermentation process

The product of fermentation as CO2 is used as a The product of fermentation as CO2 is used as a raising agent in aking bread while ethanol is used to raising agent in aking bread while ethanol is used to produce alcoholic drinks such as wine.produce alcoholic drinks such as wine.

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COMPARISON BETWEEN AEROBIC COMPARISON BETWEEN AEROBIC RESPIRATION & ANAEROBIC RESPIRATION & ANAEROBIC

RESPIRATIONRESPIRATION AEROBIC AEROBIC

RESPIRATIONRESPIRATIONANAEROBIC ANAEROBIC

RESPIRATIONRESPIRATION

Presence of oxygenPresence of oxygen Absence of oxygenAbsence of oxygen

Large amount of energy Large amount of energy (38 ATP @ 2898 kJ)(38 ATP @ 2898 kJ)

Less energy (2 ATP @ 150 Less energy (2 ATP @ 150 kJ/210 kJkJ/210 kJ

Produce CO2 & waterProduce CO2 & water Produce lactic acid or Produce lactic acid or ethanolethanol

Completely broken down Completely broken down of glucoseof glucose

Glucose not completely Glucose not completely broken downbroken down