36007811 Respiration Chp 7 Biology Form 4

8/3/2019 36007811 Respiration Chp 7 Biology Form 4

1/24

RESPIRATION7.1 THE RESPIRATORY PROCESS IN ENERGY

PRODUCTION


2/24

CELL RESPIRATION

All organism require energy to carry out all livingprocesses

Energy is required for various processes whichoccur in the cell such as:

Cell division for growth

Formation of gamete for reproduction

Transmitting nerve impulses for response andcoordination

Contraction of muscles for movement

Synthesis of proteins, hormones, lipids and enzymes


3/24

CELLRESPIRATION

Respiration is the process in which nutrients areconverted into useful energy in a cell

The main substrate for respiration is glucose

Glucose is obtained from: Digestion of carbohydrates in humans and animals

The process of photosynthesis in plants

Respiration at the cellular level is known as cellularrespiration

The process occurs in the mitochondria andcytoplasm of cells

Respiration involves a series of reactions controlledby enzymes


4/24

TYPEOF RESPIRATION

There are two types of respiration in the cell

Aerobic respiration

Anaerobic respiration


5/24

AEROBIC RESPIRATION

Aerobic respiration also known as 'oxidativemetabolism

Aerobic respiration is the breaking down ofglucose in the presence of oxygen to releasechemical energy

Oxygen is required to oxidise the glucose toproduce carbon dioxide, water and energy (ATP)

In aerobic respiration, the glucose is completelyoxidised
http://en.wikipedia.org/wiki/Oxidativehttp://en.wikipedia.org/wiki/Metabolismhttp://en.wikipedia.org/wiki/Metabolismhttp://en.wikipedia.org/wiki/Oxidative


6/24

AEROBIC RESPIRATION

Occurs in the mitochondria and cytoplasm ofcells

The reactions occurs slowly and in stagescontrolled by enzymes

Some of the chemical energy released is changedto heat energy while the rest of the chemical energyis stored in the form of adenosine triphosphate(ATP), a carrier of chemical energy

ATP can be regenerated by combining inorganicphosphate (P) to adenosine diphosphate (ADP)


7/24

When body cells need energy, ATP molecules will behydrolysed to yield energy, a molecule of ADP and aninorganic phosphate

During aerobic respiration, at least 38 molecules ofATP or 2898 kJ of energy is released

Aerobic respiration can be represented by the followingequation:

The oxygen for aerobic respiration comes from inhaledair while the carbon dioxide released is removed duringexhalation

ATP ADP + P + energy

Glucose + oxygen carbon dioxide + water + 38 ATP/ 2898 kJ

C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP/ 2898 kJ


8/24

ANAEROBIC RESPIRATION

Refers to the special type of respiration, whichtakes place without oxygen

Anaerobic respiration is the process of oxidation ofmolecules in the absence of oxygen

Anaerobic respiration is synonymous withfermentation

Glucose is not completely broken down. Not allthe energy in glucose is released

Occurs in the cytoplasm of the cells


9/24

ANAEROBIC RESPIRATIONIN HUMANMUSCLES

Occurs in human muscles during vigorous activities

During vigorous activities, oxygen need to betransported fast enough to the muscles for rapid cellrespiration

This will enable the release of sufficient energy for thevigorous muscle activity

The breathing rate and heart rate are increased tosupply more oxygen quickly to the muscles for rapid

muscular contraction However, the supply of oxygen to the muscles is still

insufficient and the muscles have to carry outanaerobic respiration to release energy


10/24

In the muscles cells, glucose is broken down in theabsence of oxygen to form lactic acid and energy formuscle contraction

Lactic acid accumulates in the muscles causingmuscular ache

An oxygen debt incurred because the maximum rate ofoxygen used is less than the oxygen supplied

Oxygen is required to pay off the oxygen debt Rapid breathing continues after the vigorous exercise

obtain sufficient oxygen

Glucose Lactic acid + 2 ATP/ 150 kJ

C6H12O6 2C3H6O3 + 2 ATP/ 150 kJ


11/24

Oxygen oxidises the lactic acid to carbon dioxide,water and energy

When all lactic acid is oxidised, the oxygen debt issaid to be paid

Oxidation of lactic acid mainly occurs in the liver

Some of the lactic acid is oxidised to produce energy

The remaining is converted to glucose and thenglycogen which is then stored in the muscle cells

Lactic acid carbon dioxide + water + energyoxygen


12/24

ANAEROBIC RESPIRATIONIN YEAST

Yeast carries out both aerobic respiration andanaerobic respiration

Anaerobic respiration in yeast cells is calledfermentation

During fermentation, yeast secretes the enzymezymase which hydrolyses glucose in the absence ofoxygen to form ethanol, carbon dioxide and 2 ATP

Glucose ethanol + carbon dioxide + energy

C6H12O6 2C5H5OH + 2CO2 + 2 ATP/ 210 kJ

Enzymezymase

Enzymezymase


13/24

The enzyme zymase secreted by the yeast speed upthe fermentation process

In the fermentation process, only a small amount ofenergy is released

A large amount of energy is still stored in the ethanolas chemical energy

This is because the glucose is not completely brokendown

The products of fermentation such as carbon dioxideis used as raising agent in baking bread whileethanol is used to produce alcoholic drinks such as

wine


14/24

COMPARISONBETWEEN AEROBICANDANAEROBICRESPIRATION

Aerobic respiration Anaerobic respirationOccurs in the _________ of oxygen Occurs in the ____________ of

oxygen

Releases _________ amount ofenergy (___ molecules of ATP or

______ kJ)

Releases ________ energy ( ____molecules of ATP or ____ kJ(muscle cells) _____ kJ (yeast)

Produces ____________ and__________

Produces ____________ (humanmuscles) or ________________(yeast)

Glucose is _______________broken down

Glucose is ___________________broken down

Occurs in the _________________and _____________________

Occurs in the __________________only


15/24

RESPIRATIONINFISH


16/24


17/24

AMPHIBIANS


18/24

BRAIN SENSORTHECHANGESOF CO2AND O2

How???


19/24

Breathing is clearly an involuntary process (you don'thave to think about it), and like many involuntaryprocesses (such as heart rate)

it is controlled by a region of the brain called themedulla.

The medulla and its nerves are part of the autonomicnervous system (i.e. involuntary). The region of themedulla that controls breathing is called the

respiratory centre. The main centres are theapneustic centre, which enhances inspiration, and thepneumotaxic centre, which terminates inspiration.


20/24

The respiratory center transmits regular nerveimpulses to the diaphragm and intercostal musclesto cause inhalation. Stretch receptors in the alveoliand bronchioles detect inhalation and send

inhibitory signals to the respiratory center to causeexhalation. This negative feedback system incontinuous and prevents damage to the lungs.


21/24

Ventilation is also under voluntary control from thecortex, the voluntary part of the brain. This allowsyou to hold your breath or blow out candles, but itcan be overruled by the autonomic system in the

event of danger. For example if you hold yourbreath for a long time, the carbon dioxideconcentration in the blood increases so much thatthe respiratory centre forces you to gasp and take a

breath.


22/24

IMPORTANCEOFMAINTAININGAHEALTHYRESPIRATORYSYSTEM


23/24

http://www.youtube.com/watch?v=rNTEOCFmOIQ

(fish breath)

http://www.youtube.com/watch?v=Nfojq4ikHH0

(Frog breath)

http://www.youtube.com/watch?v=HV60yTvy3Mk

(insect reapiration)

http://www.youtube.com/watch?v=IlmgFYmbAUg&feature=related(plant respiration)
http://www.youtube.com/watch?v=rNTEOCFmOIQ(fishhttp://www.youtube.com/watch?v=rNTEOCFmOIQ(fishhttp://www.youtube.com/watch?v=Nfojq4ikHH0http://www.youtube.com/watch?v=HV60yTvy3Mkhttp://www.youtube.com/watch?v=IlmgFYmbAUg&feature=related(planthttp://www.youtube.com/watch?v=IlmgFYmbAUg&feature=related(planthttp://www.youtube.com/watch?v=IlmgFYmbAUg&feature=related(planthttp://www.youtube.com/watch?v=IlmgFYmbAUg&feature=related(planthttp://www.youtube.com/watch?v=HV60yTvy3Mkhttp://www.youtube.com/watch?v=Nfojq4ikHH0http://www.youtube.com/watch?v=rNTEOCFmOIQ(fishhttp://www.youtube.com/watch?v=rNTEOCFmOIQ(fishhttp://www.youtube.com/watch?v=rNTEOCFmOIQ(fish


24/24

http://www.youtube.com/watch?v=HiT621PrrO0&feature=related

Human breathing system

http://www.youtube.com/watch?v=RWC8BRCuTtg&feature=related
http://www.youtube.com/watch?v=HiT621PrrO0&feature=relatedhttp://www.youtube.com/watch?v=HiT621PrrO0&feature=relatedhttp://www.youtube.com/watch?v=HiT621PrrO0&feature=relatedhttp://www.youtube.com/watch?v=HiT621PrrO0&feature=related

Documents

36007811 Respiration Chp 7 Biology Form 4