2.38-2.42 Respiration and Respiratory System

7/29/2019 2.38-2.42 Respiration and Respiratory System

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Respiration and the

Respiratory System

Form 4 Biology

Chapter 2.38-2.42


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What is Respiration?

The process of converting the chemical energy

stored in food to forms that organisms can use

glucose + oxygen water + carbon dioxide + energy

C6H12O6 + O2 H2O + CO2 + energy

Note: Respiration Breathing


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Adenosine triphosphate (ATP)

the energy currency of the cell


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ATP ADP (adenosine diphosphate)


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Energy is used in

Movement (the contraction of muscle

cells)

Maintenance of body temperature

Active transport

Cell division

Growth (synthesis of large molecules)


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RESPIRATION

AEROBIC

ANAEROBIC


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Anaerobic Respiration

Advantage

Does not require oxygen

DisadvantagesProduces less energy (glucose is not

completely broken down)

Produces toxic products (lactic acid, ethanol)


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Anaerobic Respiration

In Muscles

glucose lactic acid + energy

C6H12O6 2C3H6O3 In Yeasts

glucose ethanol + carbon dioxide

+energy

C6H12O6 2C2H5OH + 2CO2


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Muscle Cramps

Caused by the lactic acid build up in the muscles


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Muscle Cramps

Eventually the lactic acid is moved to

different parts of the body and oxidised

Lactic acid Pyruvate (pyruvate can beconverted to energy)

The oxygen needed to breakdown the

lactic acid is known asoxygen debt


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Oxygen Debt


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Experiments involving Respiration

Bleach is also used to surface-sterilised the peas

This experiment would show that heat is

produced during respiration


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Measuring the Rate of Respiration

This experiment proves that the organisms in flask

C releases CO2 The KOH is used to remove the CO2 in air

The HCO3- is used as an indicator to test the

presence of CO2


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Measuring the Rate of Respiration


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Human Respiratory System


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Epithelial Cells

Goblet cells produce

mucus to trap dust and

microbes

Cilia to carry trapped

dust and microbes

away from the lungs


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The pleural cavity isfilled with pleural fluid

The pleural fluidprevents the lung fromsticking into the thora


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Two pleural

membranes separatesthe thorax (chest wall)and the lungs

The space betweenthe two membranes iscalled the pleuralcavity


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Alveolusthe place where gas exchange takes place

(go to page 120 for the different properties)


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Ventilation/BreathingThe diaphragm The intercostal muscles

Composed of Internal and

External Intercostal muscles


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Inhalation

External intercostalMuscles Contracts

Muscles of theDiaphragm Contracts

Rib cage moves upand out

Diaphragm flattens

Increase Lung Volume Decrease in Pressure

Air is drawn in


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Exhalation

Internal intercostalMuscles Contracts

Muscles of theDiaphragm Relaxes

Rib cage fallsdownward and inward

Diaphragm becomesdome shaped

Decrease Lung Volume Increase in Pressure

Air is forced out


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Approximate Composition of Air

INHALED EXHALED

Oxygen 21 18

Carbon dioxide 0.04 3

Nitrogen 78 78

Water Vapour Variable Saturated

Temperature Variable 37C


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Spirogram


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Breathing and Exercises

Increase in the breathing rate

Increase in the tidal volume

more oxygen is

needed for

respiration tosupply muscles

with energy


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Smoking increases b.r.

Anxiety increase b.r.

Drugs increase/decrease br

Altitude increases b.r.

Weight increase/decrease b.r.

Environmental factors increase/decrease b.r.

Other factors affecting breathing rate

h


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Asthma

Muscles of the bronchi contract

Overproduction of mucus

Causes:

Allergens

Smoking

Emotional stress

Breathing in cold air


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Treatment:

Removal of the cause (like allergens)

bronchodilator

Asthma


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Effects of Smoking

It is hot It has a dehydrating effect

It contains harmful chemicals

TarCarbon monoxide

Sulphur dioxide

Nicotine

Arsenic

Free radicals

Irritates thelungs


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Tar causes cancer

irritant that causes coughing

Carbon monoxide

Oxygen depletion in the body

Sulphur dioxide

Irritates the respiratory tract


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Nicotine

Causes addiction

Increase blood pressure

Increase heart rate increases the demand for

O2

Arsenic

Arsenic poisoning headaches, drowsiness,

etc.

Free radicals

Damage proteins and DNA, ageing of cells

Eff t f S ki


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Effects of Smoking

Laryngitis Inflammation and infection

of the larynx

Husky voice and difficulty in

speaking

Bronchitis Inflammation and infection

of the bronchus

Caused by the destruction

of the cilia

Eff t f S ki


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Effects of Smoking

Emphysema

Destruction of the

air sacsLess surface area

for gas exchange

Eff t f S ki


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Effects of Smoking

Cancer

- uncontrolled

growth anddivision of cells

ff f k


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Effects of Smoking
http://www.youtube.com/watch?v=SaeJUCVEp2s

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2.38-2.42 Respiration and Respiratory System