Respiration 3 e_part 1

The Breath of Life

Respiration

Lesson OutLine

Aerobic Vs Anaerobic Respiration

Anatomy of the Respiratory

System

Physiology of the Respiratory System

Smoking and Lung Diseases

RESPIRATION

1. Aerobic Respiration

2. Anaerobic Respiration

1. Mechanism of Breathing

Learning ObjectivesBy the end of the lesson, you should be able to:

i) Define aerobic respiration as the release of a relatively large amount of energy by the breakdown of food substances in the presence of oxygen

ii) State the equation (in words and symbols) for aerobic respiration

iii) Define anaerobic respiration as the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen

iv) State the equation (in words only) for anaerobic respiration in humans

Energy Makes the World Goes Round

Everything in the world works only because they could use energy.

and Life is no exception…

Burning Food… …

Early Earth is a tough neighbourhood

Earth was borne out of the solar nebula without oxygen.

Why is this so?

If there was no oxygen, how did life begin?

A Thirst for Energy -An Ancient Battle

Sulphur Bacteria Life didn’t really need oxygen, but there is one thing that all life needs… and that is Energy.

The battle for energy is an ancient one, and even today, people war with one another for sources of energy such as fossil fuel.Methanogens

ENERGY

How does body convert

energy stored in food

energy for body use?

Respiration

Definition: Respiration is the oxidation of food substances (glucose)

with the release of energy in living cells

Respiration is a characteristic of life since all living things require energy for essential activities

PG 194

2 Types of : Aerobic and Anaerobic respiration

Aerobic and Anaerobic Respiration

Aerobic Respiration

Anaerobic Respiration

RESPIRATION

Alcoholic Fermentation

Lactic Acid Production

Aerobic Respiration

C6H12O6 + 6O2 6CO2 + 6H2O +

energy

glucose oxygen carbon waterdioxide

Alcoholic Fermentation

Lactic Acid Production

C6H12O6 2C2H5OH + 2CO2 + energy

glucose ethanol carbondioxide

• Occurs in yeast cells.

C6H12O6 2C3H6O3 + energy

glucose lacticacid

• Occurs in muscle cells.• Leads to fatigue.

Aerobic and Anaerobic Respiration

• Those who uses oxygen to oxidize food:

• Those who do not use oxygen to oxidize food:

Aerobic Respiration• is the oxidation of glucose in the presence of oxygen with the

release of a large amount of energy.• Carbon dioxide and water are released as waste products.

Anaerobic Respirationis the breakdown of food molecules in the absence of oxygen.

Anaerobic respiration releases less energy than aerobic respiration.

Aerobic RespirationGlucose + oxygen carbon dioxide + water + release large amount of energy

• Catalysed by enzymes • Aerobic respiration generate heat, which is circulated around

the body to maintain a constant optimum body temperature• Many processes in living organisms require energy:

• Active transport• Muscular contractions• Catabolism (Breaking up of complex molecules)• Anabolism (Building up of complex molecules)• Cell division• Transmission of nerve impulses

Anaerobic respiration

Definition:Anaerobic respiration is the release of a relatively small amount of energy by the breakdown of food substances in absence of oxygen

• Glucose is only partially broken down. • The ethanol/lactic acid produced still contain much

energy. • Hence only a small amount of energy is released in the

process

Glucose Carbon dioxide + ethanol + little energyGlucose Lactic acid + little energy

Pg 195-196

Some microbes living in the mud… low oxygen level …

Respire ananerobically!

Yeast!Glucose (with yeast)

Carbon dioxide + ethanol + little energy

Alcoholic FermentationGlucose (with yeast)



Anaerobic RespirationGlucose (with baker’s yeast)


Glucose Lactic acid + energy

Anaerobic respiration in humans!Highly intensive exercise

Production of lactic acidIn Muscles• During strenuous exercise, the breathing rate

and heartbeat will be increased so that oxygen can be brought faster to muscles

• There is a limit to rate of breathing and heartbeat

• Extra energy for strenuous exercise is thus produced by anaerobic respiration in muscles

PG 196

What happens when you need more energy

but not enough oxygen?

PG 196

Anaerobic Respiration in the Muscles

1. Vigorous muscle movement increase rate of aerobic respiration (oxidation of glucose) to release more energy.

Prolonged muscular contraction

2. Insufficient oxygen available leads to muscle cells undergoing anaerobic respiration to release even more energy.

3. Lactic acid accumulates in muscles causing fatigue, muscle pain, cramps.

4. Muscle cells incur oxygen debt.

PG 196

During recovery…

1. Breathing rate continues to be fast.

2. Provides oxygen to repay oxygen debt.

3. Oxygen can break down lactic acid:

a. to produce energy

b. Convert lactic acid back into glucose

4. Oxygen debt is repaid when lactic acid is used up.

PG 196-197 “Repaying” oxygen debt

Oxygen debt

The amount of oxygen needed to dispose of the lactic acid is called oxygen debtThe time taken to remove all the lactic acid is called the recovery period

PG 196-197

Energy needed for vigorous exercise

Glucose + oxygen Carbon dioxide + water + energy

Glucose + Oxygen Lactic acid + little energy

Total amount of energy needed for vigorous muscular

contractions

PG 196

Aerobic respiration


Investigation 10.3 (page 199)

3 To allow oxygen to diffuse in and carbon dioxide to diffuse out of the flask.5 The reading should be higher than room temperature for flask A. Germinating seeds release heat during respiration.6 Advantages are:

a) fewer seeds need to be used.b) the thermometers need not be inserted too

deeply into the flask so that they can be read more easily.

Test Yourself (Page 200)Test Yourself! (page 200)

1(a) The solution would turn yellow. The snail would respire and give out carbon dioxide. Carbon dioxide would dissolve in the water to form carbonic acid.

(b) The solution would turn purple. The green plant would photo synthesise and remove carbon dioxide from the solution.

(c) Any carbon dioxide released by the snail is used up by the plant for photosynthesis. The rate of photosynthesis = the rate of respiration in both organisms.

(d) No. It serves as a control.

23(a) Rate of oxygen uptake (b) To absorb carbon dioxide (c) To the left (d) Rate of oxygen uptake = (100 X ( X 12)/2) mm2/minute4 Refer to Investigation 10.2 (page 199).

2(a) The set-up would be similar to that in question 3, if the boiling tube in question 3 were replaced by the conical flask containing germinating bean seeds. The tube of sodium hydroxide could be suspended within the flask.

(b) The sodium hydroxide would absorb any carbon dioxide produced as a result of respiration, therefore any change in the volume of air inside the flask would be due to the uptake of oxygen by the seeds. As

oxygen is taken up by the seeds, the droplet of coloured water would move along the capillary tube. The position of the coloured droplet would indicate the volume of oxygen taken in. Readings would be taken at suitable time intervals, e.g. 5 s, 10 s, 15 s and then averaged to

find out the rate of oxygen uptake by the germinating seeds.(c) Changes in the temperature of the surroundings may affect the rate of

oxygen uptake by the germinating bean seeds. The temperature of the surroundings should be kept constant (set-up should be placed in a warm environment as the seeds are germinating).

How do organisms obtain oxygen for aerobic respiration?

Gaseous exchange: Exchange of gases between an organism and the environment

How do human carry out gaseous exchange?

Learning ObjectivesBy the end of the lesson, you should be able to:

i) identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries

ii) state the characteristics of, and describe the role of, the exchange surface of the alveoli in gaseous exchange

iii) describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing

Adaptations to Land Living

• Oxygen must be dissolved before it can be absorbed.

• As such all respiratory surfaces must be moist.

• This is no problem for an aquatic animal such as a fish.

• What about terrestrial animals?

Respiratory surfacesThe surface through which respiratory gases are exchanged

between the organism’s internal and external environment

The actual design of the surface depends on factors like habitat, size and activity of organism

E.g. Lungs –mammals, birds, reptiles, amphibiansGills –Fish, amphibiansTracheoles – ArthropodsLeaf cells – PlantsBody covering- small animals (amoeba, earthworm)

Adaptations to Land Living

• As the first vertebrate animal venture onto land, obtaining oxygen becomes a gargantuan task.

• There is little moisture for the respiratory surface to function properly.

Respiratory Surfaces

• Moist respiratory surface (air sacs are located in body cavity)

• Allow animal to dissolve oxygen from the air directly into the moist respiratory surfaces.

Characteristics of Respiratory Surfaces

1. Moist surface for oxygen to dissolve

2. Large surface area to volume ratio for gasesous exchange

3. Thin-walled ensure a faster rate of diffusion/exchange of gases

4. Close association with circulatory system:

Richly supplied with blood capillaries (continuous blood flow maintains steep diffusion gradient)

Rate of diffusion of gases across respiratory surfaces is increased

Anatomy of the Human Respiratory System

Anatomy of the Human Respiratory System

May 2, 2023 Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd.

atmosphere

Path of Air Through the Respiratory System


atmosphere

external nostril

external nostril



atmosphere

external nostril

nasal passages (lined with

moist mucus membrane)

external nostril

nasal passages


Nasal Passages (Nasal cavity)

Lined with moist mucus membrane.

Advantages of breathing through nose:

1. Hairs and moist mucous membrane lining alls of external nostrils filter air, trap dust and foreign particles

2. Blood capillaries and mucus warm and moisten air respectively before entry into lungs.

3. Sensory cells(small receptor cells) in mucous membrane may detect harmful chemicals in the air (sense of smell)

atmosphere

external nostril

nasal passages

Pharynx (throat)

external nostrilpharynx

nasal passages


Located behind the mouth cavity, air passes through it on the way to glottis


atmosphere

external nostril

nasal passages

pharynx

Larynx (Adam’s Apple)

external nostril

larynx

pharynxnasal passages


Situated at top of trachea Has cartilage to keep it openIs the voicebox with vocal chords stretched across it

May 2, 2023

atmosphere

external nostril

nasal passages

pharynx

larynx

Trachea (Windpipe)

external nostril

trachealarynx

pharynxnasal passages


-A long tube supported by C-shaped rings of cartilage to keep it open.- Inner wall lined with cilia and mucous membrane- Cilia beat rhythmically and move particles away from lungs

Trachea or Windpipe

Trachea

• Contains C-shaped cartilage

• Keeps airways opened and prevent it from collapsing


atmosphere

external nostril

nasal passages

pharynx

larynx

trachea

bronchi

external nostril

trachealarynx

pharynx

bronchi

nasal passages


Adaptations of the Trachea & Bronchi WALL

• Gland cells secrete mucus

to trap dust particles and bacteria

• Lined with epithelium bearing cilia

Cilia: sweeps particles upwards to pharynx

Adaptations of the Trachea & Bronchi


atmosphere

external nostril

nasal passages

pharynx

larynx

trachea

bronchi

Bronchioles (Not supported

by cartilage)

external nostril

trachealarynx

pharynx

bronchi

bronchioles

nasal passages



atmosphere

external nostril

nasal passages

pharynx

larynx

trachea

bronchi

bronchioles

Alveoli (For gaseous

exchange)

external nostril

trachealarynx

pharynx

bronchi

bronchioles

cluster of alveoli (air sacs)

nasal passages

Structure of Alveolus (Plural:alveoli)

Passage of air through respiratory system

One-cell thick wall

Oxygen

Adaptations of the alveoli for efficient gaseous exchange

Feature Function

Numerous alveoli To increase the surface area for gaseous exchange

Wall of alveoli is one-cell thick

To ensure rapid diffusion of gases, between alveolus and capillary

A thin film of moisture on surface of alveolus

To allow oxygen to dissolve and diffuse into the capillary bloodstream

Rich supply of blood capillaries

Ensure constant flow of blood to maintain a steep concentration gradient for efficient gaseous exchange

Technology

Respiration 3 e_part 1