2011 cellular respiration

bio test in Week 4• 3R1 and 3R6 on Monday 03/10 • while 3R2 and 3R5 on Tue 04/10

Topics(1)Transport in Mammals and (2)Respiration only.

Cellular Respiration

Chapter 10

Lesson Objectives

Cellular Respirationf) Define aerobic g) anaerobic respiration Write word equations for each type. h) Removal of lactic acid in muscles when anaerobic respiration occurs.

Respiration Gaseous exchange in lungsb) State characteristics of gaseous exchange surface of the alveoli. c) Describe removal of carbon dioxide from lungs including role of carbonic anhydrase enzyme. i) Describe the effect of tobacco smoke and its major toxic components.

Mechanism of breathing a) Identify parts of the respiratory tract.

e) Describe role of cilia, diaphragm, ribs and intercostal muscles.

Think about this

• Do respiration and breathing refer to the same processes?

What’s the difference? (Pg 194)

http://www.teachhealthk-12.uthscsa.edu/studentresources/AnatomyofBreathing3.swf

What is respiration?

Respiration is the oxidation of glucose or another organic chemical which releases energy in living cells.

Why respiration?

Respiration is the oxidation of glucose or another organic chemical which releases

energy in living cells.

What are some of the uses of energy in our body?

Where does respiration take place?• Takes place in the mitochondria of

all living cells (plants & animals)

Where do we get our energy from?

In , there are many

These mitochondria =

Respiration in mitochondria of living cells releases energy. (*Release NOT Produce)

Oxidation

Respiration

Oxidation VS Respiration (Pg 194)

Aerobic Respiration is the oxidation of glucose or another organic chemical in the presence of oxygen with the release of large amount of energy. Carbon dioxide and water are released as waste products.

Anaerobic Respiration is breakdown of glucose or another organic chemical in the absence of oxygen. Lesser energy is released.


• Controlled by many enzymes

• Word Equation

• Chemical EquationC6H12O6 + 6O2 6CO2 + 6H2O + ENERGY

(38 moles of ATP)

Glucose + Oxygen Carbon dioxide + Water

+ Energy

(large amount)

38 moles of ATP

http://www.purchon.com/biology/flash/respiration.swf

What happens to the energy produced?• Most of the energy is lost as heat

energy

• Remaining energy is first stored in mitochondria as a chemical compound adenosine triphosphate (ATP)

• Energy released from ATP is used for vital cellular activities


Mammals Plants Glucose

Lactic acid + small amount of energy (2 moles ATP)

Glucose

Ethanol + carbon dioxide + small amount of energy

(3) What is anaerobic respiration?• Incomplete breakdown of glucose in the

absence of oxygen with the release of a small amount of energy

• Takes place in– All plants, yeasts, some bacteria and fungi– Muscles of humans and other mammals

during strenuous exercise– Mammals which dive for a long period of time

in the ocean e.g seals and whales

What happens when plants respire anaerobically?

• Word Equationglucose carbon dioxide + ethanol +

energy

• Chemical Equation

C6H12O6 2C2H5OH + 2CO2 + ENERGY

(2 moles of ATP)

Alcoholic fermentation

What happens when humans exercise strenuously?

• Initially muscles respire aerobically• Increase in heart rate and

breathing rate• Limit to the rate of heart beat• Oxygen cannot be transported to

muscles fast enough for tissue respiration

Lactic acid production

What happens when we exercise strenuously?

• Insufficient oxygen causes the muscles to respire anaerobically to release energy

• Glucose is broken down to lactic acid instead of carbon dioxide and water

• Lactic acid accumulates in muscles and causes muscle cramps and fatigue

What happens when we exercise strenuously?• Word equation

Glucose lactic acid + energy

• Chemical equation

C6H12O6 2C3H6O3 + ENERGY

(2 moles of ATP)

What is lactic acid?

• Lactic acid is a mildly poisonous chemical

• During period of rest, lactic acid is removed from muscles and transported to liver

• In liver 20% of lactic acid is oxidised completely to water and carbon dioxide

• Energy produced used to convert the remaining lactic acid to glucose

(4) What is oxygen debt and recovery period?

• Oxygen debt– The amount of oxygen needed to

oxidise the lactic acid produced during anaerobic respiration

• Recovery period– Time taken to remove lactic acid from

the body in 2 ways

Fate of Lactic Acid?• For further oxidation in liver to

produce energy

• Energy from above will be used for conversion of remaining lactic acid into glucose

– Glucose obtained from lactic acid can be further oxidised.

2.5 What is oxygen debt and recovery period?

Oxygen consumed during exercise

Oxygen debt

Oxygen consumed during rest



• oxygen required • oxygen is not required

• large amount of energy released

• small amount of energy released

• carbon dioxide & water produced

• lactic acid (mammals) and ethanol & carbon dioxide (plants) produced

EXPERIMENTS ON RESPIRATION

Aim: To find out whether carbon dioxide is given off during respiration

Caustic potash solution

Limewater Germinating seeds

Limewater

1. You need to set up a control. What would you put in the conical flask?

2. What purpose does the caustic potash solution serve?

3. What purpose does the limewater serve?

4. What happens to the limewater in C after some time? Explain your answers.

Hint:

caustic potash solution is potassium hydroxide

Boiled seeds

To absorb carbon dioxide

To ensure that there is no more carbon dioxide present in the air supplied to the seeds

White ppt formed. Germinating seeds give out carbon dioxide during respiration.

Investigation 2

Aim: To find out whether heat is produced during respiration.

Lesson Objectives


Respiration Gaseous exchange in lungsb) State characteristics of gaseous exchange surface of the alveoli. c) Describe removal of carbon dioxide from longs including role of carbonic anhydrase enzyme. i) Describe the effect of tobacco smoke and its major toxic components.



In this chapter, you should be able to:

Describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing.

State the difference between inspired and expired air.

State the effect of physical activity on rate and depth of breathing.

atmosphere

Path of Air Through the Respiratory System

atmosphere

external nostril

external nostril


atmosphere

external nostril

nasal passages

external nostril

nasal passages


atmosphere

external nostril

nasal passages

pharynx

external nostril

pharynxnasal passages


atmosphere

external nostril

nasal passages

pharynx

larynx

external nostril

larynx



atmosphere

external nostril

nasal passages

pharynx

larynx

trachea

external nostril

trachealarynx



atmosphere

external nostril

nasal passages

pharynx

larynx

trachea

bronchi

external nostril

trachealarynx

pharynx

bronchi

nasal passages


atmosphere

external nostril

nasal passages

pharynx

larynx

trachea

bronchi

bronchioles

external nostril

trachealarynx

pharynx

bronchi

bronchioles

nasal passages


Respiratory System

atmosphere

external nostril

nasal passages

pharynx

larynx

trachea

bronchi

bronchioles

alveoli

external nostril

trachealarynx

pharynx

bronchi

bronchioles

cluster of alveoli (air sacs)

nasal passages

What are the differences b/w inspired & expired air?

Inspired air Expired air

Oxygen

Carbon dioxide

Nitrogen

Water vapour

Temperature

Dust particles

21 % 16 %

0.03 % 4.0 %

78 % 78 %

unsaturated saturated

variable about body temp.

variable little, if any

As air enters the body:

Nostrils

• air is filtered

dust, foreign particles & bacteria are removed

Nasal cavity

Dust, foreign particles & bacteria are removed

• fringe of hair (in nostril)

• fringe of cilia (on epithelial cells along trachea)

• mucus (produced by gland cells)

Gland cell Epithelial cell

Sweeping action of cilia moves mucus along

As air enters the body:

Nostrils

• air is filtered

Nasal cavity

• air is warmed & moistened

• harmful chemicals are detected

by sensory cells (in mucous membrane)

Air passes the epiglottis and enters the lungs via the trachea

Nostrils

Nasal cavity

Epiglottis Trachea

Larynx

Trachea C-shaped rings of cartilages

Lung

Gas exchange system in Human

The lungs are the organs involved in gaseous exchange. The trachea is supported by C-shaped rings of cartilage which ensures that it is always kept open.

Larynx

Trachea C-shaped rings of cartilages

Bronchus

(plural: bronchi)

Bronchioles

Lung


The trachea is branched into 2 tubes, the bronchi, one to each lung.

At the end of the bronchioles are clusters of air sacs (alveoli)


Ribs

Intercostal muscles

Between the ribs are 2 sets of muscles, external and internal intercostal muscles. When the external intercostal muscles contracts, internal intercostal muscles relaxes.

Diaphragm

The diaphragm is a dome-shaped sheet of muscle and elastic tissue.

What happens to the body during breathing?

When we breathe in,

• external intercostal muscles contract

• ribs swing upwards & outwards • diaphragm contracts & flattens

Volume of thoracic cavity

Pressure of air in cavity is lower than outside lungs

Air flows into lungs

What happens to the body during breathing?

When we breathe out,

• external intercostal muscles relax

• ribs swing downwards & inwards

• diaphragm relaxes & rises

Volume of thoracic cavity

Pressure of air in cavity is higher than outside lungs

Air flows out of lungs

A spirometer can be used to measure the amount of air taken in during inspiration.

Capacity of the lung

Tidal volume: volume of air which enters the lungs

per breath.

Inspiratory reserve volume (complementary volume): extra volume of air that can be taken in during a deep breath.

Expiratory reserve volume (supplement volume): extra volume of air that can be forced out in during a deep exhale.

Vital capacity: Volume of air taken in by taking the

deepest breath.

tidal vol. + inspiratory reserve + expiratory reserve vol.

Residual volume : volume of air always present in

lung

Lesson Objectives





What is the structure of an alveolus?

7) Oxygenated blood(joining pulmonary vein)

3) Thin film of moisture

4) Thin alveolus epithelium

8) Red blood cell

5) Thin capillary wall

6) Deoxygenated blood (from pulmonary artery)

1) Bronchiole

2) Alveolar cavity

Red blood cell

Blood capillary

Blood plasma

Alveolus

Tissue fluid

Deoxygenated blood Oxygenated blood

Air movement

Film of water

Gaseous exchange takes place between blood capillary and alveolus.

• Alveolar walls are very thin & moist

How are the alveoli adapted for gaseous exchange?

• Well supplied by blood capillaries

• Thousands are found in the lungs

Facilitate rapid diffusion of gases

Transports away oxygenated blood

surface area for gaseous exchange

How is the diffusion gradient maintained?

• constant flow of blood

• constant flow of air

Constant replacement of oxygenated blood by deoxygenated blood by blood flow

• Keeping the oxygen concentration high in alveolus by replenishing air in alveolus

• Rapid absorption of oxygen across the thin alveolus and capillary wall and formation of oxyhaemoglobin

How is the alveoli adapted for its function?

Feature FunctionNumerous alveoli Large SA for gas

exchangeThin walls of alveoli Rapid diffusion of

gasesThin film of moisture

Oxygen can dissolve

Dense capillary network

Rapid and efficient gas exchange

BUT how about carbon dioxide?

• Carbon dioxide– Carried as hydrogencarbonate ions in

deoxygenated blood breaks down to liberate carbon dioxide

– Carbon dioxide diffuses out of capillary wall, across alveolus wall into the alveolus

– Expelled out of the lungs during expiration

c) Describe removal of carbon dioxide from lungs including role of carbonic anhydrase enzyme.

RESPIRATION

• Occurs in living cells.

• Enzymes are involved.

• Oxidation of food substances with the release of energy.

April 11, 2023Copyright © 2006-2011 Marshall Cavendish International (Singapore) Pte. Ltd. 75

Aerobic Respiration

RESPIRATION





Aerobic RespirationAnaerobic

Respiration

RESPIRATION






Respiration

RESPIRATION

• Oxygen is required.

• Large amount of energy is released.

• Carbon dioxide and water are produced.






Respiration

RESPIRATION




• Oxygen is not required.

• Small amount of energy is released.

• Lactic acid is produced in mammals. Ethanol and carbon dioxide are produced in yeast.






Respiration

RESPIRATION







Differences






Respiration

RESPIRATION

Breathing mechanism







Differences






Respiration

How the body takes in oxygen and removes carbon dioxide

RESPIRATION

Breathing mechanism







Differences






Respiration


RESPIRATION

Breathing mechanism







Differences






Respiration


RESPIRATION

Breathing mechanism







Differences





Inspiration

• External intercostal muscles contract, internal intercostal muscles relax.

• Ribs move upwards and outwards.

• Diaphragm contracts and flattens.

• Volume of thorax increases.

• Air pressure in thorax decreases.

• Air flows into the lungs.


Respiration


RESPIRATION

Breathing mechanism







Differences





Inspiration







Expiration

• External intercostal muscles relax, internal intercostal muscles contract.

• Ribs move downwards and inwards.

• Diaphragm relaxes and arches upwards.

• Volume of thorax decreases.

• Air pressure in thorax increases.

• Air flows out of the lungs.


Respiration


RESPIRATION

Breathing mechanism







Differences





Inspiration







Expiration

• External intercostal muscles relax, internal intercostal muscles contract.

• Ribs move downwards and inwards.

• Diaphragm relaxes and arches upwards.

• Volume of thorax decreases.

• Air pressure in thorax increases.

• Air flows out of the lungs.Gaseous exchange

• Oxygen dissolves in film of moisture covering alveolar wall.

• Dissolve oxygen diffuses into blood capillaries.

• Carbon dioxide diffuses from blood into alveolar cavity.

Lesson Objectives





Technology

2011 cellular respiration