36
1 AEROBIC & ANAEROBIC RESPIRATION BIOLOGY FORM 4

281_AEROBIC & ANAEROBIC RESPIRATION

Embed Size (px)

Citation preview

Page 1: 281_AEROBIC & ANAEROBIC RESPIRATION

1

AEROBIC & ANAEROBIC RESPIRATION

BIOLOGY FORM 4

Page 2: 281_AEROBIC & ANAEROBIC RESPIRATION

2

RESPIRATION

• Advantages of ATP: - 1. ATP is stored so that it can be released

when needed

2. ATP is stored in small packages so that the cell can use small quantities as required. No wastage.

3. ATP stores chemical energy in a useful form

Page 3: 281_AEROBIC & ANAEROBIC RESPIRATION

3

ANAEROBIC RESPIRATION

• Respiration without O2

• Glucose isn’t completely broken down

• Less energy is released i.e. fewer ATP molecules formed

• Occurs in areas where O2 deficient such as stagnant pools and underground.

• Organisms such as worms, bacteria which live in these areas respire anaerobically

• See pg 86 of Atwaroo-Ali for comparison

Page 4: 281_AEROBIC & ANAEROBIC RESPIRATION

4

ANAEROBIC RESPIRATION IN HUMANS

• MUSCLE CELLS– O2 supply is short when working vigourously,

because blood can’t reach muscles quickly to deliver enough O2 for aerobic respiration

– Breathing & heart rates increase to bring O2 to muscles cells

– Glucose is broken down into lactic acid– Glucose lactic acid + some energy

– C6H12O6 2C3H6O3 + energy

Page 5: 281_AEROBIC & ANAEROBIC RESPIRATION

5

ANAEROBIC RESPIRATION IN HUMANS

• MUSCLE CELLS– Lactic acid is waste product which builds up in

muscles which causes them to ache. This is called fatigue.

– Lactic acid builds up in bloodstream causes muscle cramps

– After exercise the body must get rid of lactic acid – does this by panting to increase O2 entering the body – glucose is formed – broken down in aerobic respiration

– O2 required to remove lactic acid is called O2 debt (i.e. volume of O2 needed to oxidise lactic acid)

Page 6: 281_AEROBIC & ANAEROBIC RESPIRATION

6

ANAEROBIC RESPIRATION IN YEASTANAEROBIC RESPIRATION IN YEAST

• Yeast – single celled organisms important Yeast – single celled organisms important in making wine, bread & beerin making wine, bread & beer

• Glucose broken down to ethanol & COGlucose broken down to ethanol & CO22

• Glucose ethanol + carbon dioxide + Glucose ethanol + carbon dioxide + energyenergy

• CC66HH1212OO6 6 2C2C22HH55OH + OH + 22COCO22 + energy + energy

• COCO22 makes the dough rise while ethanol makes the dough rise while ethanol

evaporates in the ovenevaporates in the oven

Page 8: 281_AEROBIC & ANAEROBIC RESPIRATION

8

GASEOUS EXCHANGE IN HUMANS

• Breathing consists of ventilation which is the mechanism that moves air in & out of the lungs & enables gas exchange to occur, between the air in the lungs and the gases dissolved in the blood.

• STRUCTURE OF THE RESPIRATORY SYSTEM/ROUTE BY WHICH AIR REACHES THE LUNGS

• Nose/Mouth Trachea/windpipe Bronchi Bronchiole Alveoli

Page 9: 281_AEROBIC & ANAEROBIC RESPIRATION

9

GASEOUS EXCHANGE IN HUMANS

Arrangement of organs in the respiratory system of humans

Page 10: 281_AEROBIC & ANAEROBIC RESPIRATION

10

GASEOUS EXCHANGE IN HUMANS

• ROUTE BY WHICH AIR REACHES THE LUNGS

• Nose – Air is drawn into the nose through the nostrils. Inside

the nose is warm & moist. Moist because its lining produces mucus, & warm because of the numerous blood vessels close to the surface.

– At the back of nose – nasal cavity which is divided up by bony partitions to give it a large S.A. Air becomes warm, moist & cleaned when it passes over these surfaces.

– Dust & germs get caught by mucus, then moved towards throat by beating cilia. Mucus contains a substance which kills germs.

Page 11: 281_AEROBIC & ANAEROBIC RESPIRATION

11

GASEOUS EXCHANGE IN HUMANS

• Nose– Mucus is removed by being swallowed, coughed up or blown

through the nose– Nose lining is sensitive to touch, hence reason why we sneeze– All these are ways to protect lungs from germs.

• The lining of the nasal cavity possesses sensory cells sensitive to smell.

• Our sense of smell tells us whether the air is suitable for breathing thus allowing us to test it before it enters our lungs.

• Function of nose??? – Warms, moistens, cleans & tests the air. Also protects the lungs

from germs & harmful substances that may injure them or cause an infection.

Page 12: 281_AEROBIC & ANAEROBIC RESPIRATION

12

GASEOUS EXCHANGE IN HUMANS

• Nose– Breathing through the mouth doesn’t have the same

protective functions as the nose and increases the risk of infection.

– Leading from the nasal cavity are a number of cavities called sinuses which produce mucus that drains into the nasal cavity. The holes connecting the sinuses with the nasal cavity are small, & if a person gets a cold they get swollen & blocked. Then the sinuses fill up with fluid, pressure builds up – may cause a headache.

Page 13: 281_AEROBIC & ANAEROBIC RESPIRATION

13

GASEOUS EXCHANGE IN HUMANS

• Throat– Part of resp. & digestive systems.– Air enters windpipe through small hole

(glottis). Food is prevented from entering glottis by flap of tissue called epiglottis.

– When breathing epiglottis closes glottis– Glottis opens into voice box/larynx (Adam’s

apple). Feels hard due to pieces of gristle. When air is forced through voice box, cause vocal cords to vibrate, which produces sound

Page 14: 281_AEROBIC & ANAEROBIC RESPIRATION

14

GASEOUS EXCHANGE IN HUMANS

• Windpipe/trachea– Straight tube about 12cm long in front of gullet– Windpipe is kept open by rings of gristle/cartilage

which stiffen its wall like hose of a vacuum cleaner.– These rings are ‘C’ shaped arranged so that the open

part of the ‘C’ is next to the gullet. This allows the gullet to expand as food passes through it.

– Inner lining of the w/pipe has cilia & produces mucus which catches dust and germs not caught by nasal cavity. After the mucus is coughed up or swallowed.

– Hence w/pipe also helps to prevent germs & harmful substances from entering the lungs.

Page 15: 281_AEROBIC & ANAEROBIC RESPIRATION

15

GASEOUS EXCHANGE IN HUMANS

• Bronchi– The w/pipe splits into 2 tubes called bronchi (singular:

bronchus) where one leads to one lung. Bronchi are similar to w/pipe in that also has cartilage/gristle except narrower

• Bronchioles– Within each lung the bronchi divides into numerous

branches called a bronchial tree. The branches are called bronchioles. They have very narrow ends and their walls contain smooth muscle which allows them to widen or get narrower when necessary.

Page 16: 281_AEROBIC & ANAEROBIC RESPIRATION

16

GASEOUS EXCHANGE IN HUMANS

• Alveoli– Each bronchiole leads to a bunch of tiny sacs called

alveoli (sing: alveolus) which are the sites for gaseous exchange.

– Alveoli are closely surrounded by a network of blood capillaries (see pg. 93 Atwaroo-Ali) & the membrane separating them is extremely thin.

• Blood is pumped from the heart to the lungs & passes through the capillaries surrounding the alveoli.

• The blood has come from respiring tissues from the body, where it has given up some of its O2 to the cells & gained CO2.

Page 17: 281_AEROBIC & ANAEROBIC RESPIRATION

17

GASEOUS EXCHANGE IN HUMANS

• Around the lungs, the blood is separated from air inside each alveolus by 2 cell layers; the cells making up the alveolus’ wall and the capillary wall which is a distance of 1/1000th of a millimetre.

• Since air in alveolus has higher conc. of O2 than blood entering capillary network, O2 diffuses from the air across alveolus wall into blood. At the same time, more CO2 in blood than in the air in lungs. Thus there is a conc. gradient for CO2 in the other direction so CO2 diffuses the other way out of the blood & into the alveolus. Therefore blood which leaves the alveolus and flows back to the heart has gained O2 but lost CO2. the heart pumps the blood around the body again to supply respiring cells.

Page 18: 281_AEROBIC & ANAEROBIC RESPIRATION

18

GASEOUS EXCHANGE IN HUMANS

• Alveoli

Page 19: 281_AEROBIC & ANAEROBIC RESPIRATION

19

GASEOUS EXCHANGE IN HUMANS

• Remember what makes alveoli good respiratory surfaces!!!

• Study inhalation & exhalation on page 95 of Atwaroo-Ali. Also page 68 in Chinnery. You may be asked to draw in final Form 5 exams!!!

• Draw diagrams on pages 92 & 93 (Fig. 9.2, 9.3, 9.4 & 9.5 in your notebook.

• STUDY TABLE 9.1 (put in book) & EFFECTS OF SMOKING

Page 20: 281_AEROBIC & ANAEROBIC RESPIRATION

20

GASEOUS EXCHANGE IN HUMANS

• THE LUNGS– When we breathe in, air is sucked into lungs (main

organs of resp. system)– They are light & soft with spaces like a sponge. These

spaces are filled with air. O2 is taken up from this air into the blood. CO2 passes in the opposite direction. This movement of gases is gaseous exchange.

• We possess 2 lungs situated side by side in the chest/thorax.

• The side of the chest are bounded by the ribs, which are joined to the backbone/vertebral column at the back & the breastbone/sternum in the front

Page 21: 281_AEROBIC & ANAEROBIC RESPIRATION

21

GASEOUS EXCHANGE IN HUMANS• THE LUNGS cont’d• Between the ribs are muscles called intercostal

muscles. The thorax is separated from the abdomen below by the diaphragm, which is a sheet of muscular tissue, shaped like a dome, stretched across between the bottom-most ribs.

• Each lung is surrounded by 2 thin sheets of tissue – pleural membranes/layers. The inner one covers the lungs while the outer one lines the inside of the thorax. Between them is a narrow space (pleural cavity) containing pleural fluid which serves as a lubricant preventing the lungs’ surfaces to stick to the inside of the chest cavity when we breathe.

Page 22: 281_AEROBIC & ANAEROBIC RESPIRATION

22

RESPIRATION EXPERIMENTS

Page 23: 281_AEROBIC & ANAEROBIC RESPIRATION

23

1.1. To Show Products of Anaerobic Respiration in To Show Products of Anaerobic Respiration in YeastYeast

thermometer

yeast in glucose solution which has

been previously boiled and then

cooled down

hydrogencarbonate indicator solution/lime

water

liquid paraffin

thermos flask

Page 24: 281_AEROBIC & ANAEROBIC RESPIRATION

24

1.1. To Show Products of Anaerobic Respiration in To Show Products of Anaerobic Respiration in YeastYeast

Q. Under what condition will yeast carry out fermentation?A. Anaerobic condition

Q. How are you going to provide this condition?A. Boil the glucose solution to drive out any dissolved air.

Add a layer of paraffin oil on top of the mixture of glucose and yeast.

Q. Why is it important to boil the glucose solution?A. This drives off any dissolved oxygen.

Q. Why must the glucose solution be cooled down before yeast is added?

A. It is because yeast would be killed when hot.

Page 25: 281_AEROBIC & ANAEROBIC RESPIRATION

25

Q. What are the controlled variables in this experiment?

A. Temperature, pH, volume of glucose solution, etc

Q. What is the independent variable (what is manipulated) in this experiment?

A. Whether the yeast is living or dead.

Q. What is the dependent variable (i.e. the result) in this experiment?

A. The production of ethanol, carbon dioxide or heat.

Page 26: 281_AEROBIC & ANAEROBIC RESPIRATION

26

To Show Products of Anaerobic Respiration To Show Products of Anaerobic Respiration in Yeastin Yeast

thermometer

yeast in glucose solution which has

been previously boiled and then

cooled down

hydrogencarbonate indicator solution/lime

water

liquid paraffin

thermos flask

Page 27: 281_AEROBIC & ANAEROBIC RESPIRATION

27

Q. What is the function of liquid paraffin?

A. It prevents the mixture from coming into contact with air.

Q. What has happened to the hydrogencarbonate indicator solution or lime water solution?

A. The hydrogencarbonate indicator solution has changed from red to yellow. Lime water will turn milky white.

Q. What does this show?A. This shows that yeast can respire anaerobically

to produce energy.

Page 28: 281_AEROBIC & ANAEROBIC RESPIRATION

28

To Show Products of Anaerobic Respiration To Show Products of Anaerobic Respiration in Yeastin Yeast

Q. What is the control in this experiment?A. Boiled yeast suspension

Q. At the end of the experiment, what new substance would you expect to find in the glucose solution containing living yeast?

A. Alcohol

Page 29: 281_AEROBIC & ANAEROBIC RESPIRATION

29

2. To Show Production of a Gas by a 2. To Show Production of a Gas by a Respiring Animal Respiring Animal

pg 337 Atwaroo - Alipg 337 Atwaroo - Ali

lime water/

bicarbonate of soda

lime water/

bicarbonate of soda

to suction pump

CBA

potassium hydroxide

solution

glass platemouse

bell jar

Page 30: 281_AEROBIC & ANAEROBIC RESPIRATION

30

Q. Why is it necessary to bubble the incoming air through potassium hydroxide solution before it is supplied to the mouse ?

A. Remove carbon dioxide in the incoming air. One can observe that any carbon dioxide detected in flask C is due to the mouse.

lime water/

bicarbonate of soda

lime water/

bicarbonate of soda

to suction pump

CBA

potassium hydroxide solution glass plate

mouse

bell jar

Page 31: 281_AEROBIC & ANAEROBIC RESPIRATION

31

Q. What are the functions of the lime water/bicarbonate of soda or redred hydrogencarbonate indicator in flasks B and C?

A. Flask B: To test whether there is any carbon dioxide in the air entering the bell jar.

Flask C: To test whether there is any carbon dioxide in the air leaving the bell jar

Q. What can you tell from the result of flask B?A. Carbon dioxide is absentabsent in the air entering the

bell jar.

Q What can you tell from the result of flask C?A. Carbon dioxide is releasedreleased by the mouse

Page 32: 281_AEROBIC & ANAEROBIC RESPIRATION

32

To Show Production of a Gas by a Respiring To Show Production of a Gas by a Respiring AnimalAnimal

Q. How would you set up a control for this practical?

A. Set up a similar apparatus without putting a mouse in the bell jar.

Q. What precautions should be taken if the mouse is replaced by a

potted plant? Explain

A. Wrap the pot with a plastic bag. Otherwise, carbon dioxide released

by the micro-organisms in the soil will affect the results. Cover Cover

the bell jar with a black cloththe bell jar with a black cloth. Otherwise, the plant will absorb

carbon dioxide for photosynthesis and this will affect the

results of the respiration experiment.

Page 33: 281_AEROBIC & ANAEROBIC RESPIRATION

33

3. To Demonstrate Heat Production by 3. To Demonstrate Heat Production by Germinating Seeds using Thermos FlasksGerminating Seeds using Thermos Flasks

A

thermos flask

germinating seeds

cotton wool

thermometer

B

Seeds killedby boiling

Page 34: 281_AEROBIC & ANAEROBIC RESPIRATION

34

Q. What are the controlled variables in this experiment?

A. Amount of seeds in the vacuum flasks.

Q. What is the independent variable in this experiment?

A. Whether the seeds are livingliving or boiledboiled.

Q. What is the dependent variable in this experiment?

A. A. TemperatureTemperature as recorded by the thermometers.

Page 35: 281_AEROBIC & ANAEROBIC RESPIRATION

35

Q. Why were the flasks inverted and corked with cotton?

A. Inverted flasks: CO2 is denser than air. Cotton: allow CO2 to escape otherwise it will kill the beans/peas.

Q. Why were the beans/peas washed with disinfectant?

A. To kill any micro-organisms/bacteria which may respire and affect the results.

Page 36: 281_AEROBIC & ANAEROBIC RESPIRATION

36

Q. What is the control in this experiment?A. The boiled seeds.

Q. What precautionsprecautions should be taken?A. Put the bulbs of the thermometers in the

seeds, not the air inside the vacuum flasks. Make sure that the seeds completely cover the bulbs of the thermometers. Do not fill up the whole vacuum flasks with seeds or there will not be enough air for the seeds to carry out respiration.