7.3 Gaseous Exchange across the Respiratory Surfaces

Able to explain in detail the process of gaseous exchange at alveolus

-       The partial pressure of oxygen in the air of alveoli is higher compared to the partial pressure of oxygen in the blood capillaries

-       Therefore, oxygen diffuses across the surface of the alveolus and blood capillaries.

-       Then oxygen will combine with haemoglobin to form oxyhaemoglobin 

-       Lastly this form will be transported to all parts of the body.

greenhouse effects

                                              

EXPLAIN WHAT THE GREENHOUSE EFFECT IS

-Caused by GREEN HOUSE GASES : Carbon dioxide, methane, nitrous oxide

- Carbon sources : combustion of fuel, deforestation, industrial production

chapter 3 : plasma membrane

(a)  The plasma membrane is said to be semi-permeable.

       What is the meaning of ‘semi-permeable’?

        A semi-permeable plasma membrane allows only certain substances
         to move freely across it while others cannot. 

(b) Describe how the particle moves across each of the following structures. i-Carbon dioxide / Oxygen / Glycerol /Fatty acid by Simple diffusion  through phospholipid bilayer ii-Water  by osmosis through pore protein iii -Glucose /Amino acid by facilitated diffussion through carrier protein iv- Sodium ion/pottasium by active transport through carrier protein and needs energy of ATP. /Potassium ion

Compare and contrast : aerobic n anaerobic

similarities :

-          takes place in animal and plant cells

-          are respiratory processes in the cells

-          involve the catabolism of glucose molecules

-          produce ATP molecules

-          are enzyme-catalysed anabolisms of ATP

-          involve energy expenditure

-          produce heat energy as a by- product

                                                 differences :
aerobic                                                                                   anaerobic

Need oxygen<----------- Oxygen requirement------------>Not needed

    

Complete <--------------Oxidation of glucose ------------>Incomplete

Carbon dioxide,<--------Product of respiration---------->Lactic acid and energy ( for animal).

water,energy                                                                     Ethanol, CO2, energy ( for Yeast)

36 for each glucose molecule   <---------Total ATP molecule-------> 2 for each glucose molecule

?????? <------------             Energy produced per glucose molecule    --------> ????????

 

 

???????? <-----------                    place of occurrence                         ------------> ?????????

??????? <------------                       Carried out by                               ------------> ????????

?????? <------------                     Chemical equations                             -----------> ???????

Chapter 7 : Respiration

Able to explain 3 common  adaptations of  thé respiratory structure

·         The number of structures is high that provide large surface area

·         The thickness of the structure is thin which  also provides the large surface area

·         The inner surface is lined with a layer of moist epithelial cells which easily dissolve the oxygen

Chemical equation in aerobic respiration:

C₆ H₁₂ O₆  +  6 O_{2 ------------------}6CO₂ + 6H₂O + energy( 2898 kJ)

(glucose)       ( Oxygen)   ( Carbon dioxide) ( Water)       

anaerobic respiration

Chemical equation in animal:

C₆ H₁₂ O_{6-----------------------}2C₃ H₆ O₃    +Energy(210 kJ)

(glucose)                  (lactic acid)

                               

anaerobic respiration

Chemical equation in plant:

C₆ H₁₂ O₆  ----------- 2C₂ H₅ OH + 2CO₂ + Energy

(glucose)               ( ethanol)  (Carbon dioxide) ( 210kJ)

                             

               

EXPLAIN THE THINNING OF THE OZONE LAYER

EXPLAIN THE THINNING OF THE OZONE LAYER

-          Depletion of the ozone layer (Region in the stratosphere between 20-25 km)

Able to explain what ozone is

·        Ozone is a molecule made up of three oxygen atoms//O₃

·        It is an (extremely) unstable molecule.

·        It forms a layer in the earth’s stratosphere (20-50 km from the earth’s surface)

                           

Able to explain the  importance of the ozone layer to humans.

It acts as a natural shield to protect the earth from ultraviolet radiation// It filters ultraviolet radiation so that only a small amount of it reaches the earth’s surface. 

Able to describe how the ozone layer becomes thinner

·        Thinning of the ozone layer is due to the widespread use of CFC/ Chlorofluorocarbon.

·        CFC is made up of carbon, fluorine  and chlorine

·        It is used in aerosol/ industrial solvents/as a coolant in air conditioners.

·        When ultraviolet rays strikes a CFC molecule (in the stratosphere), it causes a Chlorine atom to break away (from the CFC)

·        The free chlorine atom then collides with an ozone molecule and forms chlorine monoxide and an oxygen molecule

·        When a free oxygen atom collides with the chlorine monoxide molecule, an oxygen molecule and a free chlorine atom is produced.

·        The free chlorine atom then continues to destroy the ozone molecules

·        Each atom of chlorine can destroy thousands of ozone molecules.

-          Caused by Chlorofluorocarbons (CFCs)

-          CFCs sources: Coolant on air conditioners, Propellants in aerosol, Foaming agents (making styrofoam )

Able to describe the effect of the thinning of the ozone layer on organisms and the environment.

     

·        Causes an increase in the occurrence of cataracts and blindness.

·         An increase in the incidence of skin cancer.

·        Lowers the immunities against diseases/ lowers

      effectiveness of vaccinations.     

·        Ultraviolet radiation kills plankton in the sea. This affects the food chain of marine life

Ultraviolet radiation reduces the number of stomata and

• Affects : Skin cancer –melanoma
• Cataracts
• Sunburns
• Weakened immune system
• Lower the rate of photosynthesis, lower the crop yield
• Reduce nutrient contents (soya beans and peas) 
•         chlorophyll of the leaves of plants on land// This reduces the rate of photosynthesis in plants/ the productivity of the plant. Thus affecting the food chain .
  
  

Chapter 9:  Endangered Ecosystem

Effects of human activities that endangered an ecosystem

- Deforestation : Soil Erosion, Flash Flood, Land slide

                                Effects to animals n plants : siltation, destroy habitat

- Agriculture : Eutrofication, Pollution

-Industralisation : Green House Effect, Global Warming, Climatic Change

- Urbanisation : Increase in Domestic and Industrial Waste

These affects  and leads to extinction of animal n plants

THE GREEN HOUSE EFFECTS AND THE THINNING OF THE OZONE LAYER

LEARNING OUTCOME

·        EXPLAIN WHAT THE GREENHOUSE EFFECT IS

·        CORRELATE THE CONCENTRATION OF CARBON DIOXIDE IN THE ATMOSPHERE WITH GLOBAL WARMING

·        EXPLAIN THE THINNING OF THE OZONE LAYER

·        EXPLAIN THE IMPACT OF THE THINNING OF THE OZONE LAYER AND GLOBAL WARMING ON THE ECOSYSTEM