1. 1.3 Extracting Energy from Biomass
Photosynthesis produces glucose and oxygen from carbon dioxide, water and light energy
Not all organisms undergo photosynthesis, but all organisms get energy from glucose
Single celled bacteria to complex life forms like humans
For organisms to release and use the energy, the glucose has to be broken down

2. Fermentation which occurs when oxygen is absent = anaerobic conditions
Once glucose is broken down, cells can extract the energy to complete the processes that are essential to life
There are two main processes through which organisms extract the energy from glucose:
Cellular Respiration which occurs when oxygen is present = aerobic conditions
Fermentation which occurs when oxygen is absent = anaerobic conditions
Humans uses cellular respiration, organisms such as bacteria and some fungi use fermentation to release the energy in glucose

3. Cellular Respiration
The most common and efficient method for extracting the energy from glucose is cellular respiration.
Plants, animals, fungi use cellular respiration
Bring to attention the variety of life forms that use cellular respiration

4. Cellular Respiration
In cellular respiration, as well as in fermentation, the glucose that was assembled by photosynthesis is broken down to make the energy available to body cells
Remember: solar energy from the Sun is converted into chemical energy called glucose by a process called photosynthesis
Assembled or synthesized
All the energy you use comes from cellular respiration, blinking, breathing, walking, playing volleyball

5. The chemical formula for cellular respiration:
C6H12O O2 6CO H2O + energy
In contrast to photosynthesis, cellular respiration consumes oxygen and produces carbon dioxide
Glucose Sugar
Oxygen
Carbon Dioxide
Water
Chemical formula for cellular respiration, looks familiar to photosynthesis

6. Extracting Energy from Food
Most organisms require oxygen to extract energy from food = aerobic conditions
In cellular respiration, organisms take in oxygen which reacts with the glucose in cells to produce carbon dioxide, water and energy
If conditions are anaerobic = no oxygen, then fermentation is used

7. Plants break down the glucose through cellular respiration
Even though plants produce their own food through photosynthesis, they still have to break down glucose to get energy from it
Plants break down the glucose through cellular respiration
During day and night, need energy all the time to live
Photosynthesis is active only during the day though
WHY?
Photosynthesis means you can make your own energy but you still have to utilize that energy using cellular respiration
Page 29 diagram

8. CO2 and Other Greenhouse Gases
Greenhouse gases are atmospheric gases that prevent heat from leaving the atmosphere, therefore increasing the temperature of the atmosphere
Ex: water vapour, carbon dioxide, methane
Without greenhouse gases, Earth’s temperatures would average less than 0oC
natural insulator
Balance, don’t associate term with something negative, they are essential for life on Earth

9. Greenhouse Effect: the warming of the Earth as a result of greenhouse gases

10. Biomass and Fossil Fuels
Scientists have concluded that single celled organisms used photosynthesis to generate biomass more than 3 billion years ago
Most of the matter in this biomass has been cycled through the biosphere countless times
What are the 4 spheres?

11. Biomass and Fossil Fuels
Small amounts escaped the biosphere’s cycling system when the remains of organisms settled in places where there was not enough oxygen to decompose them
Over time, with pressure and heat, the biomass changed into fossil fuels such as: Coal, Petroleum and Natural Gas

12. Biomass and Fossil Fuels
Fossil fuels come from biomass that was produced by photosynthesis millions of years ago
Therefore it is not surprising that burning them has an effect that is similar to cellular respiration
Both processes consume oxygen, release energy and produce carbon dioxide

13. Enhanced Greenhouse Effect
Fossil fuels have been accumulating for many millions of years
Significant portions of Earth’s reserves have been burned by humans in a span a few centuries
Since humans have “suddenly” released much of the carbon dioxide that was converted to biomass by ancient plants
= the net result for the atmosphere is added CO2

14. Enhanced Greenhouse Effect
Since the Industrial Revolution in the 1700s, the concentration of CO2 in the atmosphere has increased
This era marked the start of an increased and widespread burning of fossil fuels as a source of energy

15. Enhanced Greenhouse Effect
Many scientists believe that the increased concentration of CO2 in the atmosphere along with an increase in other greenhouse gases, such as methane, is the cause of global warming
Global warming is the increase in Earth’s average surface temperature
Video
Greenhouse Effect: Climate Control and Global Warming 5 min

16. Reducing CO2 in the Atmosphere
There are many ways to reduce the amount of CO2 being released into the atmosphere, including:
International initiatives by governments from around the world
Initiatives by the federal, provincial and local governments of Canada
Efforts by individuals!

17. Reducing CO2 in the Atmosphere
Example: Kyoto Accord
International agreement to reduce greenhouse gas emissions, signed by over 180 countries in 1997
Canada withdrew in 2011, USA did not formally consent to agreement

18. Example: Protecting existing forests
In 2008, Ontario announced that half of its forests will be protected
km2 of forest will be protected from logging, mining and fossil fuel exploration
The Boreal forest in Ontario is a carbon sink
= absorbs about 12 million tonnes of CO2/year
Replant trees after cutting them down also

19. Example: Recycling Programs
Recycling helps to reduce carbon dioxide emissions because less energy is needed to make something from recycled materials than from new materials
Ex: energy input is reduced by 95% when an aluminum product is made from recycled aluminum rather than a raw material
CO2 emission reduction: there are solutions! 6:42 min
Homework page 31, Learning Check #1-4, page 36 #1, 2, 4