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Cellular Respiration and Photosynthesis- An Introduction
• Earth’s energy budget• Cellular energy (ATP)• Mitochondria• Solar energy• Chloroplasts• Chlorophyll• Photosynthesis vs. Cellular
Respiration• Photosynthesis and life
30% Reflected by Clouds or Earth’s Surface
19% Absorbed by Atmosphere and
Clouds
0.023% absorbed by
plants
Cell Currency (Payment)
• Currency = Energy = ATP
• We use currency (money) everyday in order to do things like buy food
• Cells use currency (ATP) to perform 1000’s of chemical reactions every second to keep them alive
ATP (Energy/Currency for the Cell)
• In order to keep the cell alive, it must perform 1000’s of reactions EVERY SECOND. Every reaction needs energy (ATP)
• ATP is created during cellular respiration inside the Mitochondria
Cellular Respiration• The process where sugar (glucose) is converted
into carbon dioxide, water and energy (ATP)
• The organism uses this energy to do everything
• Occurs in the mitochondria
energywaterdioxidecarbon oxygensugar
Mitochondria• "Powerhouse of the cell”
• Cells that use a lot of energy have more mitochondria (i.e. muscle cells, brain cells)
Solar Energy• Solar cells convert light
energy directly into electrical energy to work your TV, fan, etc.
• Plants do something similar. They convert light energy into chemical energy (sugar) which the organism can use to move, talk, run, etc.
Chloroplasts• Chloroplasts are located inside plants
• They contain chlorophyll which gives plants their green color and also allows them to absorb light energy and convert it to chemical energy in the form of sugar
This process is called Photosynthesis
• Performed in the Chloroplasts of plant cellsCarbon Dioxide + Water + Light Energy Glucose (Sugar) + Oxygen
Photosynthesis
Chlorophyll is a Pigment• Chlorophyll is the most important pigment
(color) present in plants. • Other pigments are also present in the leaf.–Carotenoids (orange / red)–Xanthophylls (yellow / brown)
Light• Light we see comes in a spectrum from purple to red• Different substances absorb different colors depending on
their structure• Colors that the substance doesn’t absorb, it reflects. We
see that reflection as the objects color
• Is a pigment that absorbs blue and red light but reflects green. The light is reflected into our eyes giving plants a green colour
Chlorophyll
High absorption
Low absorption/High reflection
How do plants use light? • Chlorophyll
pigments absorb blue and red regions of the spectrum. They reflect the green regions
• *Note* - reflecting green light also helps keep the plant cool
Carotenoids (other accessory pigments)
• Other accessory pigments (called carotenoids) also absorb light energy. They absorb green and reflect yellow-to-red light. This gives them a yellow-red colour
Why do some leaves turn colours in the fall?
There is one other main pigment found in plants, Xanthophylls. They reflect yellow/brown light
As the most abundant pigment, chlorophyll is what gives leaves their green color in spring and summer.
• During winter, there is not enough light or water for photosynthesis. Therefore, the trees cut off the circulation of water, nutrients and sugar to the leaves.
• The green chlorophyll pigment disappears from the leaves leaving the other pigments behind. As the green fades away, we see the yellows, oranges, reds and browns. Small amounts of these colors have been in the leaves all along we just can't see them in the summer, because they are covered up by the green chlorophyll.
Why do some leaves turn colours in the fall?
energywaterdioxidecarbon oxygensugar
oxygensugarwaterdioxidecarbon energylight
Photosynthesis
Cellular Respiration
Notice Anything?
Photosynthesis and Cellular Respiration
Photosynthesis and Cellular Respiration
energywaterdioxidecarbon oxygensugar
oxygensugarwaterdioxidecarbon energylight
Photosynthesis
Cellular Respiration
What is created in one reaction is used up in the other reaction!
Photosynthesis and Cellular Respiration are Connected
Photosynthesis vs. Respiration video
To Photosynthesize, or not to Photosynthesize, that is the question
• Many organisms cannot photosynthesize (done by plants) they are called consumers– Consumers – an organism that obtains its energy from
consuming other organisms
• To obtain usable energy from food, consumers undergo cellular respiration.
THEREFORE…..
Photosynthesis and Life
• We completely rely on the Sun!
• No Sun = No Photosynthesis = No Food for plants = No Food for animals = No food for larger animals
• No Sun = No life on Earth
• This is the basis behind the dinosaur extinction
Dinosaur Extinction• A HUGE asteroid is thought to
have hit Earth near Mexico 65 million years ago which sent up so much dust that it actually blocked the Sun for many years.
• No Sun = No Food = No more dinosaurs