Lesson: Photosynthesis Subject: Biology Grade: 10
Lesson: Photosynthesis Introduction
Subject: Biology
Grade: 9
By: Ali-reza Mobaraki
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Some Terms
• Autotroph- an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.
• Heterotroph- an organism deriving its nutritional requirements from complex organic substances.
• Photoautotroph- any organism that derives its energy for food synthesis from light and is capable of using carbon dioxide as its principal source of carbon
The Basics
• Carbon dioxide + water glucose + oxygen
• Energy for the reaction comes from the sun
• Carbon dioxide is obtained from atmosphere
• Water enters through roots
Plant Cell
• Plant cells have a cell wall
• Photosynthesis occurs in Chloroplast
• Cell respiration occurs in Mitochondrion
• Cell wall provides structural support
Plant cell continued
• Light is absorbed by pigments called chlorophylls
• Chlorophyll reflects (does not absorb) the color green
• Chlorophyll is found within the chloroplast
Cellular Respiration
• Plants also go through cellular respiration
• The opposite of photosynthesis
• Occurs at a higher rate in the absence of light
Absorbance of Light
• Different pigments have different absorbance values
• Maximum absorbance is characterized by peak
• Wavelength of between 500-600 is reflected
ATP
• ATP is hydrolyzed to ADP by loosing terminal phosphate
• This process is highly exergonic
• Exergonic reactions are favor formation of products
Z scheme
• The Z scheme shows the flow of electron
• Photoexcitation occurs first at photosystem 2 then photosystem 1
• Energy for electron excitation comes from the sun
Where exactly does cell respiration occur?
The Chloroplast is where photosynthesis occurs
The cell wall provides structural support
Correct!
Chlorophyll a and b, reflect light at/between what wavelength(s) ?
There is an absorbance peak near 400nm
Chlorophyll a and b don’t have peak absorbance at 300nm
Correct
THE END
