2.9 Photosynthesis Flashcards
What is photosynthesis?
Tthe process by which cells synthesize organic molecules (e.g. glucose) from inorganic molecules (CO2 and H2O) in the presence of sunlight.
Photosynthesis as an energy conversion in carbon compounds (carbohydrates, lipids, and proteins).
light energy = chemical energy
seperating photosynthetic pigments by chromatography
X-rays and ultraviolet radiation
- shorter wavelength
- high energy
Radio wave and infrared radiation
- longer wavelength
- low energy
What is the range of wavelengths of visible light?
400 to 700 nanometers
What is the shortest and longest wavelength?
Violet is the shortest and red is the longest wavelength.
What pigment do photosynthesizing organisms use?
Chlorophyll
Why do all various types of chlorophyll appear green to us? what is the reaosn behind the main colour in ecosystems being dominated by plants being green?
- b/c red and blue light is very affectively absorbed while green light is less effective and therefore the green light is reflected
Absorption and actrion spectra
How is oxygen produced in photosynthesis from the photolysis of water?
- photolysis = is the seperation of H2O molecules to release electrons needed, only happens in the light
- H2O = (4e-) + (4H+) + O2
- O2 generated un photosynthesis comes from photolysis, as a waster product it diffuses away
effects of photosynthesis on the earth
Why is energy needed to produce carbohydrates and other carbon compounds from carbon dioxide?
- via photosynthesis plants covert CO2 and H2O into carbohydrates (carbon dioxide + water = carbohydrate + oxygen)
- energy is required for this process, which is obtained by absorbing light
- this energy does not dissapear in the conversion of CO2 into carbohydrate but is converted into chemical energy in carbohydrates
What are the 3 external factors that affect the rate of photosynthesis?
- Light intensity
- carbon dioxide concnetration
- Temperature
controlled variables in limiting factor experiments
