Introduction to photosynthesis Flashcards
What does photo mean?
light
what is photosynthesis?
It is the process whereby light energy from the sun is transformed into chemical energy and used to synthesise large organic molecules from smaller, inorganic substances
what does synthesis mean?
Making something
what is the chemical equation for photosynthesis ?
6C02 + 6H2O -> C6H12O6 + 6O2
what is the equation for photosynthesis ?
Carbon dioxide + water -> glucose + oxygen
What is Van Helmont’s experiment ?
- He grew a willow tree in a tub for 5 years
- weighted the mass of the tree and the soil in the beginning and end of the experiment
- this demonstrated that something is being incorporated into the biomass of the tree causing it to increase its mass
- the substance is not being derived from soil
What did Van Helmont conclude?
- That the increase in mass was the mass of the added water.
- This is partly true but later it was shown that carbon dioxide was also contributing to the increase in mass
So why did some of the soil gain mass in Van Helmont’s experiment?
- in order to make proteins it is necessary for the plant to accquire nitrogen in the form of nitrates.
- these are obtained from the soil along with other minerals which accounts for the slight loss of mass from the soil noted after 5 years
Is a willow tree a hetertroph or autotroph? Why?
- heterotroph
- energy was required for the conversions of small in organic molecules into larger organic molecules.
- energy was in the form of light
what happens to energy releases by the oxidation reactions?
it is used by the bacteria to manufacture their own food
what happens to the nitrates absorbed by green plants?
- Nitrogen is incorporated by green plants and nitrogen is incorporated into nitrogen-containing organic compounds
what is an electron transport chain?
electrons flowing through proteins in a membrane
