C1.3 Photosynthesis Flashcards
(17 cards)
What are the 2 major steps of photosynthesis?
- light dependent reaction (photolysis) : produces carbon dioxide
- light independent reaction: produces glucose
Which colour has the shortest wavelength?
Violet
What colour has the longest wavelength?
Red
Why do leaves look green?
- Because they reflect green light and other lights
- chlorophyll absorb other lights more & reflect green light the most
What is an action spectrum?
A plot of the overall rate of photosynthesis against the wavelength of light
What experiment can be used to separate different pigments in chloroplast?
Paper chromatography
What is the formula for the Rf value
distance moved by the compound / distance moved by solvent
How to conduct a chromatography experiment
- Crush leaves using propanone / acetone to dissolve pigment out
- Place spot of pigment solution at the bottom of the chromatography paper
- Dip it in solvent
- As solvent passes through, it will separate the pigments
- Calculate Rf Value
What is another experiment that is similar to paper chromatograhy?
Thin paper chromatography
Which is test gives better results paper chromatography OR thin layer chromatography
Thin layer chromatography - well defined, well separated spots
What is a limiting factor?
A factor that restricts the rate of a reaction when present in a low amount
What are some limiting factors in the rate of photosynthesis?
- temperature
- light intensity
- carbon dioxide concentration
What are the 2 carbon dioxide enrichment experiments?
- enclosed greenhouses
- Free-air carbon dioxide enrichment experiments (FACE)
How does a enclosed greenhouse work? What is measured?
- carbon dioxide levels are elevated by burning fossil fuels
- all other condition are controlled
- total biomass produced is measured OR yield of the fruits or vegetables grown
What is the limitation of an enclosed greenhouse experiment?
Done in controlled conditions = don’t reflect those that occur in the natural environment
How does the FACE experiment work?
- carbon dioxide is released around a circular area between 1m and 30m in diameter
- pipes surround the area & release carbon dioxide continuously
- sensors within the area monitor carbon dioxide levels
- total biomass produced could be measured OR yield of the fruits or vegetables grown
What is the limitation of the FACE experiment?
Very expensive!!!
Some conditions cannot be controlled
