Chapter 6 Flashcards
(25 cards)
Assimilation
the process of converting carbon into living tissue
Heterotrophs
animals and fungi. Aquire carbon by consuming other organisms
Autotrophs
Get carbon from CO2 and turn it into living tissue
Chemoautotrophs
Convert CO2 into organic matter by using energy derived from inorganic molecules or methane
photoautotrophs
use solar energy to convert CO2 into organic compounds using photosynthesis
Photosynthesis
6CO2 + 12H2O —►C6H12O6 + 6O2 + 6H2O
Light dependant reactions
When chlorophyll (pigment embedded in thylakoids) absorbs photons, it is excited. When it goes back to its ground state, it releases energy that then transfers to other chlorophyll
Light independant reactions
AKA- Dark reactions
incorporate CO2 into sugars
Rubisco
Most abundant enzyme on earth. Catalyzes CO2—►2 3-PGA
When did cyanobacteria emerge?
1.2 bya-480mya
When did simple algae/seaweed emerge?
480-430 mya
when did simple terrestrial plants emerge?
430 mya?
How can rubisco reduce photosynthesis output?
Photorespiration-rubisco fixed carbon(carboxylation) and oxygen(oxygenation). The dual function competes with itself
Photorespiration
oxygenation and carboxylation of rubisco compete
net photosynthesis
gross photosynthesis-respiration
fermentation
a type of anaerobic respiration that occurs in the absence of O2. Produces lactic acid
too much light is bad because….
increasted temperature means plants require more water
osmotic potential
measure of decrease in water potential due to an increase in solutes (osmosis drives movement of water into cells)
pressure potential
tugor- force exerted on walls (positive value in living cells)
matric potential
tendancy of water to stick to surfaces. Lowers overall water potential
What are some common plant stressors?
- UV light, too much or too little
- water- too much or too little
- temperature- too hot, too cold
Plant adaptations to drought
wilting(loss of tugor), chlorosis(limmited chlorophyl production), death
What are some ways plants may regulate stomata?
prevent water loss,
