photo synthetic organisms
forests plants, protists, kelp, cyanobacteria
leaf structure
-stomata
stomata
microscopic openings on leaves… that open and close to allow exchange of gasses (CO2 diffuses into the leaf, O2 and water diffuses out of leave); they keep things from going out so that they do not lose water (will close during the day and open at night to ensure that they don’t lose water)
thylakoid
- in cholorplast
- green membrane bound disks within chloroplasts contain pigments (ex: chlorophylls)
stroma
thick, sugary gliud around thlyakoids in chloroplasts
pigmenta
molecules in plants, algae, and cyanobacteria that absorb light energy
why do leaves turn color in autumn
-plants stop using chlorophyll
photosynthesis parts
- light reactions (preparing ingredients
2. calvin cycle (making sugars)
Part 1 of photosynthesis
light reactions (photons of energy from light are used)
- split water (separate hydrogen and oxygen)
- sunlight is used to excite hydrogen electrons from water to high energy state (as they fall down to a lower energy state they pass through an electron transport chain where ATP is generated) - occurs on thylakoid membranes
- photons from sunlight excites the electrons a second time (high energy hydrogen electrons are carried to the calvin cycle; has to happen in the day because it requires sunlight)
where does energy come from in cellular respiration to create ATP?
food (sugar)
where does energy come from in photosynthesis to create ATP
sun
part 2 of photosynthesis calvin cycle
glucose is made in the calvin cycle using…
1. CO2 from the air
2. hydrogen electrons (and protons) from the water from light reactions
3. CHO bonded together using the energy in ATP from light reactions
-called carbon fixation
occurs in the stroma
-does not require sunlight
photosynthesis summary
see slide 23
glucose is used for…
cellular respiration, celluluose, starch, and making organic molecules
everything starts with glucose!
greenhouses
- greenhouses used to grow plants in the winter
- solar radiation (sunlight) enters through glass or plastic
- solar radiation heats up the surfaces and air inside (heat rises)
- the glass or plastic traps some of the heat raising the temperature inside (like your car on a sunny day)
greenhouse effect on earth
- solar radiation warms the earth’s surfaces
- greenhouse gases in atmosphere trap some of the heat
- natural process that raises earth’s temperature about 18C or 50F (good thing)
- normally CO2 is .03% in the atmosphere compared to O2 which is %
greenhouses gases include
CO2, water vapor, methane
global warming/climate change
- occurs when too much heat is trapped because of increase in greenhouse gases in the atmosphere
- since the beginning of the industrial revolution, CO2 in the atmosphere has increased about 30% (mostly due to combustion of carbon-based fossil fuels
global wamring
excessive greenhouse effect; can bring about climate change
- not a good thing because it can change our climate, plants and animals do not have time to adapt
temperature change during the 20th century
1.1F
