Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Biology Chapter 8 -
study from notes
| Question | Answer |
|---|---|
| photosynthesis changes light energy into... | chemical energy |
| photosynthesis produces _______ | oxygen needed by most organisms to survive |
| the oxygen produced by photosynthesis forms... | an ozone (O3) shield in the upper atmosphere which filters out the damaging ultraviolet rays of the sun |
| Photosynthesis uses _______ and thereby slows its rate of increase in the atmosphere | CO2 |
| loss of electrons | oxidation |
| oxidation in organic molecules | more C-O bonds and fewer C-H bonds |
| gain of electrons | reduction |
| reduction in organic molecules | less C-O bonds and more C-H bonds |
| when burning wood, carbon in the wood is... | carbon...oxidized (loses electrons) |
| when burning wood, oxygen in the air is... | oxygen...reduced (gains electrons) |
| compromises 0.035% of the atmosphere | carbon dioxide |
| carbon dioxide diffuses through... | ...stomatal pores and goes into solution in the thin film of water on the outside walls of the mesophyll cells |
| the source of electrons used in photosynthesis | water |
| the oxygen released in the atmosphere is a by-product of... | splitting water, not from using the CO2 |
| about 40% of the radiant energy plants receive from the sun is in the form of... | visible light |
| reds wavelength? | longer wavelengths |
| violet wavelength? | shorter wavelengths |
| shorter wavelengths have _____ energy | higher energy |
| longer wavelengths have _____ energy | less energy |
| leaves absorb... | 80% of the visible light that reaches them |
| oxygen production is directly related to... | the type of light that chlorophyll absorbs |
| each chlorophyll molecule contains | one atom of magnesium and a long lipid tail which is anchored into the interior of a thylacoid membrane |
| absorbs the energy from visible light, especially red and violet (green is reflected) | chlorophyll |
| the energy absorbed raises an electron in chlorophyll from | a relaxed state (low energy) to an excited state (high energy) |
| as the electron falls back, it can be used to | do work (move things, build things) |
| simplest system (not very efficient) | cyclic pathway |
| what happens in cyclic pathway? | the excited electron falls back to its original position and is reused as it falls, its energy is stored by making an ATP molecule |
| ATP | (Adenosine triphosphate) the 3rd phosphate takes a lot of energy to put on and releases energy when it comes off most systems in a cell that require energy use ATP |
| ATP- stable or unstable? | very unstable, short life at room temperature |
| complicated but more efficient | non-cyclic pathway |
| what happens in non-cyclic pathway? | uses 2 photosystems, electrons are not recycled |
| Photosystem II | absorbs a proton of light one electron is excited (<-- H2O is consumed) |
| H-O-H -----> O=O | oxidation |
| O2 and H+ are produced as byproducts inside the ... | thylacoid space |
| handout | process creates a high concentration of H+s inside the thylacoid |
| chemiostatic theory | ATP synthesis is driven by protons rushing out of the thylakoid space into the stroma |
| as protons rush out, they go through... | ...they go through ATP synthase |
| ATP synthase | uses the osmotic pressure of the protons to drive the synthesis of ATP |
| the electron "falls" from the cytochrome complex to... | ...Photosystem I |
| Photosystem I absorbs... | absorbs a second photon of light |
| In Photosystem I: | electron is made even higher in energy; the high-energy electron is passed to NADP+ reductase; NADP+ reductase uses the energy in the electron to make NADPH; NADP+ +2 electrons ---> NADPH (reduction) |
| NADPH is a _____ molecule | high-energy molecule |
| NADPH is more _____ than ATP | more stable, but only lasts a few hours (it's used mostly for building other molecules) |
| Calvin cycle or | dark reactions (light independent reactions) |
| Calvin cycle (dark reactions) | high energy electrons in NADPH and energy from ATP are used to make CO2 into sugars; CO2 + H+ = electrons ---> [HCOH]; still easy to get the energy back if you need it |
| sugars are much more _____ than ATP or NADPH | stable (sugars=simple carbohydrates) |
| CO2 fixation is... | complicated |
| CO2 is "fixed" to an activated... | 5-carbon sugar (RuBP) to make a 6-carbon sugar |
| 6-carbon sugar immediately splits into | two 3-carbon sugars (PGA) |
| both (PGA) are reduced using ATP and NADPH to (PGAL)<-- high energy product | both (PGA) are reduced using ATP and NADPH to (PGAL) |
| CO2 fixation (more info) | three rounds of this gives 6, 3-carbon sugars (18 carbons); 5 3-carbon sugars (15 carbons) are rearranged using ATP to give 3 5-carbon sugars (RuBP) to regenerate the cycle |
| CO2 fixation (more info...) | the sixth 3-carbon sugar is net gain; every 3 turns of the cycle produces 1 3-carbon sugar |
| 3-carbon sugars can be used to make: | carbohydrates (sugars)-- monosaccharides (single sugar units) |
| Glucose | most widely usable sugar; only sugar that brain cells can use |
| disaccharides | (two monosaccharides linked by loss of water); like maltose |
| Polysaccharides | many monosaccharides linked; starch cellulose (plant structure) |
| linking many sugars into one big molecule means you need _____ water to dilute it | less (less osmotic pressure) |
| Fats even more reduced than... | sugars |
Created by:
chelsea_2010
Popular Biology sets