MT2 showdown Flashcards
How many photons, NADPH, and ATP needed per a CO2 fixed
photons: 9-10
NADPH: 2
ATP: 3
How do guard cells open and close? (SR scheme with 5 parts)
1) blue light receptor recieves signal
2) proton pump starts pumping protons out of the cell, causing hyperpolarization
3) VG K+ channels open and cause K+ to enter the cell
4) charge is balanced by malate and Cl-. This lowers the water potential
5) lower solute potential –> water uptake into vacoule –> stomatal opening
How does water get into the roots
1) proton pumps lowers the pH of the soil around the roots
2) Ions are taken up by either passive transport (possitive ions) or secondary active (negative ions)
3)ions either move symplastic or apoplastic (along the outside of the cell membrane
4) casparian strip stops the apoplastic flow of ions
What is the formula for ion potential
mu= mu* + RTlnC +zFE +VP
Nerst equation (and assumptions)
Delta E = Ei- Eo = 60log(Co/Ci)
Assumption: 25 degrees C, univalent ion
What is the difference between amylose and amylopectin? What enzymes do they use?
Amylose: linear carb chain. Uses the enzyme startch synthase to form 1-4 link
Amylopectin: Branched carb chain. Uses the enzyme branching enzyme to form 1-6 link
(either way, sugar must be primed with ADP-glucose pyrophosphorylase)
What two ways sucrose can make it into glycolysis (hexose phosphate pool)? Which is reversable
-Invertase: enzyme can add H20 to sucrose to turn it into glc and fructose
-sucrose synthase: Enzymes adds a UDP to sucrose to turn it into fructose and UDP-glc. Reversable
What two enzymes phosphorylate sugars? which one can phosphorylate UDP-glc? Which one is reversable?
Hexokinase: phosphorylates any triose. Irreversable
UDP-glc pyrophosphorylase: only phosphoryates UDP-glc. reversable
Which enzyme removes sugars from amylopectin? How about amylose?
Amylopectin: maltose is removed my endoamylase in low pH. Debranching enzyme is needed otherwise
Amylose: can be broken into short chains by startch phosphorylase, and then to glc
What is the glyoxylate cycle? What does it do and what is it similar to? Does it produce CO2, NADH, or FADH2. Where does it occur?
GXC can make lipids into sugars. Mirrors TCA cycle (input is 2 Acetyl-CoA per one succinate) and gives out a succinate for use and a glyoxylate as regenerative material
-Doesn’t produce CO2 or any electron carriers
-Important enzyme (different from TCA) is isocitrate lyase (isocitrate to succinate and glyoxylate)
-Occurs in glyoxysome
What does the Caspian strip do?
Allows for selective transport and concentration of ions into the xylem
What are the three difference between xylem and phloem?
Xylem:
- carries water, minerals, and ions
- one way transport
- dead, lignafied tracheary cells
Phloem
- carries photosynthate
-multidirectional
-smaller, living cells
What do companion cells do?
Companion cell do protein, ATP synthesis, and photosynthate loading
What do parencymal cells do?
They store and release food
What are the two forms of plugging up damaged sieve elements
Short-term: P-proteins plug the pares
long-term: callose plug
