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What are some inhibitors of photosynthesis electrontransport?
DCMU - steals electrons, blocks transport from PSII to PQ
Atrazine (Herbicide) - Block transport from PSII to PQ
DCIP - Artifical electron Acceptor, steals electrons from PQ
Paraquat - "steals" electrons from PSI so NADP+ is not reduced to NADPH (Herbicide)
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Why does atrazine kill plants and not us?
We don't have PSII in our e transport.
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To make ATP in chloroplasts, what three things do you have to do first?
- Set up electron transport
- Use electron transport to set up the proton gradient
- Use proton gradient to makeatp
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Could you make ATP from electron transport energy alone?
No
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Could you make ATP from the proton gradient alone?
yes
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Do you need electron transport to make ATP in vivo?
Yes
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Do you need electron transport to make ATP in vitro?
No
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Can ATP be made by protons flowing in the CF1 to the CF0?
no, only when the proons goes throught the CF0 to the CF1
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How can you make ATP in vitro?
- 1. put thylakoid membranes in pH=4.0
- 2. Wait until pH=4.0 on the inside (load up on H+ inside because the pHs on both sides will equilibrize.
- 3. Move thylakoids to pH=7.0 and add ADP+Pi (high pH inside and low outside) it will go to equilibirze by flowing protons outward, only now creating ATP because it is moving in the correct direction.
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What provides the energy for ATP synthesis in vivo?
sunlight, electron transport, proton gradient
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What provides the energy for ATP synthesis in vitro?
The protein gradient alone
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Is e transport necessary for ATP synthesis in vitro?
no
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Is e transport necessary for ATP synthesis in vivo?
yes
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What are five different things that can happen to light after it hits a pigment?
- absorbed and emmited as heat
- Emmited as fluorescence (emited at a longer wavelength)
- transmit it (just goes by) (no change in wavelength)
- Passed along to another energy carrier (thats what chloroplasts want)
- Reflect it (colors are reflected)
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Why are isolated pigments (like cholorphyll) fluorescent but chloroplasts aren't?
live cholorplasts want to pass their fluorescence along, dead chloroplasts just keep the fluorescence.
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If a plant absorbs will at a wavelength it is...
it is taking it in.
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If a plant is not absorbing well at a wavelength is is...
Reflecting it
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High energy, short wavelength color is ...
Blue
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Low energy, long wavelength color is..
Red
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Which wavelengths are absorbed best by the pigments?
The wavelenths with the highest absorbance.
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If you shine a green light on green plants what will happen to the plants?
They will die. They do not absorb well in green light
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To pass on a wavelength you need to be able to...
absorb it.
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What is chlorophyll?
A pigment
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What color is carotene?
Orange
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Which wavelengths are absorbed by carotene
anything but orange
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The force to move the proton gradient across the membrane provides the energy to make ATP, this is dependent on...
Membrane Potential
Proton gradient
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What is membrane potential?
The electrical driving force
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What is the proton gradient?
Chemical driving force
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pmf equation
pmf = membrane potential - constant (proton gradient *change in pH*)
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If the membrane potential is relatively constant, the pmf is mainly controlled by the ....
Proton gradient
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What is electrophoresis?
The movement of fully charged (ionic) compounds through a viscous medium by an electric field.
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Compounds must be _____ charged to perform electrophoresis.
fully
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Anode is the _____ pole
Positive
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Anode attracts the ...
anion (negative ion)
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Cathode is the _______ pole
Negative
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Cathode attracts the ..
Cation (positive ion)
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Electrophoresis can be used to...
Separate, purify and identify proteins, RNA, DNA (or anything that can be charged)
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what are the two main types of electrophoresis?
Native gels
Detergents
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Native gel characteristics:
- No detergent added
- Migration is affected by native shape (conformation), size, solubility and charge
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Would pH affect native migration?
It could if it titrated a charge and changed the shape
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Explain how a proteins four main characteristics could affect it's migration in electrophoresis?
The shape - if it's thin or fat, will affect the movement
Size- bigger protein will take a longer time to get to it's respective pole, the smaller one will be faster
Solubility - If it's not soluble it is not going to move
Charge - affect in which direction and how fast it'll move.
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Detergent gel characteristics
The detergent is usually SDS
Detergent added to sample AND gel
Migration only due to size
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The SDS structure is...
Negatively charged headgroup with a hydrophobic tail
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SDS is an anionic _______
Detergent
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SDS-PAGE seperates proteins on the basis of their....
size
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When dealing with SDS-PAGE assume that all of the proteins are ______ and ________ charged and soluble in the presence of SDS
denatured
negatively
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When there is no detergent present proteins can be...
a mess (protein charges could be negative, positive or zero, be in native conformation, depending on pH)
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SDS is an anionic detergent that solubilizes and coats all proteins with a ______ charge.
Negative
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PAGE means...
Polyacrylamide Gel Electrophoresis
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In the presense of SDS, all proteins migrate toward the ________ pole because there are all _______.
Positive
Negative
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in SDS-PAGE proteins of the same size move ....
together through the gel in a band
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in SDS Page large proteins move ______ and end up near the ____ of the gel
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in SDS Page small proteins move ______ and end up near the ____ of the gel
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in SDS-Page, protein bands have to be ______ to be seen.
stained
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The protein bands is SDS-PAGE are stained to be seen and identified by ________ with known standards. (known molecular weights)
co-migration.
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size in SDS-PAGE is expressed as..
Daltons (Da)
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1 kDA = ______ Daltons
1,000 = molecular weight
-
50 kDa = _______ Daltons
50,000 = molecular weight
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