Biomembranes II (Lecture 8) Flashcards
______ can be used to solubilize lipids
and membrane proteins.
Detergents
_____ contain a charged group and tend to denature proteins.
Ionic detergents
______ detergents lack a charged group and can extract protein in active form .
Non-ionic detergents
WHat are the two types of ionic detergents?
Sodium deoxycholate Sodium dodecylsulfate (SDS)
What are the two types of non-ionic detergents?
Triton X-100
Octylglucoside
______ proteins purify and biochemically characterize as-is.
Soluble
______ proteins are most soluble in water; remove from membrane with high salt concentration to disrupt ionic bonds or with divalent ion chelators (eg. EDTA)
Peripheral
______ proteins might remove anchor and study as a soluble protein.
Membrane-anchored
______ membrane proteins are hydrophobic membrane-spanning regions tend to aggregate and precipitate when removed from membranes; need to solubilize with non-ionic detergent
Integral
______ is caused when the concentration is above the CMC and you cannot interact with the protein
Micelles
Light energy capture occurs in ______ of chloroplasts
Thylakoid membrane
The soluble portion of the chloroplast is the ______.
Stroma
The interior of the thylakoid vesicles is the ______
Thylakoid lumen
What is the difference between chlorophyll a and chlorophyll b
CHO group for b instead of methyl group for a
What are the four stages of photosynthesis?
- Light absorption, generation of high-energy
electrons, and O2 formation from H2O
Photosystem core proteins maintain chlorophyll in orientation & position optimal for light absorption - Electron transport leading to reduction of NADP+ to NADPH and PMF generation
- Synthesis of ATP
- Carbon fixation (conversion of CO2 into carbohydrates)
You attempted to isolate chloroplasts, and tested the results using DCPIP. If purification of chloroplasts was ineffective, so that there was very little PSII present, what result would you expect?
DCIP would remain blue
True or False: For fatty acid biosynthesis, you always need an even number of carbons from 14-20 carbons for phospholipid and 26 carbons for sphingolipids.
True
______ are fatty acids have no carbon-carbon double bonds (saturated with hydrogen) and ______ are fatty acids that DO have at least one carbon-carbon double or triple bond.
Saturated, unsaturated
Unesterified fatty acids (not linked to CoA) are transported by ______ in the cytosol.
Fatty acid binding proteins (FABP)
Where can active FABPs be found?
Adipose tissue and active muscle
Where are phospholipids synthesized?
Cytosolic face of ER membrane (usually smooth ER)
______ is made in the ER from palmitoyl CoA and serine.
Sphingolipids
Where is cholesterol usually made?
Animal cells only, mainly in liver, ER cytosol and membrane
What are the 3 types of lipid transport between organelles?
Vesicle transport
Membrane “bridges”
Lipid-transfer proteins
What are the 4 types of lipoproteins that transfer larger fats in the bloodstream.
Chylomicrons
Very low density lipoproteins (VLDL)
Low Density lipoproteins (LDL)
High-density lipoproteins (HDL)
What type transfers the most triglycerides?
Chylomicron
WHat type transfers the most protein?
HDL
WHat type transfers the most cholesterol
LDL
Where are most lipids synthesized?
Liver
