Lecture 14 - Membrane Structure (Ch 11) Flashcards
Describe the tail part of a lipid
uncharged, nonpolar, hydrophobic
In osmosis, how does water move through concentration gradients?
Water moves from areas of low to high solute concentrations
Cholesterol is ideal for what situation?
When temperatures drop, cholesterol helps phospholipids to be properly spaced; they also prevent being too fluid in room temps
Peripheral proteins are found on either layer of the membrane , T/F?
True- but one, not both for each one
Integral proteins typically hold what job
They can be transporters or channels
Glucose molecules are too big and polar to cross the cell membrane by themselves, true or false?
True; they rely on integral proteins
Glycoproteins and glycolipids allow you to
recognize and signal other cells!
Which glycoprotein is found by HIV to infect cells? but usally this glycoprotein is for..
CD4; cell immunity
The most abundant phospholipid in the membrane is
phosphatidylcholine
Galactocerebroside is a typie of ___
glycolipid
What is an example of hydrophilic molecules attracting water molecules
acetone
What is an example of hydrophobic molecules avoiding water? Describe the process
2 methylpropane; water makes a cage around 2 methylpropane to max out h bonding duudeee
How do phospholipids repair themselves?
By spontaneous rearrangment of phospholipids, you can heal the membrane if it tears or holes
Which conformation of the membrane is energetically favorable?
the ball shape (enclosed) comes out on TOP compared to the flat one
What has the highest influence of membrane curvature?
The lipid hydrophilic head
What type of movement barely happens in the bilayer?
Flipflopping lipdis
What movements happen usually in bilayers?
Flexion, rotation, and lateral diffusion
How do lower temperatures affect phospholipid compositions in MICROBES?
Low temp makes the phospholipids have more double bonds and shorter tails (more fluid)
How do higher temperatures affect phospholipid compositions in MICROBES?
High temp makes phospholipids have single bonds and longer tails (less fluid)
-% of membrane lipid content is cholesterol; where does it fit in?
20%; in spaces left by unsaturated fats’ kinks
Why is important to have a fluid membrane mosiic modelas dadalsdkjalsd?
For cell signaling, cell division, fusing membranes, and distributing proteins after they are made
Where does membrane synthesis begin? On which surface?
the ER; on the cytosolic side
Which ones random: flippase or scramblase?
scramblase
What are the steps to making a membrane?
Phospholipds areDEPOSITED into cytosolic side of ER, then FLIPPED to noncytosol side using enzymes
