Second Exam Flashcards
What do lipids do in cells?
Used as secondary energy sources
Major component of membranes
Why are lipids used for energy?
High energy to weight ratio
Harder to metabolize
What are triglycerides?
Storage lipids like fats and oils that consist of a glycerol bound to three fatty acids
What are fatty acids?
Long hydrocarbon chain with a carboxylic head
What are the two forms of fatty acids?
Saturated and Unsaturated
What are ester bonds?
The bond between the hydroxyl of a glycerol and the carboxyl of a fatty acid
What form do saturated fatty acids take?
Solid
What form do unsaturated fatty acids take?
Oils, liquid
What are phospolipids?
Glycerol ester bonded to 2 fatty acids and a phosphate group which is bound to a variable hydrophilic molecule
What is the cystol?
Aqueous part of the cytoplasm of the cell
What is the lumen?
Extracellular space
How does hydrocarbon tail length effect fluidity?
The shorter the tail, the greater the fluidity
How does unsaturation effect fluidity?
Unsaturated means more fluidity
What do sterols in membranes do to fluidity?
Decrease it
How does temp effect fluidity?
Fluidity increases with temp
Where are new phospholipids made?
Cystolic side of smooth ER membrane
What are scramblase enzymes?
Randomly moves phospholipids to even out the membrane
What does flippase and floppase do?
Move specific phospholipids to different sides of the layer
What are the membrane proteins?
Transporters
Anchors
Enzymes
Channels
Receptors
What are integral proteins?
Tightly associated with membranes, some embedded, sometimes transmembrane, and commonly are alpha and beta folded
What are peripheral proteins?
Loosely associated with membrane, may be linked to other substances
What are glycolipids?
Lipid tails attached to a sugar head, the head is exposed to the cell exterior
What are proteoglycans?
Proteins attached to long chains of repeating sugars
What are glycoproteins?
Proteins attached to short, highly branched sugar chains
What is glycocalyix?
Sugar coating of plasma membrane, promotes biofilm formation
What is a cell cortex?
specialized layer of cytoplasmic proteins on the inner face of the cell membrane
What is spectrin?
Protein that lines the intracellular side of the plasma membrane
What can cell cortex abnormalities result in?
Anemia
What can move through semi-permeable cell membranes?
Small nonpolar molecules and some uncharged polar molecules
What can not move through semi-permeable cell membranes?
Charged molecules and ions