Cell Membrane Flashcards
(26 cards)
Why is a cell membrane often described as a Fluid Mosaic Model?
Fluid - Phospholipids and proteins are able to move freely (diffusion)
Mosaic - proteins scattered throughout
Describe a phospholipid
Phospholipids have a polar (hydrophilic head) and a non polar (hydrophobic) tail.
What affects the fluidity of a membrane?
- If the fatty acid chains are unsaturated the phospholipids are more fluid.
- Longer fatty acid chains result in a less fluid membrane.
- The amount of cholesterol.
Do animal cells or plant cells contain more cholesterol in the their membranes?
Animal cell membranes contain as many cholesterol molecules as phospholipids. Plant cells contain much fewer.
What two types of intrinsic transport proteins are found in cell membranes?
Channel proteins and Carriers proteins
What is the diameter of a cell membrane?
7nm
Branching carbohydrates attached to a lipid form a…
glycolipid
Transport proteins has h_________ interior for interior for i_____ and hydrophilic molecules.
hydrophilic
ions
What is glycocalyx?
A carbohydrates bind to produce glycoproteins and glycolipids on the outer surface of the cell surface membrane where they form the glycocalyx and are involved in cell recognition as cell receptors
What magnification is required to view a cell membrane?
100 000x
Which transporter protein has a fixed shape?
Channel protein
Which transporter protein changes shape?
Carrier protein
What do cholesterol do?
Maintain the fluidity and integrity of the bilayer
Whats structure to phospholipids make when shaken with water?
Micelle
What help maintains the shape of the cell?
The cytoskeleton
Name the three major groups of receptors
Signalling, endocytosis, cell adhesion
What is the polarity of the hydrophobic and hydrophilic region?
Hydrophobic is non polar and hydrophilic is polar
How is cholesterol similar to a phospholipid?
It has a polar head and a non polar region
Longer fatty acids mean…
less fluid membrane
What is the function of transport proteins?
They act as channel and passage ways for ions and polar molecules.
Name the three types of lipids found in a eukaryotic membrane
phospholipids, glycolipids and cholesterol
What do antigens in membranes allow
Cell to cell recognition
Which lipid molecules act as receptor molecules?
glycolipids and glycoproteins.
Where can intrinsic proteins be found?
Found in the inner layer, the out layer, but most commonly spanning the membrane
