Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
Structure and Importance of the
Membrane
Q. How do you know that membranes are compsed of two layers of lipips, not just one?
A. 1. Gorter and Grendel first purified membrane lipids from red blood cells. They choose these cells because they lacked internal membranes, making it possible to isolate plasma membrane lipids exclusively. By estimating the number of starting cells and the surface area of each cell. The physiologists were able to calculate the total area of membrane they had purified.
2. By dissolving the erythrocte lipids in benzene, then evaporating the benzene over water, Gorter and Grendel were able to create a lipid monolayer on a water surface.
3. Finally, Gorter and Grendel measured the are of the monolayer they had created. They found that the area of the monolayer was twice the estimated area of the starting membranes, implying that the original membranes were composed of two layers of lipids, or a lipid bilayer.
Q. _____are the primary determinates of membrane structure, while ______ carry out membrane functions?
A. Lipids, proteins
Q. Which two inernal membranes are one and the same?
A. The outer nuclear membrane and the endoplasmic reticulum membrane are really one and the same.
Q. Across which cellular membranes do ion gradients exist, and what kinds of functions do such gradients serve?
A. Ion gradients exist across most cellular membranes. One use for these ion gradients is to store and convert energy. Another use for ion gradients is to transduce signals.
Q. Amphipathic molecules have both polar (hydrophilic) and nonpolar (hydrophobic) parts. Can you think of the most polar and least polar types of bonds found commonly in biological systems?
A. Polar bonds commonly found in biological systems are carboxyl, amino, and hydroxyl. Carbon-Hydrogen bonds are barely polar and the carbon-carbon bond isn't polar at all.
Q. Can you list the molecular components common to all phosohoglycerides?
A. Phosphate, glycerol, and two fatty acids.
Q. List the molecular components common to all phosophoglycerides.
A.Phosphate, Glycerol, and two fatty acids.
Name three classes of membrane lipids. [also stare shich is the most common class.]
A. Glycolipids, cholesterol, phospholipids [Phospholipids]
Q. This picture is taking liberties. Can you guess how?
A. Actual lipid bilayers are self-sealing, meaning that is aqueous solution,"edges" are rapidly eliminated. The force behind this process is the same hydrophobic effect that formed the bilayer in the first place.
Q. Which common household product is composed of molecules whose function depends on their amphipathic nature?
A. Soap is made up of fatty acids, which are amphipathic.
Q. What type of bonding dominates interactions between lipid tails and limits fluidity?
A. Van der Waals forces
Q. How could you identify a transmembrane helix just by examining the amino acid sequence of a protein?
A. Transmembrane helices can often be identified from a protein's sequence as characteristic stretches of two-dozen or so hydrophobic amino acids.
In class we researched Fluid Mosaic Models and made a poster to represent what we have learned. By doing this it helped me to be able to identify different parts of the model. Overall I feel like I have a good knowlege with membranes and their structures.
The poster we made in our group
The end
The fatty acids "tails" in phosphoglycerides usually have an even number of caron atoms.