Plasma Membranes Flashcards
What purpose does the plasma membrane serve?
The plasma membrane serves to protect the living cell from its surroundings.
What property of the plasma membrane allows it to take in nutrients and eject waste?
Selective Permeability allows the plasma membrane to decide what goes in and decide what goes out.
What is the most abundant lipid in the plasma membrane?
Phospholipids are the most abundant lipid in the plasma membrane.
What does amphipathic mean in the context of phospholipids?
Amphipathic that it has both hydrophobic and hydrophilic parts.
What does a Phospholipid bilayer look like?
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What does the fluid mosaic model say?
The fluid mosaic model says that the membrane is fluid and that it has non-randomly placed proteins embedded in it.
Are phosopholipids mobile or immobile?
Phospholipids, according to the fluid mosaic model, drift laterally through the bilayer
Think of a fluid comparable to membranes.
Membranes are usually as fluid as salad oil.
What factors into the fluidity of a membrane?
Factors such as the saturation of the fat in the plasma membrane affect the fluidity of the membrane.
Unsaturated tails prevent packing. Saturated tails pack together.
Remember, unsaturated fats are kinky.
Are membranes made of one or multiple things?
A membrane is a collage of different proteins.
What determines a membrane’s specific functions?
Proteins determine most of a membrane’s specific functions.
What is the difference between Peripheral and Integral proteins?
Peripheral proteins are on the side. Integral proteins penetrate the hydrophobic core…
What are the six major functinos of membrane proteins?
- Transport
- Enzymatic activity
- Signal Transformation (into another form)
- Cell-Cell recognition
- Intercellular joining
- Attachment to the cytoskeleton and ECM
How do cells recognize each other?
Cells recognize each other by binding to molecules on the on the plasma membrane.
Are there differences in the inside and outside of plasma membranes?
Yes.
When is the sidedness of the plasma membrane determined?
When the membrane is built by the ER and Golgi complex
What is selective permeability?
Selective Permeability refers the plasma membrane’s ability to select what it wants to let in and keep out what it wants to keep out.