CHAPTER 7 - Plasma Membrane Flashcards
Define the plasma membrane and its function.
- The P.M separates a living cell from its surrounding.
- A thing barrier that controls traffic in and out of the cell.
What does selective permeability mean?
Certain substances cross the membrane more easily than others.
What macromolecules are found within the membrane?
lipids, proteins, and carbohydrates
Most abundant lipid
phospholipids
What is the term for a phospholipid that is hydrophobic and hydrophilic?
Amphipathic molecule
A membrane’s fluidity is based on its chemical makeup. Membranes rich in unsaturated fatty acids are more _____ than those with saturated fatty acids.
- FLUID.
- Saturated fats are solid, where as unsaturated fats are liquid.
A membrane’s fluidity is based on its chemical makeup. Membranes rich in unsaturated fatty acids are more _____ than those with saturated fatty acids.
- FLUID.
- Saturated fats are solid, where as unsaturated fats are liquid. Due to the kinks at the bonds of saturated fats.
At what temperature does cholesterol restrains movement of phospholipids and reduces its fluidity.
ACTS AS A BUFFER
WARM.
- At cool temp, it allows its fluidity.
What’s a key role of cholesterol in phospholipids?
Acts as a buffer, maintains and restrains the movement of the phospholipids.
Membranes have multiple proteins - 50 diff types of proteins in RBC.
Proteins determine a membranes function.
What are the two major membrane proteins?
Integral membrane proteins and Peripheral Proteins
Peripheral proteins are found where?
Often bound loosely to the surface or on integral membranes.
Integral proteins are found where?
It spans across the membrane.
What are important functions of membrane proteins?
Transport, enzymatic activity, signaling, transduction, recognition, intercellular joining, and attachment to cytoskeleton.
Membrane carbohydrates provide a tag/ID. Where are they found?
On the extracellular/surface of the cell.
Which molecule is varied and found on the surface of the cell?
Membrane Carbohydrates
What assist in cell to cell recognition?
Carbohydrates
What is the difference between glycolipids vs glycoproteins?
- Carbs + proteins
- Carbs + Lipids
What are the two types of transport? What are the differences between them?
- Active transport requires energy to go past the membrane/concentration gradient.
- Passive transport moves down the concentration gradient. Does not require energy to pass.
What determines the type of transport used?
The concentration gradient
Define diffusion.
Diffusion is the tendency of molecules to spread out evenly in an available space.
What is the concentration gradient?
The difference between the concentration of a substance on either side of a membrane.
TRUE OR FALSE: An isotonic solution has no water movement across the membrane.
TRUE.
- An isotonic solution Is flaccid, the solute concentration is equal as that inside the cell.
What is a hypertonic solution?
Hypertonic solutions has a higher solute concentration than inside the cell - causing the cell to lose water and shrivel.
(Flaccid)
