BIO TEST 3 - LECTURE 2 STUDY GUIDE Flashcards
Which statement does not describe a reason why the lipid bilayer of your membrane can be called “fluid?”
The word “fluid” implies movement, and this is true for the cell membrane, as the components are floating around, they’re not static.
The fluid mosaic model was created by Singer and Nicolson in 1972. That stated that the cell membrane is composed of a phospholipid bilayer. Which statement describes one of the functions of this lipid bilayer?
Lipid bilayer is a barrier
The fluid mosaic model was created by Singer and Nicolson in 1972. That stated that the cell membrane contains transmembrane proteins. Which statement describes one of the functions of these transmembrane proteins?
Transmembrane proteins- transport of substances and information across the membrane.
trans means transport
The fluid mosaic model was created by Singer and Nicolson in 1972. That stated that the cell membrane contains an interior protein network. Which statement describes one of the functions of the interior protein network?
interior protein network- membranes are structurally by intracellular proteins that reinforce the membrane’s shape.
The fluid mosaic model was created by Singer and Nicolson in 1972. That stated that the cell membrane contains cell surface markers such as glycoproteins and glycolipids. Which statement describes one of their functions?
Glycoproteins
-form the extracellular matrix
Glycolipids
-are used to identify and also protection
Recent findings have discovered the plasma membrane is not homogeneous and contains microdomains with distinct lipid and protein compositions. These portions of the cell membrane are called _______________ and are heavily enriched in cholesterol and saturated fatty acids which makes it “thicker” than other areas of the plasma membrane. Fill in the blank.
Lipid Rafts
Which statement describes a possible function of a lipid raft?
Heavily enriched in cholesterol and saturated fatty acids which makes it “thicker” than other areas of the plasma membrane. Lipid rafts are harder to dissolve by non-ionic detergents.
Proteins within the plasma membrane can be multifunctional. Which statement does not accurately describe the function of different transmembrane proteins?
Transmembrane proteins- transport of substances and information across the membrane.
trans means transport
What is the definition of simple diffusion?
SIMPLE DIFFUSION
** - Net movement of substances from high to low concentration with no energy used**
- LINEAR INCREASE
-SOLUTES MOVED ALONG A CONCENTRATION GRADIENT IN A SOLUTION
-SOLUTES MOVED ALONG A CONCENTRATION GRADIENT IN A SEMIPERMEABLE MEMBRANE
Which type of molecules can easily go and pass through the phospholipids bilayer of your cell membrane during simple diffusion (i.e. which type do not need a carrier or channel)?
small nonpolar
In order to diffuse many different ions and larger molecules across the plasma membrane, your cell must use protein channels and carriers. Why is this the case (the definition of an ion channel we discussed in class is the hint)?
Ion Channels
- Possess a hydrated interior that spans the membrane.
What is the definition of passive transport? (hint…why is it called passive?)
Passive Transport
- Something that does not require energy in any way, shape or form
How is the direction of the net movement of molecules determined when simple diffusion is occurring? (hint…there are two answers we discussed in class)
Gases, hydrophobic molecules (must be small), small polar uncharged molecules
Which statement does not describe one of the three characteristics of facilitated diffusion?
Facilitated Diffusion
-is when you have to use carriers and channels to send things through
According to the video Diffusion, a concentration gradient is itself a form of _______________ energy. Fill in the blank.
Potential
