Chptr 5 Membrane Strucute and Function Flashcards
Na
Components of the plasma membrane
Phospholipid bilayer, Protein Molecules, Cholestrol
What does cholesterol do in the plasma membrane
Modify thr fluidity of the membrane over a range of temperatures
The heads of the bilayer are hydrophobic or hydrophilic
Hydrophilic
The tails of the plasma membrane are hydrophobic or hydrophilic
Hydrophobic
What is attached to the heads of the plasma membrane?
Carbohydrate Chains
What is attached to the tails of the plasma membrane?
Cytoskeleton Filaments by membrane proteins
A molecule that contains both a hydrophobic and hydrophilic region is called?
Amphipathic
Ways to study the surface of membrane proteins . (2)
Electron Micrograph & freeze-fracture
Method which spilts the membrane into an upper and lower layer by freezing.
Define: Integral & Peripheral Proteins
Integral embedded into the membrane
Peripheral occur only on the cytoplasmtic side of the membrane
Phospholipids have an attached carbohydrate chains are called:
Glycolipids
Phosphoproteins that have an attached carbohydrate chain is called:
Glycoprotein
Glycocalyx
Carbohydrate chains attached to giving the cell a “sugar coat” this provides protection, cell - cell ahdesion, reception of signaling molecules, cell - cell recognition.
Allows particular molecule or ion to cross the plasma membrane freely.
Channel Protein
Selectively interacts with specific molecules or ions so that it can cross the membrane plasma.
Carrier Protein
The major MHC ( Major Histocompatibility Complex) These glycoproteins are different in each person and responsible for rejection after surgery
Cell recognition
Shaped in such a way that specific molecules bind with them.
Receptor Protein
Which connections hold a membrane protein in place.
ECM extra cellular matrix
Cytoskeleton
What gives cells unquie identification?
Carbohydrate chains
What is the basis for the blood groups
Carbohydrate chains
These membrane proteins catalyze a specific reaction
Enzymatic proteins
Join cells so that tissue can fulfill a function
Junction Proteins
These protiens recieve a substance and change their shape, this change moves the substance across the membrane.
Carrier Protein
Are glycoproteins, one function is to recognize when the body is being invaded
Cell recognition proteins
Have a shape that allows only a specific molecules to bind to it.
Receptor Proteins
These protiens carry out metabolic reactions directly
Enzymatic Proteins
3 steps in Cell Signaling
- Receptor: Binds to signaling molecule, activated and initiates
- Transduction pathway: Series of relay proteins that ends when protein is activated
- Response: Targeted protiens bring about a cellular response.
Which type of substances can pass through the bi layer without energy, Why?
Hydrophobic, because they are similar to the center of the layer
Which type of molecules expend energy to cross the bilayer?
Hydrophilic
Passage of molecules into and out of the Cell
Diffusion: Concentration gradient, Requirement to Pass, Example
Towards lower, Concentration Gradient, Lipid-Soluble Molecules & Gases
Passage of Molecules into and out of the Cell
Facilitated Transport: Direction, Requirement, Example
Toward lower concentration, Channel or Carrier and Concentration Gradient, Some sugars & Amino acids
Passage of Molecules into and out of the Cell
Active Transport: Direction, Requirement, Example
Towards higher concentration, Carrier plus energy, Sugars / Amino Acids / Ions
Passage of Molecules into and out of the Cell
Bulk Transport: Direction, Requirement, Example
Toward outside or inside, Vescile utilization, Macromolecules
Why can water pass through the cell so easily
Aquaporins
Diffusion
Movement of molecules down their concentration gradient
A solution contains both a _____ and a ______
Solute and a solvent
Relative solute concentration of 2 environments separated by a semi permeable layer
Tonicity
If a solution is hypotonic to a cell what happens to the cell. What if the solution is hyoertonic
Hypo water goes in
Hyper water goes out
What is the tonicity for an IV?
0.9 NaCl
What is the bursting of a cell called
Lysis
A plant cell placed in a hypotonic solution what will happen
Vacuoles fill with water turgor pressure developes, chloroplasts are seen next to the cell wall.
The process in which a cell shrivels
Crenation
The process of water leaving a plant cell is called
Plasmolysis
The term _____ refers to a cell that has been exploded due to osmotic pressure.
Cytolysis
_____ is the term used to describe cytolysis in red blood cells.
Hemolysis
_____ is determined by the water content of the vacuole
Turgor Pressure
Why do plants wilt?
Lack of Turgor Pressure to keep the plant erect
Solution that causes a cell to shrivel is
Hypertonic
A solution that causes a cell to take in water is
Hypotonic
What kind of transport are Carrier Proteins responsible for?
Facilitated and active transport
Use of a plasma membrane carrier protein to move a molecule or an ion from a region of lower concentration to one of higher Requires Energy
Active transport
In the sodium potassium pump which is moved outside the cell? Which is moved inside
Sodium Na+ outside
Potassium K+ inside
How do large molecules, protiens, polysaccharides, or nucleic acids enter or exit the cell?
Membrane vesicles
Substances exit the cell via
Substances enter the cell via
Extcytosis
Endocytosis
3 types of endocytosis
Phagocytosis
Pinocytosis
Receptor mediated
What is a secretory vesicle?
Used in exocytosis to expell large molecules out of the cell
What are secreted during exocytosis
Hormones, neurotransmitters, digestive enzymes
When an endocytic vesicle fuses with a lysome, what occurs
Digestion
Two types of passive transport
Diffusion and osmosis
Does facilitated transport require energy
No
What kind of proteins help in facilitied difuson
Channel or carrier
Facilitated trasnport moves how long the concentration gradiente
From low to high
