Exam 1- February 19th Flashcards
Phospholipid molecules make up most of the ______ bilayer.
Lipid
The lipid bilayer includes __________ and cardiac glycosides.
Cholesterol
“polar” end means that this highly charged phosphate group is considered
hydrophilic
“non-polar” end means that the two long uncharged carbon chains that form tails is considered
hydrophobic
Phospholipids are ___________, which means they are both water and lipid soluble.
amphipathic
Embedded in the lipid bilayer are membrane _______ which penetrate one or both of the lipid layers.
proteins
Model of individual proteins floating about the lipid bilayer
Singer-Nicholson fluid mosaic model
To move things into or out of the cell or vis-versa
Transport
3 things that are transported
1) Protein pores & gated channels
2) Carrier Proteins or Transporters
3) Na+/K+ ATPase Enzyme proteins
This function of cell membrane proteins is important in immunology & development
Recognition
Recognition surfaces glycoproteins as _______.
markers
Recognition also places antigen-recognition receptors on _______ cells.
immune
One function of cell membrane proteins is to surface protein receptors for hormones, nerve transmitters & other factors; physical stimuli. Which cell membrane protein does this?
Signal Reception
Attach cell to cell
protein junctions
Stick cell to surface for crawling, anchoring, and association of cells into tissues.
Adhesion proteins
Separation of charges/_____ causes a voltage to develop. Especially important in explaining actions of nerve, muscle and hair-cell membranes.
ions
These enzymes are associated with receptor or carrier proteins or alone.
Membrane-attached Enzymes
This gives the cell its shape
cytoskeleton
A ______ is made up of more than 100 ______ ______, connected by ________ _______.
Protein is made up of more than 100 amino acids, connected by peptide bonds.
Shorter chains are called
polypeptides
How many different amino acids are used in human proteins?
21
How many different amino acids can be used in plant proteins?
Up to 26
Several proteins may bind together to form a single large assembly called a
multimeric protein
In multimeric proteins, each protein component is called a
sub-unit
Membranes are ___________ permeable.
selectively
Molecules move through the membrane in different ways, depending whether they are __________ or __________.
Hydrophilic or Hydrophobic
Some molecules may move through a membrane with no added energy, this is known as passive _______ or passive _______.
Passive transport or passive diffusion
Examples of lipid-soluble solutes transported through the phospholipid layer are:
gases, fat-soluble vitamins, fats, and steroid hormones
Examples of solutes transported through pores are:
H+ ion, K+ ion, Cl- ion, urea, and water
Examples of solutes transported by carrier proteins through the membrane:
glucose, other simples sugars, amino acids and nucleic acids
This does not require added energy because it uses thermal energy already present in all molecules with a temperature.
Passive transport
Another term for passive transport is
passive diffusion
When a substance moves by lipid solubility through the phospholipid bilayer it is referred to as a
lipid-soluble solute
Gases (CO2 and 02), the fat soluble vitamins (A,D,E and K), fats, steroid hormones (estrogen, testosterone, cortisol) are all examples of what?
lipid-soluble solutes
Water filled pores are known as
channels
When a substance moves through water-filled pores it is known as a
solute
H+ ions, K+ ions, Cl- ions, urea, and water are all examples of what?
Solutes that can be transported through pores
Glucose, other simple sugars, amino acids and nucleic acids are all examples of what?
Solutes that can be transported by carrier proteins through the membrane
What does not require added energy?
Passive Transport
As a rule of passive transport, the membrane must be _______ _________ to a given substance, this way molecules can pass through the membrane coming in or going out.
Selectively permeable
As another rule of passive transport, passive transport is ____________, meaning that molecules may move in both directions.
bidirectional
One rule of passive transport states that molecules, ions, or atoms always move from _____ concentration to _____ concentration.
high to low
The movement of each species of particle by passive transport is considered _________. For further explanation, the movement of glucose, urea, Na+ ion and glycine would depend on the IN/OUT concentrations of each considered without regard to the others.
separately
The rate of passive transport or passive diffusion of a particular substance is proportional to the permeability factor and to the difference in concentrations on each side of a membrane. This equation looks like….
Rate=PX [X out - X in]
The permeability of water through a membrane is considered equal to
1
1 mole =
6.02 x10^23 molecules/atoms/particles
Water only moves by _______ ________ through membrane pores. Therefore, water only moves from HIGH [H20] to LOW [H2O].
passive transport
NaCl, CaCl2, Na2CO3 are all examples that….
ionize in water
sucrose, glucose, urea and glycerol are all examples that…
will not ionize in water, non-ionizing ions
If a solution is iso-osmotic, the cell neither _____ nor _____, but remains the same _______.
If a solution is iso-osmotic, the cell neither swells nor shrinks, but remains the same volume.
_____ moles of dissolved particles/liter, is ISO-OSMOTIC for mammalian cells (including red blood cells).
0.29
A solution is ________ if the [dissolved particles] is less than iso-osmotic.
Hypotonic
Hypotonic solutions will cause the cell to…..
swell
A solution is ________ if the [dissolved particles] is greater than iso-osmotic.
Hypertonic
Hypertonic solutions will cause the cell to…
shrink
-ase means
enzyme
(Active Transport Example)
This gland is active in iodide ion uptake
Thyroid gland
(Active Transport Example)
This intestine is active in transport of glucose and other simple sugars, amino acids and nucleic acids.
Small intestine
(Active Transport Example)
This organ has a lot of work to do, it is active in the transport of Na+ ions, Cl- ions, K+ ions, H+ ions, glucose, amino acids, Ca2+ ions, and bicarbonate ions.
Kidney
T/F: ALL CELLS exchange Na+ and K+ with Na+/K+ ATPase, these are known as chlorine-potassium pumps.
False, known as sodium-potassium pumps
Within the sodium-potassium pumps, 2 K+ IONS are transported to the _____ of the cell in exchange for 3 Na+ IONS transported to the _____ of the cell.
inside, outside
Passive transport always moves from [high] to [low], but what kind of transport can move from [low] to [high]?
Active transport can move from [low] to [high].
potential to do electrical work (measured in volts)
electrical potential
T/F: Electrical current is the movement of electrical charges (+ or - ions), as they do electrical work (measured in amperes). In cells, the electric current is carried by ions instead of electrons. The current is created when separated positive and negative charges come back together.
True
Opposite charges (ions) attract each other; like charges (ions) repel each other, this is known as the
charge rules
Protein structures in the cell membrane that allow ions or water to pass into or out of the cell
Channels or pores
protein channels through the membrane which can open and close are called Some gated channels open or close with a chemical, electrical or physical stimulus.
Gated Channels
proteins that change shape with a stimulus and open or close the channel
gates
Some gated channels open or close with certain stimuli, what are the three stimuli potentials?
Chemical, electrical or physical stimulus
Chemical Stimulus is considered
ligand-gated
Electrical stimulus is considered
voltage-gated
physical stimulus is considered
pressure-, heat-, etc-gated
separation of membrane to create an electrical potential
separation of charges
electrical potential in all cells during rest (always negative inside relative to outside)
resting potential
inside of cell become more positive relative to outside
depolarization
inside of cell becomes more negative relative to outside
hyperpolarization
the cell returns to its original resting potential
repolarization
a self-propagating, positive (depolarizing) “spike” of current through the membrane, followed by a re-setting to the resting potential (repolarization).
Action Potential
Action potentials only occur in ________ cells.
excitable
Nerve cells, Muscle cells, Fertilized ovum and secretory cells are all cells that ______ _________ can occur in.
Action potential
minimum cell potential above the resting potential to start an action potential
threshold
self-propagating in-rush of sodium ions during an action potential
“Runaway Depolariziation” or “Sodium Cycle”
used to describe the action potential, which, once started, cannot be stopped or charged in size
“All or none”
the process of resetting of membrane potential to resting potential after runaway depolarization
“Repolarization”
movement of action potentials along the cell membrane from one part of the cell to another
“Propagation of the Action Potential”
The movement of action potentials in a myelinated nerve, from one node to the next node down.
“Saltatory Propagation”
