S1_L5: Membrane Transport Systems Flashcards
Molecules moved out of the cell by fusing with the plasma membrane is known as
Exocytosis
What is another term for a type of endocytosis called
“cell drinking”?
Pinocytosis
What is a passive, spontaneous process that moves molecules down a gradient across the plasma membrane?
Diffusion
Facilitated diffusion uses ___ to help move molecules across the cell membranes
Transport proteins
Osmosis is the movement of ___ across a semipermeable membrane through the lipid bilayer and channels
Solvent
Multipass transmembrane proteins that can change shape to move material from one side of the membrane to the other
Carrier proteins
What are embedded transmembranely and have a
water-filled pore with gates for materials to cross?
Channel proteins
TRUE OR FALSE: A cell in an isotonic solution will have water moving
into the cell.
False
TRUE OR FALSE: Osmosis is energy-requiring
False
TRUE OR FALSE: The end goal of diffusion and osmosis is homeostasis
False
End goal is equilibrium
TRUE OR FALSE: The higher the temperature, the slower the osmotic
rate
False
What kind of gating requires cellular deformation
before transport could occur?
Mechanical gating
Arrange the following into the correct order of biological organization
Choices: tissues, organ systems, organs, cells
Cells, tissues, organs, organ systems
From easiest to difficult, which of the following can
pass through the plasma membrane?
Choices: water, CO2, amino acids
CO2, water, amino acids
TRUE OR FALSE: Diffusion is non-energy requiring
True
What differs active transport from passive transport?
In active transport, materials move against the concentration gradient
Na+ K+ ATPase is an example of what type of transport?
Active transport
Gradient in diffusion moves from?
Higher concentration to lower concentration
TRUE OR FALSE: In diffusion, there is a tendency to equalize number of particles where equal particles must be observed in both concentrations in 2 chambers.
True
What are the 2 most influential factors that maintain the resting membrane potential?
- Potassium leak channels
- Sodium potassium pump (Na K ATPase)
Resting membrane potential of nerve cells
-70 millivolts
What is another term for a type of endocytosis called
“cell eating”?
Phagocytosis
The movement of large molecules into or out of the cell by vesicle formation and fusion.
Macromolecular Exchange
Determine the corresponding descriptions of gating mechanisms
- open or close to changes in electrical potential & accounts for the RMP of cells
- open or close due to cellular deformation
- open or close due to binding of a chemical
- Example of this are sensory receptors
- Example of this are the ACh nicotinic receptors
A. Voltage-gated Gating
B. Ligand Gating
C. Mechanical Gating
- A
- C
- B
- C
- B
Enumerate the 3 factors affecting active transport
- Specificity
- Saturability
- Inhibition
Enumerate the 3 factors affecting carrier-mediated diffusion
- Specificity
- Number of carriers
- Saturability
Enumerate the 2 factors affecting channel-mediated diffusion
- Selectivity
- Gate status
The ___ uses energy derived from gradient created by primary active transport. It couples the kinetic energy of one molecule moving down its concentration gradient to the movement of another against its concentration
gradient.
Secondary Active Transport
The sodium potassium pump is a type of primary active transport that pumps what ions into and out of the plasma membrane?
Pumps out: 3 Na+
Pumps in: 2 K+
Term for when a channel/carrier transfers ions in opposite directions, one going in and one going out. An example of this is the sodium-potassium pump.
Antiport / Countertransport
Term for when a channel or carrier transfers ions from one side to the other simultaneously. An example of this is the sodium-glucose carrier.
Symports / Cotransports
TRUE OR FALSE: The calcium pump is a type of primary active transport where ATP is used to move the calcium ions out of the cell.
True
The gradient in active transport is unnatural. The gradient is from ___
Low concentration to high concentration
TRUE OR FALSE: Potassium channels have no gates and are always open for potassium ions to freely enter.
True
TRUE OR FALSE: In osmosis, movement is from low ion concentration to higher ion concentration
True
Lower ion: plenty of water
Higher ion: plenty of solutes
TRUE OR FALSE: In osmosis, movement is from lower osmotic pressure to greater osmotic pressure
True
The pressure required to stop the process of osmosis
Osmotic pressure
In a container with ___ ion concentration, there is a greater force required to stop osmosis because water has a tendency to go to this container.
higher
TRUE OR FALSE: The higher the partition coefficient, the more soluble the substance is in lipids and the higher is its diffusion
rate.
True
Measures a substance solubility in lipids. The coefficient of a
substance to be divided. This is dependent on absolute temperature, radius, and viscosity.
Partition Coefficient
Determine whether the following will increase or decrease diffusion rate
- low partition coefficient
- more viscous
- higher radius (larger molecule)
- higher temperature
- greater area of diffusion
A. Higher diffusion rate
B. Lower diffusion rate
- B
- B
- B
- A
- A
Term for the temperature in normal physiologic range
Absolute temperature
TRUE OR FALSE: The radius of particles have an inverse relationship with net flow
True
TRUE OR FALSE: Net flow / diffusion rate is directly
proportional to P (standard coefficient of plasma membrane), area of diffusion, and difference in concentration.
True
Most permeable type of matter that easily passes through the plasma membrane
Gas
Arrange the following from most permeable to least permeable through the bilayer
Choices: water, small uncharged particles, charged large polar molecules, large uncharged polar molecules, gases, charged particles
- Gases
- Small uncharged particles
- Water
- Large uncharged polar molecules
- Charged particles
- Charged large polar molecules
