Biophysics Flashcards
Which of the following describes the process of diffusion?
a) Movement of molecules from a region of high concentration to low concentration
b) Movement of molecules from a region of low concentration to high concentration
c) Movement of molecules from a region of equal concentration to another region of equal concentration
d) Movement of molecules from a region of low concentration to another region of low concentration
Movement of molecules from a region of high concentration to low concentration
The resting membrane potential inside the cell is?
-70mV
________ has high concentration outside.
Na+
Diffusion of a Solute is defined by _________ Equation?
Fick’s Equation
Flux is a _________ quantity
a. Scaler
b. Vector
c. Positive
d. Negative
Vector
The net flux of a particle is dependent on the
diffusion coefficient of the medium for the particle, and the difference in concentration of the particle. True or false?
True
Permeability does NOT depend on:
a. Type of ion
b. Thickness of the membrane,
c. Temperature
d. Area
Area
Name Small uncharged Polar Molecules?
H2O
urea
glycerol
C02
O2,
alcohol
Name Large Uncharged Polar Molecules?
Glucose
Sucrose
Which of the following is an example of active transport?
a) Osmosis
b) Diffusion
c) Facilitated diffusion
Osmosis
Which of the following is a factor that affects the rate of osmosis?
a) Size of the molecules
b) Charge of the molecules
c) Temperature
d) All of the above
All of the above
Which of the following statements about diffusion is true?
a) It requires the input of energy
b) It occurs from areas of low concentration to high concentration
c) It occurs from areas of high concentration to low concentration
d) It is a highly selective process
It occurs from areas of high concentration to low concentration
Which of the following is NOT a characteristic of osmosis?
a) It is a passive process
b) It only occurs in living organisms
c) It involves the movement of water
d) It occurs across a semi-permeable membrane
It only occurs in living organisms
Which of the following factors affect the rate of diffusion?
a) Temperature
b) Concentration gradient
c) Membrane permeability
d) All of the above
All of the above
Which of the following is an example of osmosis in living organisms?
a) Movement of water from soil to plant roots
b) Movement of water from blood to cells
c) Movement of water from the bladder to urine
d) Movement of water from the stomach to small intestine
Movement of water from blood to cells
The Nernst equation is used to calculate:
a. The electrical potential across a cell membrane
b. The concentration of ions inside and outside a cell
c. The rate of ion diffusion across a cell membrane
d. The electrical conductivity of a cell membrane
The electrical potential across a cell membrane
The Nernst equation is applicable for which type of ions?
a. Only positively charged ions
b. Only negatively charged ions
c. Both positively and negatively charged ions
d. None of the above
Both positively and negatively charged ions
In the Nernst equation, what does the variable “R” represent?
The gas constant
The Nernst equation can be used to calculate the equilibrium potential for _______ ion?
Potassium (K+)
The equilibrium potential for an ion is dependent on:
a. The concentration gradient of the ion across the cell membrane
b. The electrical gradient of the ion across the cell membrane
c. The temperature of the cell
d. Both a and b
d. Both the concentration gradient of the ion across the cell membrane and the electrical gradient of the ion across the cell membrane
Which ion has a higher equilibrium potential in neurons, potassium or sodium?
Potassium
Which of the following factors can affect the resting membrane potential of a neuron?
a. Changes in the extracellular concentration of ions
b. Changes in the intracellular concentration of ions
c. Changes in the permeability of the cell membrane to ions
d. All of the above
All of the above
If the concentration of potassium inside a neuron is 100 mM and the concentration of potassium outside the neuron is 10 mM, what is the equilibrium potential for potassium (in mV) according to the Nernst equation?
a. -60 mV
b. -70 mV
c. -80 mV
d. -90 mV
-90 mV
If the concentration of sodium inside a neuron is 10 mM and the concentration of sodium outside the neuron is 100 mM, what is the equilibrium potential for sodium (in mV) according to the Nernst equation?
+60 mV