Exam 1 Flashcards
- Maintenance of static or constant conditions of the “milieu intérieur” is referred to as:
A) Homeostasis
B) Hemostasis
C) Differentiation
D) Environmental control
A) Homeostasis
- Which of the following is NOT usually associated with positive feedback?
A) Generation of Nerve signals B) Amplification C) Reinforcing feedback D) Vicious cycles E) Homeostatic “control systems”
E) Homeostatic “control systems”
- A pure phospholipid belayer is most permeable to which of the following?
A) Water B) Sodium C) Calcium D) Chloride E) Oxygen
E) Oxygen
- Which of the following characteristics of a biological membrane is most influenced by its cholesterol content?
A) ion permeability B) thickness C) fluidity D) glycosylation E) hydrophobicity
C) Fluidity
Match each process to one of the following: A. Simple Diffusion B. Facilitated Diffusion C. Primary active transport D. Co-transport E. Counter transport
- Glucose uptake into skeletal muscle (——).
- Glucose uptake in skeletal muscle (B. Facilitated Diffusion)
Match each process to one of the following: A. Simple Diffusion B. Facilitated Diffusion C. Primary active transport D. Co-transport E. Counter transport
- Na+ dependent transport of Ca2+ from the cytosol to the extra cellular fluid (——).
- Na+ dependent transport of Ca2+ from the cytosol to the extra cellular fluid (E. Counter-transport)
Match each process to one of the following: A. Simple Diffusion B. Facilitated Diffusion C. Primary active transport D. Co-transport E. Counter transport
- Transport of glucose from the intestinal lumen to an intestinal epithelial cell (——).
- Transport of glucose from the intestinal lumen to an intestinal epithelial cell (D. Co-transport).
Match each process to one of the following: A. Simple Diffusion B. Facilitated Diffusion C. Primary active transport D. Co-transport E. Counter transport
- Movement of Na+ ions into a nerve cell during the upstroke of an action potential (——).
- Movement of Na+ ions into a nerve cell during the upstroke of an action potential (A. Simple diffusion)
- If the intracellular concentration of a electrically neutral, membrane permeant substance doubles from 10-20 millimolar, the rate of diffusion of that substance across the plasma membrane will increase by how much?
A) 2 B) 3 C) 4 D) 5 E) 6
B) 3
J = > [concentration gradient]
- Which of the following first principle relationships is NOT used in the derivation of the Electrodiffusion Model:
A) Fick’s Law
B) Maxwell’s Equations
C) Electrophoresis
D) Ohm’s Law
B) Maxwell’s Equation
11) The diagrams above depict rigid containers composed of two aqueous chambers, A and B, each containing an Na+ solution and separated by a Na+-permeable membrane. The panel on the left represents the distribution of Na+ ions at rest in the absence of any electrical potential. In this scenario, the concentration of Na+ ions in chamber A equals the concentration of Na+ ions in chamber B. The panel on the right illustrates the effect of a +60-millivolt potential applied across the membrane (chamber B relative to chamber A). Assuming a temperature of 37 degrees Celsius, which of the following expressions best describes the resulting distribution of x ions between the two chambers?
(A) [Na]A=2[Na]B (B) [Na]A=10[Na]B (C) [Na]A=60[Na]B (D) [Na]B=10[Na]A (E) [Na]B=60[Na]A
D) [Na]B = 10[Na]A
When a positive electrical charge of 60 millivolts is applied to chamber B, the positively charged Na+ ions are repelled from chamber B into chamber A until the diffusional force from the concentration gradient is sufficient to counter the electromotive force. Using the Nernst equation, a 60-millivolt electromotive force would be offset by a 10-fold Na+ concentration gradient. Therefore, at the new steady state, the [Na]A would be 10 times the [Na]B.
12) The electrical circuit element used to model ion channels is:
A) Battery
B) Resistor
C) Capacitor
D) Inductor
B) Resistor
13) The membrane capacitance is NOT a factor of:
A) The concentration of integral proteins in the membrane
B) The membrane dielectric constant
C) The membrane thickness
D) The membrane area
A) The concentration of integral proteins in the membrane
14) Cable theory is used for passive membranes to model electrical current flow:
A) along membranes
B) across synapses
C) during action potentials
D) from recording electrodes
A) along membranes
15) List the 4 elements of a control system and draw
- Sensor: checks it
- Comparator: compares to set value
- Controller: sends signal to effector
- Effector: executes the action
O->4.———–>1.—->
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I |
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