18597103
Pregunta 1
Pregunta
The Na+/K+ pump is:
Respuesta
-
a) cytosolic enzyme;
-
b) membrane protein with enzyme activity;
-
c) membrane lipid.
Pregunta 2
Pregunta
The Na+/K+ pump is found:
Respuesta
-
a) in all types of cells;
-
b) in the excitable cells only;
-
c) in the human excitable cells.
Pregunta 3
Pregunta
The Na+/K+ pump is a type of:
Respuesta
-
a) passive ion transporter;
-
b) facilitated ion channel;
-
c) active ion transporter.
Pregunta 4
Pregunta
Does the Na+/K+ pump require an energy source?
Respuesta
-
a) yes, it hydrolyses adenosine triphosphate;
-
b) no, ions are driven by concentration gradients;
-
c) yes, it uses redox reactions in the annular lipid molecules.
Pregunta 5
Pregunta
What are the operation modes of the Na+/K+ pump?
Respuesta
-
a) electrogenic and non-electrogenic;
-
b) transmembrane and intracellular;
-
c) passive and active.
Pregunta 6
Pregunta
Describe the directions of ion transport through the Na+/K+ pump:
Respuesta
-
a) moves Na+ and K+ ions out of the cell;
-
b) moves Na+ out, and K+ in;
-
c) moves Na+ in, and K+ out.
Pregunta 7
Pregunta
. The Na+/K+ pump is found in:
Respuesta
-
a) cellular membranes;
-
b) cellular membrane and the membrane of the endoplasm reticulum;
-
c) nuclear and cellular membranes.
Pregunta 8
Pregunta
Which of the following transport processes is considered an active transport?
Respuesta
-
a) the transfer of substance (molecules, ions) from area with high concentration into area of lower concentration;
-
b) the transfer of substance (molecules, ions) irregardless of the direction of the concentration gradient;
-
c) the transfer of substance (molecules, ions) from area with low concentration into area of higher concentration;
Pregunta 9
Pregunta
According the type of energy supply, the active membrane transport is divided into:
Respuesta
-
a) primary and secondary;
-
b) simport and antiport;
-
c) active and passive.
Pregunta 10
Pregunta
Which of the following statements does not hold for primary active transport?
Respuesta
-
transmembrane transport of inorganic ions;
-
transmembrane transport of organic molecules;
-
uses energy from ATP.
Pregunta 11
Pregunta
In the electrogenic regime the sodium – potassiumpump:
Respuesta
-
a) moves one negative charge out of the cell;
-
b) moves one positive charge out of the cell;
-
c) moves three positive charges in, for two positive charges out.
Pregunta 12
Pregunta
Which of the following statements refer to the primary active transmembrane transport?
Respuesta
-
a) transport of organic molecules;
-
b) uses the energy of the concentration gradient of Na+;
-
c) involves the active transport of: Na+, K+, Ca2+, H+, Mg2+, Cl-, and bicarbonate ions.
Pregunta 13
Pregunta
The secondary active transport is carried through:
Respuesta
-
a) membrane protein carriers;
-
b) transmembrane ion channels;
-
c) spontaneously formed (and vanishing) membrane pores.
Pregunta 14
Pregunta
The Na+/I- symporter, which transports iodine into the thyroid gland, cannot distinguish between non-radioactive (I-127) and radioactive (I-131) iodine. How could this be explained?
Respuesta
-
a) radioactive and non-radioactive iodine have the same physical properties;
-
b) radioactive and non-radioactive iodine have the same number of neutrons;
-
c) radioactive and non-radioactive iodine have the same chemical properties.
Pregunta 15
Pregunta
What type of membrane transport delivers iodide into the thyroid gland?
a) passive transport;
Respuesta
-
a) passive transport;
-
b) primary active transport;
-
c) secondary active transport.
Pregunta 16
Pregunta
What is the direct driving force for the transmembrane transport of iodide?
Respuesta
-
a) energy from the hydrolysis of ATP;
-
b) the electrochemical gradient of Na+ ions;
-
c) the concentration gradient of Na+ ions.
Pregunta 17
Pregunta
Antiport is defined as:
Respuesta
-
a) coupled membrane transport, where substances move in the same direction;
-
b) coupled membrane transport, where substances move in opposite directions;
-
c) ion channel that allows ions to move only in one direction.
Pregunta 18
Pregunta
The operational mode of the thyroid Na+/I- symporter is as follows:
Respuesta
-
a) 2 Na+ ions move in, for each I- ion moving in;
-
b) 2 Na+ ions move out, for each I- ion moving in;
-
c) 3 Na+ ions move in, for 2 I- ions moving out.
Pregunta 19
Pregunta
An example for secondary active transport is:
Respuesta
-
a) the Ca2+ pump;
-
b) the Na+/I- symporter;
-
c) the K+ leak channel.
Pregunta 20
Pregunta
The electrogenic mode of operation of the Na+/K+ pump is as follows:
Respuesta
-
a) 2 Na+ ions move out, for 3 K+ ions moving in;
-
b) 3 Na+ ions move out, for 2 K+ ions moving in;
-
c) 3 Na+ ions move in, for 2 K+ moving out;
Pregunta 21
Pregunta
Transmembrane transport of substances against their electrochemical gradient, that does not use direct coupling of ATP is called:
Respuesta
-
a) passive transport;
-
b) primary active transport;
-
c) secondary active transport.
Pregunta 22
Pregunta
When substances are transported across the membrane through specialised protein molecules, the process is described as:
Respuesta
-
a) simple diffusion;
-
b) uniport or cotransport;
-
c) protein transport.
Pregunta 23
Pregunta
When substances use protein carrier molecules to cross the membrane, the process is described as:
Respuesta
-
a) simple diffusion;
-
b) protein-lipid transport;
-
c) facilitated diffusion.
Pregunta 24
Pregunta
What type of membrane transport involves the accumulation of iodine in the follicular cells of the thyroid gland?
Respuesta
-
b) secondary-active;
-
c) facilitated passive.
-
a) primary-active;
Pregunta 25
Pregunta
The primary active membrane transport is carried by:
Respuesta
-
a) aquaporins;
-
b) ion channels;
-
c) ion pumps.
Pregunta 26
Pregunta
The bi-directional secondary active transport is called:
Respuesta
-
a) simport;
-
b) antiport;
-
c) uniport.
¿Quieres crear tus propios Tests gratis con GoConqr? Más información.