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