4. Transmembrane Transport Part 3

Question 1

What is active transport?

Answer 1

movement of molecules through the plasma membrane against a gradient requiring an input of energy

Question 2

What is primary active transport?

Answer 2

transport of a molecule that is coupled to ATP hydrolysis

Question 3

What is secondary active transport?

Answer 3

ATP is first used to create a gradient, then the potential energy in that gradient is used to drive the transport of a molecule across the membrane

Question 4

What are the three important functions of the Na/K ATPase pump?

Answer 4

1. maintain osmotic balance between cell interior and exterior
2. establish a resting membrane potential
3. provide the sodium concentration gradient used to drive secondary active transport

Question 5

What is exocytosis?

Answer 5

process to transport material outside of the cell in which a vesicle in the cytoplasm fuses with the plasma membrane and the contents are released into the extracellular space

Question 6

What is endocytosis?

Answer 6

materials are taken into the cell by an invagination of a piece of the cell membrane to form a vesicle

Question 7

What are the three types of endocytosis?

Answer 7

phagocytosis
pinocytosis
receptor-mediated endocytosis

Question 8

What is phagocytosis?

Answer 8

cell eating; nonspecific uptake of large particulate matter into a phagocytotic vesicle which will merge with a lysosome

Question 9

What is pinocytosis?

Answer 9

cell drinking; nonspecific uptake of small molecules and extracellular fluid via invagination

Question 10

What is receptor-mediated endocytosis?

Answer 10

specific uptake marked by pits coated with the molecule clathrin (inside of the cell) and with receptors that bind specific molecules (outside the cell)