Topic 2 - CELL PHYSIOLOGY I (Active Processes)

Question 1

Active Processes

Answer 1

• require energy (ATP)

Question 2

what is the difference between active processes and passive transport?

Answer 2

active processes require energy (ATP), passive transport does not.

Question 3

what are the 2 types of active processes?

Answer 3

1. active transport
2. vesicular transport

Question 4

active transport

list 2 characteristics

Answer 4

1. substances move against concentration gradient (low to high)
2. always protein carrier-mediated

Question 5

what are the 2 types of active transport?

Answer 5

1. Primary (1°) active transport
2. Secondary (2°) active transport

Question 6

Primary active transport

Answer 6

molecular pumps - ATP breakdown is directly part of transport process

example:

Na⁺/K⁺ - ATPase - 3 Na⁺ out of cell and 2 K⁺ in per ATP

Question 7

Secondary active transport

Answer 7

cotransport (use of ATP is indirect)

example:

glucose entry at small intestine (2 steps):

step 1: Na⁺ gradient established by Na⁺/K⁺ - ATPase (ATP-use step)

step 2: glucose and Na⁺ both bind to carrier and are cotransported into the cell

⇒ Na⁺ moving down its concentration gradient drives in glucose against glucose concentration gradient (transport step)

therefore, glucose transport is active

Question 8

Vesicular Transport

list 1 characteristic

Answer 8

substance is surrounded by a membrane wihtin a cell (a vesicle)

Question 9

vesicular transport

name the 2 types

Answer 9

1. endocytosis
2. exocytosis

Question 10

vesicular transport: endocytosis

define and name the 2 types

Answer 10

movement into cell

1. phagocytosis
2. pinocytosis

Question 11

vesicular transport: endocytosis: phagocytosis

Answer 11

• large items into cell (e.g. bacteria)
• = “cell eating”

Question 12

vesicular transport: endocytosis: pinocytosis

Answer 12

• fluids (including dissolved substances)
• = “cell drinking”

Question 13

vesicular transport: exocytosis

define and list 2 characteristics

Answer 13

movement out of cell

• vesicles containing hormone, enzymes, neurotransmitter, etc.
• fuse with cell membrane releasing contents into ECF (triggered by a rise in cytosolic Ca⁺⁺)

Question 14

what is the difference between endocytosis and exocytosis?

Answer 14

endocytosis = movement into a cell

exocytosis = movement out of cell

Question 15

what is the difference between phagocytosis and pinocytosis?

Answer 15

phagocytosis = cell eating

pinocytosis = cell drinking