Passive vs Active Transport

Question 1

Define passive transport

Answer 1

Movement of material along a concentration gradient, from a high concentration to a low concentration, no energy is required.

Question 2

Name three main kinds of passive transport

Answer 2

Simple diffusion ( movement of small or lipophilic molecules - O2, Co2), Osmosis (movement of water molecules) and Facilitated diffusion (movement of large or charged molecules through either channel or carrier proteins).

Question 3

Describe the difference between carrier and channel proteins

Answer 3

Channel proteins carry charged and polar molecules (K+, Na+), while Carrier proteins carry uncharged, non-polar molecules (glucose, sucrose)

Question 4

Define active transport

Answer 4

Involves movement of materials against a concentration gradient (low to high), it requires ATP hydrolysis

Question 5

What are the two main kinds of active transport?

Answer 5

Primary (direct) - uses direct use of metabolic energy such as ATP hydrolysis to mediate transport with transport proteins (pumps)
Endocytosis and Exocytosis - using cell membranes to enclose and release vesicles. Also secondary (indirect) active transport - coupling molecule with another moving along an electrochemical gradient.