Lesson 3: Passive Transport

Question 1

Differnet levels of membrane permeability

Answer 1

-Imprrmeable/ nothing can pass
-Freely permeable/ everything can pass
-Selectivley permeable/ some substances can pass

Question 2

Why is transport needed

Answer 2

-to maintain pH and ionic content in cells for enzyme activity
-to obtain food supplies for energy
-to excrete toxic substances
-to secrete useful substances

Question 3

Passive transport

Answer 3

-Simple diffusion
-Facilitated diffusion
-Osmosis

Question 4

Simple Diffusion

Answer 4

-net movement of particles down a conc gradient from region of high to low conc
-no ATP used

Question 5

Which molecules are moved by simple diffusion

Answer 5

-small non polar molecules like oxygen and carbon dioxide rapidly
-small polar molecules like water but slower
-charged particle can not

Question 6

Facilitated diffusion

Answer 6

-requires the presence of a specialised integral membrane protein
-relies on kinetic energy of diffusing molecules
-occurs along a conc gradient
-occurs at specific points where there are protein molecules
-proteins form water filled channels across the membrane and allow charged ions and large molecules such as glucose and amino acids to pass through

Question 7

Osmosis

Answer 7

movement of water molecules from a region of high concentration to a region of lower conc