Factors that Affect Membranes

Question 1

What are the factors that affect membranes?

Answer 1

Temperature and solvents

Question 2

What happens to the phospholipids below 0C?

Answer 2

They are packed closely together and the membrane is rigid. Channel and carrier proteins can denature which increases the permeability of the membrane. Ice crystals can form and pierce the membrane making it more permeable

Question 3

What happens to the phospholipids between 0C and 45C?

Answer 3

Phospholipids can move freely and the membrane is partially permeable. As the temperature increases, the kinetic energy increases and makes the membrane more permeable

Question 4

What happens to the phospholipids above 45C?

Answer 4

Phospholipids start to melt and the membrane becomes more permeable. Water inside the cell expands putting pressure on the membrane. Channel proteins and carrier proteins denature which increases the permeability of the membrane

Question 5

What happens when Ethanol molecules are inside the membrane?

Answer 5

Form hydrogen bonds with a phospholipid molecule near the ester bonds. Pushes phospholipids out of their orderly placement and increases their movement. Disrupts the membrane structure increasing its permeability. Can also denature proteins by disrupting bonds

Question 6

How can you investigate membrane permeability?

Answer 6

Doing experiments with beetroots. At high temperatures, the membrane fluidity increases and causes the pigment to leak out of the cell. Using a colorimeter, you can measure the amount of pigment

Question 7

What is a colorimeter?

Answer 7

A machine that passes light of a specific wavelength through a lipid and measures how much of that light is absorbed