Cell Mebrane

Question 1

What s the function of the plasma membrane

Answer 1

Surrounds the cell
Separates from environment
Selectively permeable
Enables communication with surroundings

Question 2

What is the structure of the plasma membrane

Answer 2

Lipid belayer composed:
phospholipids( polar head and non polar tail)
Cholesterol (adds rigidity)
Proteins (for transport)
Carbs (for recognition)

Question 3

Why is plasma membrane described as fluid membrane

Answer 3

It is flexible and composed of various molecules that move fluidly within the bilayer

Question 4

What are the main ways molecules cross the plasma membrane

Answer 4

Passive transport- diffusion and osmosis
Active transport
Bulk transport- endocytosis, exocytosis

Question 5

What is passive transport

Answer 5

Movement of molecules without energy expenditure, following concentration gradient

Question 6

Example of passive transport

Answer 6

Diffusion- movement from high to low conc
Osmosis- diffusion of water across a selectively permeable membrane
Facilitated diffusion- transport vi specific carrier proteins