Ch 1.6 selective permeability

Question 1

What is semipermeable part of the membrane?

Answer 1

Filters particles by size, solubility, charge ( osmosis/ diffusion )

Question 2

Selectively permeable?

Answer 2

Choses molecules based on a criteria ( active/ facilitated transport)

Question 3

Is the membrane semipermeable or selectively permeable?

Answer 3

Selectively permeable ( not permeable to polar or large molecules)

Question 4

Rank things from least to most permeable

Answer 4

• large macromolecules (Protein DNA)
• ions ( Na +)
• large molecules (glucose )
• small molecules (water)

Question 5

What is diffusion?

What are the two types in cells?

Answer 5

• from high concentration to low concentration
• random movement molecules
• simple diffusion ( through bilayer)
• facilitated diffusion ( use protein channels)

Question 6

What is Osmosis

How do plants and animals regulate it?

Answer 6

Movement water across a selectively permeable membrane to a higher solute concentration

• animals: control by osmolarity ( solute solution (
• plants, bacteria, fungi : use cell wall pressure

Question 7

What is a concentration gradient

Answer 7

Uneven distribution molecules

Question 8

How does water get into the cell?

Answer 8

• osmosis

- aquaporins ( passive diffusion)

Question 9

What’s the difference between passive and active transport?

Answer 9

• Active goes against the gradient, needs energy (pumps)

- passive goes with, no energy

Question 10

What is an electrochemical gradient used for?

Answer 10

An energy source for secondary active transport

Question 11

What is secondary transport?

Answer 11

Uses an electrochemical gradient to transport one against and one with the gradient.