Question

What does selective what does selective permeability mean? *

-No energy is needed
-All materials move across the membrane
-Some materials pass through, but others cannot
-Materials move from high concentration to low concentration

Answer 1

Selective permeability allows certain materials to pass through the cell membrane while blocking others, essential for cell survival. Passive transport, which includes diffusion, osmosis, and facilitated diffusion, moves substances along the concentration gradient without the use of energy.

Step-by-step explanation:

Selective Permeability of Cell Membranes

Selective permeability is a property of cellular membranes that allows some substances to pass through, while preventing others. This characteristic is vital for maintaining the health of the cell, allowing the entry of essential substances and the removal of waste products. The cell membrane is composed of a lipid bilayer with embedded proteins, creating a barrier that regulates the movement of materials.

Passive transport is a form of membrane transport that does not require energy. In passive transport, substances move across the membrane from an area of higher concentration to an area of lower concentration, following the concentration gradient. There are three main kinds of passive transport: diffusion, osmosis, and facilitated diffusion. Diffusion involves the movement of small molecules or ions, while osmosis specifically refers to the diffusion of water across a semipermeable membrane. Facilitated diffusion requires the presence of special membrane proteins that assist in the movement of substances across the membrane.