08 - Bio Lecture 3/5/08 Cell Membranes Chapter 5 4)...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Bio Lecture – 3/5/08 Cell Membranes – Chapter 5 4) Transport of substances across membranes * Cells must control their contents * Lipid bilayer structure of the cell membrane prevents water soluble substances from * Movement of substances across membranes of 2 types: 1) Require no energy (passive) 2) requires energy (ATP) * Types of transport of substances across the cell membrane: 1) Diffusion 2) Osmosis 3) Facilitated transport 4) Active Transport (requires energy) 1) Movement NOT requiring energy All molecules move The hotter they are the faster they move Eventually become evenly distributed Net movement of molecules from an area where they are highly concentrated to areas of low concentration = diffusion Substances that move across cell membrane by diffusion: Water, oxygen, CO2 Example: Drop of dye in a beaker of pure water. Highly concentrated at first, becomes evenly distributed in water after time. Diffusion of dye in water
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

08 - Bio Lecture 3/5/08 Cell Membranes Chapter 5 4)...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online