Why is the cell membrane so important Cell

Why is the cell membrane so important?

Cell Membrane Basics 1. Also known as the plasma membrane 2. Semi-permeable-only some material can get in or out 3. Has a phospholipid bilayer inside cell outside cell

Semi-Permeable Membrane • Controls what gets in or out • Needs to allow some materials — but not all — to pass through the membrane inside cell waste outside cell lipid salt sugar aa H 2 O

Semi-Permeable Membrane What gets in easily? 1. Lipids 2. Water Why? 1. Channels are made out protein; “likes” both water and lipids

Semi-Permeable Membrane Movement • Movement Types: • Passive Transport- No energy required • Active Transport- Energy required (ATP)

Passive (No Energy) Transport • Diffusion – molecules move from a high to low concentration • Osmosis- water moves from a high to low concentration • Wants to create homeostasis! High Low

Osmosis Water balance is important! 1. Hydrated 2. Dehydrated 3. “Drown”

Hypotonic Solution: Higher concentration of fresh water outside of the cell. Cell swells and bursts. Hypotonic Solution: Equal amount of fresh water inside and outside of cell. Hypertonic Solution: Lower concentration of fresh water outside of the cell. Cell shrinks.

Two Types of Diffusion • Simple Diffusion: Osmosis and Diffusion • Facilitated Diffusion: • Uses protein pump due to size of molecules

Active Transport • Molecules move from low to high • Requires energy (ATP) VS

Active Transport • Endocytosis: Engulfs/Brings in molecules • Exocytosis: Allows molecules and waste to exit a cell