The Cell Membrane and Transport Across the Cell

The Cell Membrane and Transport Across the Cell Membrane

Prokaryotes Eukaryotes Cell membrane Ribosomes Cell wall Animal Cells Lysosomes Plant Cells Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton

Cell Membrane protects and supports prokaryotic and eukaryotic cells and organelles

The cell membrane is a fluid, semi-permeable bilayer that separates the cell's contents from the environment. Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Michondrion

Cell Membrane • Fluid at physiological temperatures and allows cells to change shape due to physical constraints or changing cellular volumes. • Regulates movement of molecules from one side to the other

Phosholipids – form the phospholipid bilayer of the cell membrane Phospholipids - form the phospholipid membranes that surround the cell and intracellular organelles such as the mitochondria. The phospholipid membrane allows free diffusion of some small molecules such as oxygen, carbon dioxide, and small hydrocarbons, but not charged ions, polar molecules or other larger molecules such as glucose, salt. Semi-permeable – allows some things to pass through and not other things

http: //ekgenius. net/Physio/Cell/membrane. html

Max-Planck-Institut für biophysikalische Chemie

Figure 7 -15 The Structure of the Cell Membrane Fluid Mosaic Model Outside of cell Proteins Carbohydrate chains Cell membrane Inside of cell (cytoplasm) Protein channel Lipid bilayer

Diffusion causes many substances to move across a cell membrane but does not require energy.

The movement of water across a semi permeable membrane. Osmosis is the movement of water (red dots) through a semipermeable membrane to a higher concentration of solutes (blue dots). Osmosis does not require energy. What is Osmosis?

Osmosis – water moves from a higher concentration to a lower concentration until equilibrium is reached Higher Concentration of Water molecules Cell membrane Lower Concentration of Water Sugar molecules

Facilitated Diffusion- Diffusion of larger molecules (glucose, starch, salts) using protein channels in the cell membrane, does not require energy Glucose molecules High Concentration Cell Membrane Low Concentration Protein channel

Passive Transport • When material move from areas of high concentration to low concentration they don’t requires energy. – Examples • Diffusion • Facilitate Diffusion • Osmosis Particles Water

Active Transport • When material move from areas of low concentration to high concentration they requires energy. – Examples • Endocytosis • Exocytosis

Exocytosis

Endocytosis

Types of Endocytosis • Phagocytosis • Pinocytosis

Pinocytosis

Pinocytosis

Levels of Organization

Levels of Organization Muscle cell Smooth muscle tissue Stomach Digestive system

Interactive Review http: //www. northland. cc. mn. us/biology/BIOLOGY 1111/animations/passive 1. swf

http: //www. phschool. com/atschool/phbio/active_art/diffusion/index. html http: //www. phschool. com/atschool/phbio/active_art/active_transport/index. html