Bio cellular transport
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Transcript of Bio cellular transport
Cellular Transport
An Overview
How does the polarity of water make hydrogen bonding possible?
• Water is a polar molecule– slightly positive end (H) and slightly negative end
(O) because electrons spend more time in orbit around larger O molecule
– H’s of one water molecule are attracted to O’s of another• Form Hydrogen bonds• H-bonds are usually weak, but are unusually strong in
water• Gives water several important properties
Hydrogen Bonding• http://www.classzone.com/cz/bo
oks/bio_09/resources/htmls/animated_biology/unit1/bio_ch02_0041_ab_bonding.html
How are the 3 properties important in cells and organisms?
• 3 important properties:– Cohesion• Water molecules stick together• Surface tension, blood
– Adhesion• Water molecules stick to other things• Capillary action
– High Specific Heat• Water resists changes in temperature• Chemical reactions produce a lot of heat• Maintains homeostasis
What is blood?
• Liquid part is called plasma– About 95% water
• Also includes red blood cells, white blood cells, platelets, sugars, proteins, etc.
Water as a Solvent
• Water is an excellent solvent, but not the “universal solvent” as commonly called
• Water readily dissolves polar substances and ionic compounds– Sugars, proteins, salts
• Water does not dissolve nonpolar substances– Fats, oils
Double Layer of Phospholipids
Other components of the Cell Membrane
• Proteins– Aid in transport of materials in and out of cell– Anchor cell membrane to cytoskeleton
• Carbohydrate chains– Identify cells
• Cholesterol– Strengthen membrane
How is the cell membrane like a window screen?
• Selective Permeability– It allows some molecules
to pass through it but not others
– Some molecules need an opening, like a transport protein
Cellular Transport
• Two types– Passive transport• Particles move from higher concentration to lower
concentration, requires no cellular energy• Diffusion, facilitated diffusion, osmosis
– Active Transport• Particles move from lower concentration to higher
concentration, requires cellular energy• Pumps, endocytosis, exocytosis
Passive Transport
Passive Transport: Osmosis
Tonicity Animation
Active Transport
Active Transport Passive Transport
Active transport in the body
• Sodium-Potassium Pumps– Help your nerve cells to function– Pump sodium ions out of and potassium ions into
cell• Endocytosis– Cell eating and drinking (single-celled organisms)
• Exocytosis– Cell secretions, waste disposal
Endo/Exocytosis
Cellular Transport Review
• http://www.classzone.com/cz/books/bio_09/resources/htmls/animated_biology/unit2/bio_ch03_0093_ab_cellmem.html