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TB - p 90- 91 WB - p 150-151 . Active Transport. Learning intentions: To define active transport To identify types of active transport. Active Transport. Why is it ‘Active’? Energy (ATP) required. ATP is short for Adenosine tri phosphate.
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TB - p 90- 91 WB - p 150-151 Active Transport Learning intentions: To define active transport To identify types of active transport
Active Transport Why is it ‘Active’? • Energy (ATP) required ATP is short for Adenosine tri phosphate • ATP is considered by biologists to be the energy currency of life. • It is the high-energy molecule that stores the energy we need to do just about everything we do. • It is present in the cytoplasm of every cell, and essentially all the physiological mechanisms that require energy to work obtain it directly from the stored ATP. • As food in the cell is used up, the released energy is used to re-form the ATP molecule so that the cell always maintains a supply of this essential molecule
Active transport is • The movement of substances from an area of low concentration to an area of high concentration. IeAgainst the concentration gradient http://www.youtube.com/watch?v=STzOiRqzzL4&NR=1
Three types of Active Transport • Endocytosis • Exocytosis • Ion Pumps Look these terms up in your TB and write down their definitions
Cytosis: movement of large molecules through the cell membrane; requires ATP Endocytosis • Movement into the cell (enter) • Phagocytosis – “cell eating” A food vacuole is formed • Pinocytosis – “cell drinking” A Fluid vesicle is formed • E.g. An Amoeba drinking • Animation of endocytosis
Cytosis: movement of large molecules through the cell membrane; requires ATP Exocytosis • Movement out of the cell (exit) • Vesicles bud off from golgi apparatus or ER, vacuole fuses with cell membrane and expels contents • Secretions e.g. digestive enzymes released, glands • Animation of exocytosis Vacuole
Exocytosis • Or • Endocytosis?
TB - p 90- 91 WB - p 150-151 Active Transport (2) Learning intentions: To define ion pump transport To identify types of ion pumps
Ion: a charged particle Ion Pumps (WB150) • Proteins in the cell membrane can actively accumulate specific ions on one side of the membrane to control the amount • Animation of an ion pump Example 1 –Proton Pump A protein is pumping Hydrogen Ions (protons). It is a proton pump.
Active transport model animation Example 2 – Sodium Potassium Pump
When water is pumped uphill, the energy it creates as it moves freely downhill can be used. The same occurs in cells – Co transport Example 3 - Cotransport A molecules is first pumped against its concentration gradient It then diffuses back The energy created by its diffusion is used to pump another molecule against its concentration gradient 1. 2 3.
