Osmosis, Diffusion, Active TransportMOVEMENT IN A CELL

Objectives Describe how the transport of materials into and out of a cell helps maintain homeostasis◦ Osmosis, Diffusion, Active Transport

Water

https://www.youtube.com/watch?v=yU_fOSk1pDo&feature=player_embedded

animation http://www.sumanasinc.com/webcontent/animations/content/propertiesofwater/water.html

Water is a solvent It dissolves salts like Sodium chloride, gases like Carbon dioxide, and elements like Oxygen, Calcium, Potassium to transport through our blood stream to and from cells.

Diffusion Movement of any particles from where there are a lot to where there are few.

Osmosis The movement of water across a membrane from an area of high concentration of water to an area of low concentration of water.

◦ From where there’s a lot of water to an area of little water.◦ No energy required for water to move

Osmosis

Salty solutions Hypertonic- where more salt is dissolved compared with water

Isotonic- where equal parts of salt and water are dissolved

Hypotonic- where less salt is dissolved compared with water

Isotonic

Hypertonic

Hypotonic

Pickles are made with Hypertonic salt solution

Blood and salt solutions

Blood cells in salt solutions

What is the effect on eyes in different salt solutions?

Fresh water

Isotonic water

Salty water

Plant that keeps salt out Panicum turgidum

Cows eat it.

Comes from Sahara, Pakistan.

Kidney filter & osmosis

Water moves out at bottom

There is higher amount of water in tube, so water flows out of tube.

Upper part is impermeable to water.

Dialysis of blood

Facilitated Diffusion- no energy required

Active Transport Moving particles from a low concentration to a high concentration.

◦ Moving Calcium from outside a cell to an area inside the cell where there are many calcium atoms requires energy from ATP to force them in.

Protein channel pump

Endocytosis Taking in material into a cell (cell eating)

Exocytosis Transporting material out of the cell. (cell eliminating waste)

Nerve impulses

Sight, Touch, Smell Trigger electrical nerve impulses

Nerve impulses http://www.youtube.com/watch?v=CvktREcRMAo

http://www.youtube.com/watch?v=Iiiz5CpFCQo

Vision

Smell

Pain receptor

Muscle contraction

Muscle contract & relax Contraction: Calcium released by Endoplasmic reticulum connects actin to myosin.

Relaxation: ATP releases the Actin from the Myosin.

Cramps come about from lack of ATP (our energy source).

http://www.youtube.com/watch?v=WVuW560nRII

Brain transmissions There are over 60 neurotransmitter chemicals in our brain.

Happy gas, Nitrogen monoxide (NO), exits the membrane by diffusion and penetrates the neighboring receiving neuron by diffusion.

http://thebrain.mcgill.ca/flash/a/a_01/a_01_m/a_01_m_ana/a_01_m_ana.html

http://www.youtube.com/watch?v=90cj4NX87Yk&list=PLCA3D41F8055EB9E6

Glutamate (also known as Monosodium glutamate)

Brain’s neurotransmitter, memory, learning, regulating cells

Works on brain cells

GABA- (gamma aminobutyric acid) inhibits transmissions

ALS If glutamate stays on the neuron too long then the nerve misfires; evidenced in Lou Gherig’s disease (ALS), can have epilepsy or stroke.

Calcium floods the cell. Calcium normally causes a firing of the cell, but too much Calcium causes the cell to produce an enzyme that destroys the cell.

http://www.youtube.com/watch?v=p7lDaXacuM4&list=PLCA3D41F8055EB9E6

See page 189 of textbook

What Caffeine does to a brain

http://www.youtube.com/watch?v=JP7EQ6e5d1c&list=PLCA3D41F8055EB9E6

Lack of Oxygen in the brain

Too little oxygen causes a release of glutamate, which causes a release of an enzyme that destroys the Calcium protein pump. Too much Calcium produces other enzymes that cause cell death.

Alzheimers Brains NIH video

Protein fibrils are built up between neurons which stop the transmission of brain signals.

http://www.youtube.com/watch?v=NjgBnx1jVIU