# Cells and Their Environment How does “stuff” get from the environment into the cell, or from the cell to the environment?

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Cells and Their Environment How does “stuff” get from the environment into the cell, or from the cell to the environment? http://images.google.com/imgr es?imgurl=http://members.trip od.com/mistergecko0/0d5912 e0.jpg&imgrefurl=http://memb ers.tripod.com/mistergecko0/i d49.htm&h=302&w=401&sz= 37&hl=en&start=8&tbnid=_l8e 0mFdRLfGZM:&tbnh=93&tbn w=124&prev=/images%3Fq% 3Dsnake%2Beating%26gbv% 3D2%26svnum%3D10%26hl %3Den%26sa%3DG http://images.google. com/imgres?imgurl= http://dogs.thefuntim esguide.com/images/ blogs/puppy- checking-out-adult- dog- pooping.jpg&imgrefur l=http://dogs.thefunti mesguide.com/2007/ 06/dog_pees_on_car pet.php&h=531&w=8 00&sz=435&hl=en&s tart=19&tbnid=2wa- Uh50zEi0aM:&tbnh= 95&tbnw=143&prev= /images%3Fq%3Dan imal%2Bgoing%2Bto %2Bthe%2Bbathroo m%26start%3D18%2 6gbv%3D2%26ndsp %3D18%26svnum% 3D10%26hl%3Den% 26sa%3DN

Two ways “stuff” gets in and out of a cell. 1. Passive Transport 2. Active Transport What is the “stuff” moving in and out? - ions (K+, Na+), glucose, proteins, many other molecules, solute 8.1 In text

1. Passive Transport - movement across the cell membrane that does NOT require energy from the cell - Material / “stuff” will move down the concentration gradient - Concentration gradient – a difference in concentration of the substance / “stuff” - When the concentration of “stuff” is equal on both sides of the CM, an equilibrium is met, and there is no more net movement ( tennis ball example)

Passive Transport Cont. A. Diffusion - movement of particles from an area of high concentration to an area of low concentration caused by the random motion of the particles (ex. food coloring) Equilibrium has been met Cube has high concentration of sugar, water has low concentration http://images.google.com/imgres?imgurl=http://faculty.southwest.tn.edu/rburkett/GB1-os18.jpg&imgrefurl=http://faculty.southwest.tn.edu/rburkett/GB1- osmosis.htm&h=406&w=542&sz=30&hl=en&start=2&tbnid=qbTcrmH2OmYtiM:&tbnh=99&tbnw=132&prev=/images%3Fq%3Ddiffusion%2Bdiffusion%26gbv%3D2 %26svnum%3D10%26hl%3Den%26sa%3DG

http://icanhascheezburger.files.wordpress.com/2007/10/128344536516093750alrightwhof.jpg

1. Passive Transport Cont. B. Osmosis - the diffusion of water through a selectively permeable membrane. (starch and iodine demo) - water moving so that there will be an equal # of free water molecules or - water moving to where there is the greatest amount/concentration of “stuff”

Results of Osmosis http://images.google.com/imgres?imgurl=http://kentsim mons.uwinnipeg.ca/cm1504/Image130.gif&imgrefurl=ht tp://kentsimmons.uwinnipeg.ca/cm1504/membranefunc tion.htm&h=490&w=800&sz=53&hl=en&start=15&tbnid =pjx3yqtyP25G6M:&tbnh=88&tbnw=143&prev=/image s%3Fq%3Dcells%2Bin%2Bhypertonic%2Band%2Bhyp otonic%2Bsolution%26gbv%3D2%26svnum%3D10%2 6hl%3Den%26sa%3DG Water moves into cell No net move- ment of water Water moves out (sketch on overhead) Turgor pressure in plants, keeps them erect.

1. Passive Transport Cont. C. Fascilitated diffusion - carrier proteins are used to transport specific substances (figure 8.5 in text) Notice: FD is still going with the concentration gradient From same site as diffusion image Where is the highest concentration of particles? Where is the lowest concentration of particles?

2. Active Transport – movement of a substance (“stuff”) across the cell membrane against its concentration gradient - requires energy - that energy is usually ATP - carrier proteins are called pumps http://images.google.com/imgres?imgurl=http://fajerpc.magnet.fsu.edu/Education/2010/Lectures/12_Membr ane_Transport_files/image032.jpg&imgrefurl=http://fajerpc.magnet.fsu.edu/Education/2010/Lectures/12_Me mbrane_Transport.htm&h=251&w=354&sz=12&hl=en&start=11&tbnid=PriqgvjBJMFJOM:&tbnh=86&tbnw= 121&prev=/images%3Fq%3Dactive%2Btransport%26gbv%3D2%26svnum%3D10%26hl%3Den%26safe% 3Dactive

2. Active Transport Cont. Organisms source of E: ATP –Adenosine triphosphate –Quick, usable –ATP  ADP + P + Energy –ADP + P + Energy  ATP (D for di or 2, T for tri or three)

What is ATP? ADENOSINE TRIPHOSPHATE  ADENOSINE DIPHOSPHATE + + Energy P This molecule has LOTS of quick usable ENERGY stored in the bonds between the phosphates!!! We can use this ENERGY to run, walk, think play, sing, etc What happens in tug-of-war when a side lets go? An organic compound, a nucleic acid

2. Active Transport Cont. Vesicles Across the Membrane - endocytosis – endo=inside cytosis=cell - exocytosis Both of these use the CM to form vesicles/ pouches around the material to bring them in or out. http://images.google.com/imgres ?imgurl=http://media- 2.web.britannica.com/eb- media/38/8038-004- A29C9C02.jpg&imgrefurl=http:// www.britannica.com/EBchecked /topic- art/101396/106999/Endocytosis- and-exocytosis-are- fundamental-to-the-process http://images.google.com/imgres ?imgurl=http://media- 2.web.britannica.com/eb- media/38/8038-004- A29C9C02.jpg&imgrefurl=http:// www.britannica.com/EBchecked /topic- art/101396/106999/Endocytosis- and-exocytosis-are- fundamental-to-the-process ntracellular&h=300&w=375&sz= 29&hl=en&start=5&um=1&usg= __qc9ImyY4ZUibuL8833LAdLqJ ueQ=&tbnid=ebe_i8Mc_SX5BM: &altq=lysosome,vacuole,&tbnh= 98&tbnw=122&prev=/images%3 Fq%3Dendocytosis%26um%3D 1%26hl%3Den%26sa%3DN Enlarge image

The End ... Just kidding, one more slide But you don’t have to take notes

4.2 Active Transport Cont. Sodium-Potassium pump - very important membrane pump - carries both Na+ and K+ against their concentration gradients - 3Na+ out of cell & 2K+ into the cell Sodium-Potassium Pump

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