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Crossing the Cell membrane

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Presentation on theme: "Crossing the Cell membrane"— Presentation transcript:

1 Crossing the Cell membrane

2 Diffusion

3 FROM A LOT TO NOT A LOT Molecules move _______“where there’s _______”
Animatioin from: Molecules move _______“where there’s _______” ____“where there’s ___________” FROM A LOT TO NOT A LOT

4 DIFFUSION across a space
Happens anytime there is a __________ in concentration in one place compared to another. This is called the_____________ DIFFERENCE Concentration gradient

DOWN Molecules move automatically _______ the concentration gradient _______ an area of _______ concentration ____ an area of ________ concentration EXAMPLES from Higher to Lesser Blue dye in beaker demo, Kool Aid, someone making popcorn, grilling out, strong perfume, bad smell in room

6 DIFFUSION across a space
Diffusion continues until the concentration is _________in space = ___________ ballanced Equilibrium

7 Kidspiration by: Riedell

8 Kinds of ________ Transport
PASSIVE __________________________________ ___________________________________ Ion Channel Facilitated Diffusion Osmosis

9 Molecules need to move across membranes in cells
Image modiified from:

10 Diffusion can happen ________ a _____________ in a cell
across membrane …as long as membrane will let the molecule _________________ pass through

11 DIFFUSION across a membrane
difference Happens anytime there is a __________ in _____________ on one side of the membrane compared to the other concentration Examples of molecules that move by diffusion across membranes in cells: See diffusion animation OXYGEN, WATER, CARBON DIOXIDE, NITROGEN

12 CELL EXAMPLE: DIFFUSION automatically moves oxygen from HIGHER concentration (in lungs) to a LOWER concentration (in blood) CO2 automatically moves from where there is a HIGHER concentration (in blood) to where there is a lower concentration (in lungs)


14 OSMOSIS OSMOSIS DIFFUSION Semi-permeable lower
= SPECIAL KIND OF DIFFUSION IMAGE by RIEDELL OSMOSIS ____________ See osmosis animation DIFFUSION __________ Movement of molecules across a _________________ membrane from ______ concentration to _____ Semi-permeable lower Higher

15 BUT…. What if a cell needs to move _____ or ______ molecules?

16 Facilitated Diffusion _______ proteins help diffusion go faster

17 What if cell needs to move a molecule _________ the CONCENTRATION GRADIENT? _______________
AGAINST (LOWER  HIGHER) Cell example: Want to put MORE glucose into mitochondria when there is already glucose in there Image from:

18 What if cell needs to move molecules really _______
What if cell needs to move molecules really _______? (can’t wait for it to diffuse) FAST Cell example: Movement of Na + & K+ ions required to send nerve signals

19 We need a ____ to ____ molecules across cell membranes that _______ across by ___________
WAY HELP can’t go themselves

PASSIVE No energy required = __________________ Moves _________ concentration gradient from ________________________ _____________________ grab molecule, change shape, and flip to other side (Like a revolving door) Molecules that move this way in cells: _______________________ DOWN HIGHER to LOWER Membrane proteins GLUCOSE

21 Facilitated Diffusion
Animation from:

22 Kidspiration by: Riedell

23 Kinds of ________Transport
ACTIVE ________________________________________ ___________________________________ ____________________________________ Sodium-Potassium Pump Endocytosis Exocytosis

24 See a video clip about Na+-K+ pump -7D

25 Sodium (Na+)- Potassium (K+) Pump
Animation from: See a movie about Na+ - K+ pump

26 Sodium-Potassium pump
ACTIVE ___________ transport (requires energy from ______) Special just for Na+ and K + ions Uses integral ___________________ to move molecules Examples in nerve cells: Na+ is pumped out of cells at same time K + is taken into cells ATP Carrier Proteins

27 See a video clip about Endo/exocytosis -7E

28 ENDOCYTOSIS Takes substances into cell
ACTIVE _____________transport (requires __________ from ______) Uses small membrane sacs called ______________ to carry substances energy ATP VESICLES

29 2 KINDS of ENDOCYTOSIS Takes substances into cell
If taking in: fluid or small molecules =_________________ large particles or whole cells =______________ Examples in cells: one celled organisms eat this way white blood cells get rid of bacteria this way PINOCYTOSIS PHAGOCYTOSIS

30 Pinocytosis Called “Cell Drinking”

31 ENDOCYTOSIS Animation from:

32 PHAGOCYTOSIS Called “Cell Eating” ___________ destroying _______ germs
White blood cell germs ___________ destroying _______

33 EXOCYTOSIS Substances released outside of cell
ACTIVE __________ transport (requires __________) Substances move in____________ Examples in cells: _________ release packaged proteins this way energy VESICLES GOLGI

34 Exocytosis

Video: GOLGI BODIES USE EXOCYTOSIS Animation from: See a Golgi movie

36 Endocytosis & Exocytosis
Videos from: Endocytosis & Exocytosis Watch a video clip about endo/exocytosis Choose Screen/Switch programs to view

37 INSULIN being released by pancreas cells using exocytosis

38 What if there is a difference in concentration but solute molecules can’t move across a membrane?
WATER will move until concentration reaches equilibrium

39 VOCAB _____________ = substance that is dissolved in a solvent to make a solution _____________ = substance in which a solute is dissolved SOLUTE SOLVENT EX: Koolaid powder = solute Water = solvent Koolaid drink = solution

40 Images by Riedell __________________ = mass of a solute in a given volume of solution CONCENTRATION MORE The _______ molecules there are in a given volume the ____________the concentration GREATER

41 See a video clip about OSMOSIS -7B

42 See an animation Osmosis1

Animation from: OSMOSIS See an animation OSMOSIS 4 HYPERTONIC: Concentration outside cell is ____________________ inside cell More water leaves cell than enters so cell ____________ GREATER THAN shrinks

44 Cell in Hypertonic Solution
15% NaCL 85% H2O ENVIRONMENT CELL 5% NaCL 95% H2O What is the direction of water movement?

45 OSMOSIS Swell and possibly burst LESS THAN
Animation from: OSMOSIS See an animation Osmosis3 HYPOTONIC: Concentration outside cell is ________________ inside the cell More water enters than leaves cell so cell will ___________________ LESS THAN Swell and possibly burst

46 Cell in Hypotonic Solution
10% NaCL 90% H2O CELL 20% NaCL 80% H2O What is the direction of water movement?

47 OSMOSIS ISOTONIC: Concentration outside cell __________ EQUALS
concentration inside cell Water entering = water leaving so cell _____________________ EQUALS STAYS THE SAME SIZE

48 Cell in Isotonic Solution
10% NaCL 90% H2O ENVIRONMENT CELL NO NET MOVEMENT 10% NaCL 90% H2O What is the direction of water movement? equilibrium The cell is at _______________.

49 NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
Isotonic Solution Hypotonic Solution Hypertonic Solution NO NET MOVEMENT OF H2O (equal amounts entering & leaving) Cell Swells & may burst Cell shrivels up

50 Animal cells

51 Osmosis in Red Blood Cells
Isotonic Hypertonic Hypotonic

52 Plant cells _____ keeps CELL WALL Plant cells from bursting
Plant cells CELL WALL _____ keeps Plant cells from bursting

53 VACUOLES store WATER OSMOTIC PRESSURE _____________________________ =
OSMOTIC PRESSURE _____________________________ = Pressure exerted by water during osmosis

54 SO WHAT? hypotonic Bath water is ________________ compared to you
Sitting in the bathtub causes your fingers and toes to wrinkle up when water ________ your skin cells by osmosis enters

55 Grocery stores spray water on their veggies to “plump them up”


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