Presentation on theme: "Cellular Transport. Introduction to Cell Transport Cell transport= moving materials in and out of a cell All living cells need to be able to: – Take in."— Presentation transcript:
Introduction to Cell Transport Cell transport= moving materials in and out of a cell All living cells need to be able to: – Take in oxygen and nutrients – Get rid of wastes The cell membrane separates the inside of the cell from the outside. – It allows some things to enter and blocks other things
Cell Membrane Structure Phospholipid Bilayer- double layer of phospholipids enclosing the cell 1.Bilayer: Exterior and interior surface: heads Between: tails
Membrane Proteins Membrane proteins can be used to: – transport materials thru the membrane – serve as chemical signals or receptors of chemical signals. Membranes also can contain cholesterol (animal cells) and glycoproteins.
Fluid Mosaic Model Describes the cell membrane as a fluid rather than a solid. – Phospholipids and some proteins are able to move – This is able to change its shape and form. http://www.youtube.com/watch?v=Qqsf_UJcf Bc http://www.youtube.com/watch?v=Qqsf_UJcf Bc
Selective Permeability The cell membrane regulates what can pass in or out of the cell. – this maintains a stable internal environment (homeostasis) – Factors that determine a substances’ ability to pass thru the membrane: Size Shape Composition Polarity (polar or nonpolar) Charge (positive or negative)
Solutions Solution= combination of solute and solvent – Solute= Substance being dissolved – Solvent= thing substance is dissolved in Universal solvent= water *Solute dissolves in the solvent Example: Saltwater
Concentration Amount of solute compared to the amount of solvent – Low concentration of solute Lesser amount of solute dissolved – High concentration of solute Higher amount of solute dissolved
Particle Movement Brownian motion- constant random motion of all particles.
Passive Transport Movement that does not require energy – No energy needed from the cell Types: – Diffusion – Facilitated Diffusion – Osmosis
Diffusion Movement from high to low concentration. – Concentration Gradient= A difference in concentration (A concentration gradient is when there is a difference in concentration within a system) – Particles will move until concentration is equal throughout the system (Dynamic Equilibrium)
2.Ion channels – A tube for dissolved ions to pass thru the lipid bilayer. Ex. Na + ion channel
Osmosis The diffusion of water. – High to low concentration of water – Water will move in the opposite direction of the solute Types of solutions: 1. Hypertonic solution- lower concentration of water outside the cell. water will rush out of the cell – Causes wilting in plant cells.
Hypotonic Solution Solution with a higher concentration of water than the cell. – water will move into the cell causing it to swell Can cause bursting of animal cells
Isotonic solution Equal concentration of water in the solution and the cell. – net movement of water and solute is equal – cell is in dynamic equilibrium w/ the solution http://www.youtube.com/watch?v=7-QJ- UUX0iY http://www.youtube.com/watch?v=7-QJ- UUX0iY
Osmotic pressure Which way will the water move?
How Cells Deal with Osmosis How do cells like paramecium that live in water, not blow up? – Contractile vacuoles – organelles that remove water from the cell.
Questions 1.Can things always diffuse in and out of the cell when they want to? – In your answer, use the words: selectively permeable passive transport. 1.Give a short description (in your own words) of the three types of passive transport.
Active Transport Movement of substances that requires cell energy. – Movement from low to high concentration – Necessary to maintain homeostasis
Proteins Pumps Proteins that force particles to move –E–Energy is used to change the shape of the protein. –e–ex. Na+/K+ ion pump Uses energy to keep a high concentration of Na+ outside the cell and K+ inside the cell. http://www.youtube.com/watch?v=P- imDC1txWw
Endocytosis Ingesting large particles or large amounts of solution. – membrane pinches off around material creating a vacuole – Types Pinocytosis- ingesting large amounts of fluid or solutes. Phagocytosis- ingesting large particles or whole cells. – ex. White blood cells, Ameoba
Exocytosis Release of large particles from the cell – excretory vesicles fuse w/ the cell membrane releasing the material outside the cell. http://www.youtube.com/watch?v=DuDmvlb pjHQ http://www.youtube.com/watch?v=DuDmvlb pjHQ