Ch.7 – Cellular Structure and Function 7.1 – Cell Discovery & Theory Cellular Discovery Timeline Cellular Discovery Timeline

Surface Area to Volume Ratio Why are cells so small?? 3cIwJ:colgurchemistry.com/Sc10/Sc10BIOLOGY/PDFS/Sc10BiologyAct10SurfaceAreaVolumePDF.pdf+cell+surface+area+activity&hl=en&gl=us&pid=bl&srcid=ADGEESiazsuguvEmmp1KXAJhcYFOzsFfua2 00s75SY7fYU5wnHpcPGBcRmzf_n9jS4yQEGo9GBk2YBo9LoJq_R0eiuWdLpdm7prBcGXNUv-6IqiZRsgcrHj029YpizX-PEpppWpnuyNR&sig=AHIEtbSM1_pw7JehC0bArlwBXc_4wXlJfQ Ch.7 – Cellular Structure and Function 7.1 – Cell Discovery & Theory

Cell Types Prokaryotes Eukaryotes Bacteria Plant Animal Ch.7 – Cellular Structure and Function 7.1 – Cell Discovery & Theory

Are much more diverse in both habitat and metabolism Are usually single-celled. Differentiation into different cell types almost never occurs. Have no separate nucleus. The cell is surrounded by a membrane, and cell wall but there are no internal membranes. (Few organelles) Ch.7 – Cellular Structure and Function 7.1 – Cell Discovery & Theory Prokaryotes

Ch.7 – Cellular Structure and Function 7.1 – Cell Discovery & Theory Eukaryotes Plant Cells Animal Cells Cell Wall Chloroplasts Large Vacuole More geometric shape Cells with a nucleus and membrane-bound organelles Centrioles Lysosomes More spherical shape

Ch.7 – Cellular Structure and Function 7.2 – The Plasma Membrane The Cell Membrane Cell Membranes are Selectively Permeable and are primarily made up of phospholipids Organelle/Membrane interactive animation

Ch.7 – Cellular Structure and Function 7.2 – The Plasma Membrane The Cell Membrane Other Parts Cholesterol Makes the lipid bi-layer less fluid Glycolipids & Glycoproteins Carbohydrates attached to proteins or lipids and used for cell recognition (Antigens) Proteins Used to transport molecules across the cell membrane (among other uses)

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Cellular Transport So, just how does stuff enter and exit cells? H 2 O, CO 2 and small ions freely cross the cell membrane following the natural laws of diffusion Molecules move from areas of high concentration to areas of low concentration This is called … moving with or down the concentration gradient Diffusion continues until Equilibrium is reached

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Water is special…. The diffusion of water, across a membrane, down the concentration gradient is called OSMOSIS A simple rule of osmosis is that SOLUTES SUCK Solutes, concentrated inside or outside of the cell, will draw the water in that direction

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport 10% 20% 10% 5% 10% Hypertonic Hypotonic Isotonic

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Hypertonic Hypotonic Isotonic What will happen to these cells?

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport The artificial cell is permeable to water and monosaccharides only 1.Draw this diagram 2.Draw a solid arrow to indicate which direction the solutes will move. 3.Is the solution Hyper-, Hypo-, or Isotonic Glucose H2OH2O Fructose 4. Draw a dashed arrow to show the movement of water 5. Will the artificial cell become more flaccid, turgid, or stay the same? Hypotonic Turgid

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Transport proteins allow Facilitated Diffusion to occur They create a tunnel that allows specific substances to cross the bilayer down the concentration gradient They are specific to one substance They are used for large molecules or to increase the diffusion rate of important substances (water & glucose)

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Passive TransportActive Transport Diffusion Osmosis Facilitated Diffusion Requires NO ENERGY Substances move WITH the concentration gradient Requires ENERGY Substances move AGAINST the concentration gradient Protein Pumps Endocytosis Exocytosis

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Protein Pumps Carrier Proteins that use ATP (energy) to move molecules into or out of the cell against the concentration gradient Example: Sodium/Potassium Pump Na/K pump animation IN OUT

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Endocytosis Cells take in molecules by forming vesicles at the cell membrane Phagocytosis Pinocytosis The cell “gulps” liquid material The cell engulfs solid material 2 Types

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Exocytosis Cells excrete molecules by fusing vesicles to the cell membrane Endo- / Exocytosis Animation

Ch.7 – Cellular Structure and Function 7.4 – Cellular Transport Identify the following: 1. Protein Pump 2. Diffusion 3. Facilitated diffusion