Cell Transport PDF

Cell Transport Passive and Active Transport Outline: ❏ Materials that can be transported through the cell membrane ❏ Simple Diffusion: Gases and Small Molecules ❏ Facilitated Diffusion: Protein Channels ❏ Osmosis: Different Types of Solution ❏ Active Transport Materials Across the Cell Membra...

Cell Transport Passive and Active Transport Outline: ❏ Materials that can be transported through the cell membrane ❏ Simple Diffusion: Gases and Small Molecules ❏ Facilitated Diffusion: Protein Channels ❏ Osmosis: Different Types of Solution ❏ Active Transport Materials Across the Cell Membrane Materials Across the Cell Membrane 2.) Charge (polar or nonpolar) Characteristics of molecules that affect their ability to cross the cell membrane: 1.) Size (micromolecules or macromolecules) 3.) Solubility (lipid-soluble or not) Passive Transport: Simple Diffusion ❏ It is a natural process where molecules move from a point of higher concentration to areas of lower concentration to attain equilibrium. ❏ It occurs in gases such as oxygen and carbon dioxide. Passive Transport: Simple Diffusion ❏ Not just gases but LIQUIDS too! Factors that Affect Diffusion of Solute within the Solvent: Solute - dissolved substances Solvent - substances that dissolve 1.) Temperature 2.) Pressure Passive Transport: Simple Diffusion 3.) Solvent Density 4.) Solute Solubility - The higher the density of the solvent the slower the rate of diffusion. Nonpolar Solute + Polar Solvent = CANNOT BE Passive Transport: Facilitated Diffusion ❏ It is the movement of molecules from high to low concentration with the help of membrane transport protein. ❏ It occurs in small molecules like glucose, amino acids, and ions. Passive Transport: Facilitated Diffusion ❏ Carrier Protein - undergo temporary binding to the molecule resulting in conformational change that moves molecules. (amino acids and glucose) ❏ Channel Protein - contain tunnels or openings that serve as passageways of molecules. (charged particles - ions) Passive Transport: Facilitated Diffusion ❏ Aquaporins - are water protein channels that allow water molecules to diffuse rapidly into and out of the cells found in areas with high water influx Passive Transport: Osmosis ❏ It pertains to the diffusion/movement of water molecules across a semipermeable membrane. Passive Transport: Osmosis ❏ Water Potential - used to describe the movement of water molecules as they undergo osmosis ❏ Osmotic Pressure - Is the force that moves water molecules through a semipermeable membrane Passive Transport: Osmosis Passive Transport: Osmosis Tonicity - refers to the strength of a solution in relation to osmosis - can either be hypotonic, isotonic or hypertonic solution Passive Transport: Osmosis Hypotonic Solution - happens when a cell is placed in a solution with more water outside the cell than inside its cytoplasm. - more solutes present inside the cell - “hypo” means under results to cytolysis - swelling/bursting of the cell Passive Transport: Osmosis Hypertonic Solution - happens when a cell is placed in a solution with less water outside the cell than inside its cytoplasm. - more solutes present outside the cell - “hyper” means above results to crenation/plasmolysis - shrinking of the cell Passive Transport: Osmosis Isotonic Solution - happens when a cell is placed in a solution with the same concentration of water and other solutes as its cytoplasm - “iso” means the same results to neither shrinking or swelling Passive Transport: Osmosis Osmosis in Plants - When placed in hypotonic solution, water molecules enter vacuoles, causing it to expand, pushing the cytoplasm towards the cell wall. - results to turgidity - When placed in hypertonic solution, plasmolysis (wilting) occurs. Active Transport ❏ It is the movement of molecules across the cell membrane from regions of lower to higher concentration ❏ It requires energy in the form of ATP. ❏ It occurs in the transport of charged particles (ions). Active Transport System: Na+ - K+ Pump ❏ It is a transport system that uses ATP to move a substance, such as an ion, into the cell, and often at the same time, a second substance is moved out of the cell. SUMMARY Simple Diffusion: -spreading of molecules from Materials: high to low concentration -gases, sugar, amino acids, Facilitated Diffusion: proteins and ions -uses membrane transport Characteristic of Molecules: protein to move materials -size, charge and solubility Osmosis: Passive Transport: - movement of water across -no energy required the cell membrane -movement of molecules from Active Transport: high to low concentration - energy is required Types: -movement of molecules from -simple and facilitated diffusion low to high concentration and osmosis Types: sodium-potassium pump - See you on our next synchronous meeting! Stay healthy! Stay alive!