Bio 1201 Exam 2 Gregg Questions and Answers Graded A 2024

transport proteins - are responsible for controlling passage across the membrane fluid mosaic model - The membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids fatty acid tails - nonpolar, hydrophobic fatty acid heads - hydrophilic, polar periphial proteins - bound to the surface of the membrane integral proteins - penetrate the hydrophobic core (ones that span the membrane are transmembrane protiens How do cells recognize each other? - by binding to molecules, often containing carbohydrates, on the extracellular surface of the plasma membrane Glycolipids - Membrane carbohydrates that are covalently bonded to lipids. Hypdrophobic - molecules such as hydrocarbons that can dissolve in the lipid bilayer and pass through the membrane rapidly Hydrophilic - molecules that don't cross the membrane easily (ions and polar molecules) transport proteins - allow passage of hydrophilic substances across the membrane carrier proteins - bind to molecules and change shape to shuttle them across the membrane passive transport - the diffusion of a substance across a membrane with no energy investment Diffusuion - Spreading out of particles away from each other, from an area of high concentration to an area of low concentration. (move to where space is available) concentation gradient - substances diffuse from high concentration----> low concentration Osmosis - Diffusion of water through a selectively permeable membrane Isotonic - when the concentration of two solutions is the same (no net movement) Hypertonic - cell losses water and shrivils hypertonic - cell gains water and expands In a plant cell water moves in and out affecting the size of what? - central vacuole facilitated diffusion - the transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins ion channels - channel proteins that transport ions gated channels - open or close in response to a stimulus active transport - requires energy (ATP) to move substances against their concentration gradient cotransport - coupled transport by a membrane protein transport proteins - small molecules leave through the lipid bilayer via___________? Phagocytosis - Cell eating Pinocytosis - Cell drinking hydrophilic tails - If a plasma membrane were compared to a sandwich, __________ would be considered the filling Metabolism - All of the chemical reactions that occur within an organism active transport - cytoplasm of cell has a higher concentration of k+ ions. How will K+ ions enter the cell? metabolic pathway - Begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product. Energy - the capacity to cause change Law of Conservation of Energy - the law that states that energy cannot be created or destroyed but can be changed from one form to another second law of thermodynamics - Every energy transfer or transformation increases the entropy of the universe. free energy - the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system