Bio Quiz 1 9 25 7.3 PDF

12/23/24 Selective permeability -​ Selective permeability- The cell membrane controls what goes in and out of the cell -​ Diffusion- the movement of particles from an area of higher concentration to an area of lower concentration. -​ This movement is random, particl...

12/23/24 Selective permeability -​ Selective permeability- The cell membrane controls what goes in and out of the cell -​ Diffusion- the movement of particles from an area of higher concentration to an area of lower concentration. -​ This movement is random, particles collide with each other and spread out. Results of diffusion -​ Particles evenly distributed Dynamic equilibrium -​ Continuous movement but no overall change. -​ The cell does not use energy (random movement) Osmosis- -​ Osmosis- Diffusion of water through a selective permeable membrane -​ Water moves from low concentration to high {} (bracket mean concentration) -​ Water uses “aquaporins” water channel proteins -​ Water will move until it reaches dynamic equilibrium 3 types of H2O solutions 1.​ Isotonic- A solution in which the {} substances (solute) is the same outside the cell as the inside of the cell. a.​ Ex. medicines 2.​ Hypertonic- A solution in which the {} of substances is higher outside the cell than the {} inside the cell a.​ Osmosis will cause water to leave the cell. b.​ Diffusion will cause the substances to move inside the cell. c.​ Cells will shrivel, because of decreased pressure. (osmotic pressure) i.​ Ex. dry meat, grape - raisin 12/30/24 3.​ Hypotonic- A solution in which the {} of substances is lower outside the cell, then the {} inside the cell. a.​ Osmosis will cause water to enter the cell. b.​ Diffusion will cause the substances to leave the cell. c.​ The cell swells and internal pressure increases. Turgor Pressure- the pressure that exist in the cell -​ In animal cells the pressure could cause the cell to burst. -​ In humans our cells are bathed with blood that's isotonic. -​ In plant cells it gives shape and support Passive transport- movement of molecules across the membrane without the cell using any energy. (random movement of particles) -​ Ex. diffusion and osmosis Passive Transport by Proteins Facilitated diffusion- the transport of materials across a cell membrane by transport proteins. -​ Ex. sugar 1/2/25 Active transport -​ Active transport- Transport of material against a {} gradient -​ From low to high {} -​ Requires energy -​ Ex. Mineral (Ca, K, Na ions) Endocytosis (type of act. trans.)  -​ Endocytosis- A cell surrounds and takes in material from its environment -​ That portion of the cell membrane breaks aways as a vacuole inside the cell. -​ 2 types 1.​ Phagocytosis(cell eating) - Movement of large particles or whole cells a.​ Ex. Amoebas eat this way b.​ White blood cells “eat” damaged cells 2.​ Pinocytosis- Transport of liquid a.​ Pockets (infolding) on the cell membrane, fill with liquid and pinch off to form vacuoles in the cell. Exocytosis -​ Exocytosis- Used to expel waste. -​ Uses energy -​ Vacuole fuses with cell membrane and the contents are released outside the cell