BIO 2

• During diffusion, substances move from an area of high concentration to an area of low concentration. until the concentration becomes equal throughout a space.
• It's true for some substances moving into and out of cells. because the cell membrane is semipermeable, only small, uncharged substances like carbon dioxide and oxygen can easily diffuse across it. Charged ions or large molecules require different kinds of transport
• Osmosis is the movement of water through a selectively permeable membrane from an area of higher water potential to lower water potential.
• Active transport requires energy (ATP) and moves substances up their concentration gradients
• The process by which plants absorb water against its concentration gradient is called active transport
• The process by which water moves from an area of higher solute concentration to an area of lower solute concentration is called osmosis
• Osmosis is a passive transport process during which water moves from areas where solutes are less concentrated to areas where they are more concentrated
• tonicity of solution is hypertonic when the solute concentration is higher solute in solution than in cell. and water moves out of the cell
• tonicity of a solution is the ability of a solution to cause a cell to change shape
• tonicity of solution is isotonic when solute concentration is equal amounts of solute in cell and solution and water moves into and out of the cell at the same time
• tonicity of solution is hypotonic when solute concentration is lower solute in solution than in cell and water moves into the cell
• Isotonic 


  a type of solution

  
• hypertonic 


  a type of solution

  
• Hypotonic 


  A type of solution

  
• in the case of red blood cell, isotonic conditions are ideal, and your body has homeostatic (stability- maintaining) systems to ensure these conditions stay constant. if placed in a hypotonic solution, are red blood cell will bloat up and may explode, while in a hypertonic solution, it will shrivel- making the cytoplasm dense and its contents concentrated and may die
• in the case of a plant cell, a hypotonic extracellular solution is actually ideal. the plasma membrane can only expand to the limit of the rigid cell wall, so the cell wont burst or lyse. in fact, cytoplasm in plants is generally a bit hypertonic to the cellular environment, and water will enter a cell until its internal pressure- turgor pressure- prevents further influx
• maintaining this balance of water and solutes is very important to the health of the plant. is a plant is not watered, the extra cellular fluid will become isotonic or hypertonic, causing water to leave the plant's cells. this results in a loss of turgor pressure, which you have likely seen as waiting. under hypertonic condition. the cell membrane may actuallly detach from the wall and constrict the cytoplasm, a state called plasmolysis
• hypertonic plant solution

  a type of solution

  
• Isotonic plant solution

  a type of solution

  
• Hypotonic plant solution

  A type of solution

  
• facilitated diffusion although gases can diffuse easily between the phospholipids of the cell membrane, many polar or charged substances (like chloride) need help from membrane proteins. membrane proteins can either channel proteins or carrier protein
• this type of membrane protein is channel protein

  
• this type protein membrane is carrier protein

  
• Passive transport is a type of transport that does not require energy to occur
• concentration gradient is a region of space over which the concentration of a substances changes
• Permeability the quality of a membrane that allows substances to pass through it
• equilibrium is the state at which a substance is equally distributed throughout a space
• during active transport, substances move against the concentration gradient, from an area of low concentration to an area of high concentration. this process is "active" because it requires the use of energy (usually in the form of ATP). it is the opposite of passive transport
• active transport requires assistance from carrier proteins, which change conformation when ATP hydrolysis occur
• hydrolysis: the chemical breakdown of a compound due to reaction with water.
• The sodium potassium pump uses ATP to actively transport sodium and potassium across the plasma membrane
• Intracellular fluid has a higher concentration of potassium than extracellular fluid; therefore, there is a net movement of potassium into cells by facilitated diffusion down its concentration gradient
• Extracellular fluid has a lower concentration of potassium than intracellular fluid; therefore, there is a net movement of potassium out of cells by active transport up its concentration gradient