Test Review Slides PDF

Unit Test Review Cell Membrane, Passive Cell Transport, Active Cell Transport Cell Membrane The Cell Membrane ► Also known as the Plasma Membrane ► Found in ALL CELLS ► Semipermeable & Selective - it controls what enters & exits the cell ► Functions: ► Controls what enters and e...

Unit Test Review Cell Membrane, Passive Cell Transport, Active Cell Transport Cell Membrane The Cell Membrane ► Also known as the Plasma Membrane ► Found in ALL CELLS ► Semipermeable & Selective - it controls what enters & exits the cell ► Functions: ► Controls what enters and exits the cell ► Maintain an internal balance called homeostasis ► Provides protection and support for the cell ► Allows for recognition & communication among cells Structure of the Cell Membrane ► Fluid & Flexible (Fluid Mosaic Model) ► Lipid Bilayer: ► 2 layers of phospholipids ► Phosphate head is polar HYDROPHILIC ► “Likes (attracts)Water” ► Fatty acid tails non-polar HYDROPHOBIC ► “Hates (repels) Water” Be Able to Draw the Cell Membrane & Its Structural Components Components of the Cell Membrane ► (1) Transport Proteins ► - help get materials that are large or charged across the membrane ► Ex. Glucose, K+, Na+,Cl- ► Remember, if you see a plus or mimus (+/-), it indicates a positive or negative charge and therefore, requires a transport protein. ► (2) Glycolipids & Glycoproteins ► Cell Recognition (think nametag) has attached carbohydrate chain ► (3) Cholesterol ► Helps to stabilize the membrane Components of the Cell Membrane: Membrane Proteins ► Integral – Found embedded in the membrane ► Transmembrane an integral protein that goes all the way through the membrane ► Peripheral – off to the side Passive Transport: Three Types 1. Simple Diffusion – diffusion directly across the cell membrane (phospholipids). Oxygen & Carbon Dioxide. 2. Facilitative Diffusion – diffusion with the help of transport proteins. Materials such as glucose & ions. 3. Osmosis - The diffusion of ONLY water. Remember! Water will follow the higher solute concentration! Passive Transport: Diffusion ► Diffusion: random movement of particles from an area of high concentration to an area of low concentration. ► Passive transport continues until all molecules are evenly spaced (equilibrium is reached)-Note: molecules continue to move in equal & opposite directions ► A simple example is making tea Passive Transport: Facilitated Diffusion ► Facilitated diffusion: diffusion of specific particles through transport proteins found in the membrane ► Transport Proteins are specific – they “select” only certain molecules to cross the membrane ► Transports larger or charged molecules Passive Transport: Osmosis ► Diffusion of water from low solute to high solute. Water will follow the solute! (salt) ► Plants love hypotonic solutions ► Human cells love isotonic solutions. ► Hypotonic: Cell will swell and may explode ► Isotonic: Cell will function normally. ► Hypertonic: The cell will shrink and/or crenate ► Hyper = Above Normal ► Hypo = Below Normal ► Iso = Same/Similar Key Terms in Osmosis ► Solution – a mixture made of a solute and solvent ► Solvent – the material that does the dissolving (ex. Water) ► Solute – the material that is dissolved ( ex. Sugar) ► Concentration – the amount of solute per amount of solvent ► Concentration Gradient– a difference in concentration on both sides of the membrane ► Equilibrium – equal concentration on both sides of the membrane ► Net Movement – the direction that the majority of particles are moving Active Cell Transport  Transport that Adenosine requires energy in the Triphosphate What is form of ATP Active Uses ATP to move Transport particles against the concentration Low to High Concentration gradient  (1) Protein Pumps Transports protein against the concentration gradient (1) Primary Active Transport 2 Types of (2) Secondary Active Transport Active (2) Bulk Transport Large amounts of material move in/out of the cell Transport (1) Endocytosis: Taking material INTO the cell Phagocytosis – Cell eating Pinocytosis – Cell drinking (2) Exocytosis: Forcing/Ejecting material OUT OF the cell.  Transports protein against the concentration gradient (low to high concentration) (1) Protein Primary Active Transport: Sodium – Potassium Pump Pumps Secondary Active Transport: Uses the energy from primary active transport (1) Protein Pumps: Primary Active Transport Directly uses ATP to move molecules across a membrane against its concentration gradient. Sodium-Potassium Pump, Na+/K+ pump (1) Primary: Sodium Potassium Pump ► 3 Na+ (sodium) out of the cell, 2 K+ (potassium) into the cell. ► This process is important for muscle contraction, and the brain’s ability to send electrical signals. ► This process generates a difference of electrical charge across the cell membrane, this electrochemical gradient change is used in secondary active transport. (1) Protein Pumps: Secondary Active Transport ► Indirect use of ATP ► Move molecules against their electrochemical gradient (2) Bulk Transport ► Endocytosis (Into the cell) ► Pinocytosis (cell drinking) ► Phagocytosis (cell eating) ► Exocytosis ► EXIT of material from the cell  (2) Bulk Transport – Endocytosis (Phagocytosis and Pinocytosis) Examples of Phagocytosis Examples of Pinocytosis 1. Immune system: White blood 1. Digestion: Intestines cells eat pathogens like absorbing nutrients such as bacteria. vitamins and fluid. (2) Bulk Transport Exocytosis Examples of Exocytosis 1. Expelling waste from the cell 2. Secreting hormones 3. Releasing neurotransmitters