1. What are 3 driving forces across the membrane?
    • Chemical Force: Higher concentration to lower 
    • Electrical force: Opposite charge attracts while same charge repels 
    • Electrochemical force: Combination of both chemical and electrical
  2. What are 5 types of transport?
    • Simple diffusion 
    • Facilitated diffusion 
    • Diffusion through channels 
    • Primary active transport
    • Secondary active transport
  3. What factors affect Simple Diffusion?
    • Lipid solubility 
    • Concentration gradient 
    • Surface Area 
    • Particles with small size and regular shape 
    • Membranes with relatively thin wall
  4. What factors affect Facilitated Diffusion?
    • Rate of transport of each carrier 
    • Number of carriers 
    • Concentration Gradient
  5. Function: Uses ATP directly for molecule transport (to push from low to high concentration)
    Primary active transport
  6. Function: Uses electrochemical gradient for molecule transport
    Secondary transport
  7. When 2 molecules are moving in the same direction in Secondary active transport, this is called
  8. When 2 molecules are moving in different direction in active transport this is called
  9. Definition: Diffusion of water through a membrane, always passive, unaffected by electric charge on cells
  10. Definition: same concentration (no net water movement, cell will remain the same)
  11. Definition: higher concentration (water gets out of cells, causing it to shrink)
  12. Definition: Lower concentration (water gets in, causing the cell to swell or burst)
  13. Function: Molecules enter the cells by vesicle formation
  14. Function: Molecules are packaged into secretory vesicles inside the cell and released into the extracellular fluid
  15. Endocytosis + Exocytosis =
  16. 3 factors affecting the strength of response
    • Messenger 
    • Receptor 
    • Affinity
  17. What happens in Upregulation?
    Receptor # increases
  18. What happens in down-regulation?
    Receptor # decreases
  19. What are 3 types of Chemical messanger?
    • Paracrines: Target neighboring cells  
    • Neurotransmitters: Communication between neuron and target cell (released from Neurons)
    • Hormones: travels through blood to target cell (released from endocrine gland)
  20. Function: Receptors are found in the cytosol or nucleus 
    Binding of receptor will result in gene activation or deactivation
    Intracellular-Mediated Response
  21. Signal transduction consist of
    • Intracellular mediated response 
    • Membrane bound receptor mediated response
  22. Three type of membrane bound receptors
    • Channel linked receptors 
    • Enzyme linked receptors 
    • G protein coupled receptors
  23. Function: ligand binding causes the ion channel to open or close
    Channel linked receptors
  24. Function: Ligand binding activaties the enzyme which will trigger cell response
    Enzyme-linked receptors
  25. Function: 
    Opening or closing of ion channels 
    Activating second messenger system
    GPCR (G protein coupled receptors)
  26. Channel linked receptors are
    • fast ligand-gated channels...
    • receptors & channels are on the same protein
  27. Enzyme linked receptors have...
    receptor and enzyme on the same protein
  28. G- protein coupled ion channles are...
    • slow ligand gated channes 
    • receptor and channel have different proteins
  29. Second messenger is also known as
    • Intracellular messenger
    • the G protein activates the amplifier enzyme which amplifies second messenger production
  30. Steps in cAMP second messenger system
    • 1st msngr binding activates the g protein 
    • Ga subunit will then activate adenylate cyclase 
    • Adenylate cyclase convert ATP to cAMP 2nd msnger 
    • cAMP activates protein kinase A 
    • Protein kinase A transfer a phosphate group from ATP to a target protein 
    • Phosphorylated protein will have an altered activity 
    • Termination
  31. How does termination of Second messenger system occur
    cAMP is degraged by cAMP phosphodiesterase
  32. What enzyme speeds up cAMP amplification?
    adenylate cyclase
  33. What is the advantage of having 2nd messenger?
    • Signal amplification 
    • each step recruits more participants 
    • small amounts of ligand can trigger a huge response
Card Set
Physio test 1