PCB3743 Vertebrate Physiology Summer 2014 Exam 1 Study Guide Exam 1 will be given Wednesday May 21 at 9 30am in King 1024 usual time place Page numbers are given for both 13th edition and 12th edition of Fox chapter section and gure numbers are the same for both editions I think Exam 1 will cover lectures 1 7 Fox Chapters 6 7 12 and 8 The exams will cover the topics discussed in lecture with additional details drawn from the textbook chapters Topics not covered in lecture will not be on the exam as noted below Remember that the lecture slides and recordings of the lectures are posted for your review on Blackboard The exam format will be 60 multiple choice ll in the blank matching questions using scantronics forms You will have 75 minutes the full lecture period to complete the exam Membrane Transport Lecture 1 Chapter 6 1 Understand the processes of diffusion and osmosis Diffusion Due to random movement thermal energy solute molecules will show net movement from a region of high concentration to a region of low concentration Solute moves down its concentration gradient High solute concentration low solute concentration The rate of diffusion Increases with temperature Increases with concentration gradient Increases with surface area of membrane o o o o Decreases with distance Diffusion is only efficient at 100 m or less If the solute molecules can penetrate the membrane diffusion can occur o Nonpolar molecules Lipids steroids o Small gas molecules O2 CO2 O2 diffuses into cell CO2 diffuses out of cell o Ions the membrane Channels must be open Can move down concentration gradient through protein channels in 1 PCB3743 Vertebrate Physiology Summer 2014 Exam 1 Study Guide Osmosis Diffusion of water across a semipermeable membrane through aquaporin channels from a solution with a low solute concentration to a solution with a high solute concentration Water moves down its concentration gradient from a region of high water concentration to a region of low water concentration o The region with a higher solute concentration is less dilute has less water water o The region with a lower solute concentration is more dilute has more Water will continue to diffuse across the membrane until o The solute concentration is the same on both sides of the membrane 2 PCB3743 Vertebrate Physiology Summer 2014 Exam 1 Study Guide o Physical pressure stops the flow Osmotic Pressure A measure of the force required to stop osmosis that indicates how strongly a solution draws water by osmosis o The greater the solute concentration of a solution the greater its osmotic pressure More solutes more pressure o Pure water has an osmotic pressure zero 0 Isotonic Equal osmotic concentration on each side of the membrane Hypotonic Less concentrated solution lower osmotic pressure Hypertonic More concentrated solution higher osmotic pressure o Ex Distilled water o Ex Seawater Osmolality Osm The osmotic concentration of a solution determined by the number of particles in the solution o Osmolality Osm of particles in moles Liter of water 2 What are the mechanisms of carrier protein mediated transport across the cell membrane Properties of Carrier Mediated Transport Carrier proteins interact only with specific molecules o Ex Glucose transporters transport glucose but not fructose As the concentration of a transported molecule is increased its rate of transport will also increase but only up to a transport maximum Tm o Concentrations greater than the transport maximum do not produce further increase in the transport rate Indicates the carrier transport is saturated Closely related molecules can compete for transporters on the cell surface 3 PCB3743 Vertebrate Physiology Summer 2014 Exam 1 Study Guide o Two molecules that are transported by the same carrier compete with each other The rate of transport for each is lower when they are present together than it would be if each were present alone Facilitated Diffusion Transported molecule is moved down its concentration gradient with no extra energy ATP required Uses potential energy of the concentration gradient Ex Diffusion of glucose from the blood across plasma membranes o GLUT Glucose transporter o Requires using a limited number of transporters o Transport can be regulated by increasing or decreasing the number of transporters 4 PCB3743 Vertebrate Physiology Summer 2014 Exam 1 Study Guide Active Transport Movement of molecules and ions against their concentration gradients from lower to higher concentrations Primary Active Transport Membrane carrier protein is an ATPase that breaks down ATP to release energy o Hydrolysis of ATP is directly responsible for the function of the carriers o Energy is used to transport the molecule against its concentration gradient o Ca2 ATPase Pump Hydrolysis of ATP release of ADP causes conformational change in transporter releasing Ca2 outside the cell into the extracellular fluid o Na K ATPase Pump 3 Na ions bind to inside of carrier protein ATP is hydrolyzed Release of ADP moves 3 Na to outside of cell Release of Pi moves 2 K inside of cell 3 Na out 2 K in for every 1 ATP molecule 5 PCB3743 Vertebrate Physiology Summer 2014 Exam 1 Study Guide Secondary Active Transport Coupled Transport The energy needed for the uphill movement of a molecule or ion is obtained from the downhill transport of another molecule into the cell o Cell uses energy to establish steep concentration gradient for molecule 1 Ex Use Na K ATPase pump to set high Na outside of cell o Co transporter allows molecule 1 to move down its concentration gradient gradient o Couples energy of first molecule to co transport molecule 2 up against its Ex Concentrate glucose inside cell o Cotransport Symport Both molecules move in same direction Ex Na glucose move into cell simultaneously o Countertransport Antiport Molecules move in opposite directions One molecule moves into the cell while the other molecule moves out of the cell 6 PCB3743 Vertebrate Physiology Summer 2014 Exam 1 Study Guide Bulk Transport Transport of molecules i e polypeptides proteins that are too large to be transported through a membrane by carriers Called bulk transport because many molecules can be moved at the same time Exocytosis The fusion of a membrane bound vesicle that contains the cellular products with the plasma membrane o Bulk transport out of the cell Endocytosis Molecules taken into the cell o Bulk transport into the cell 3 Be able to recognize if transport is mediated by carrier proteins and
View Full Document
Unlocking...