Bio Exam 2

• Four Levels of Protein Structure

  Primary, Secondary, Tertiary, and Quaternary
• Protein Functions in the human body (8)

  Channels & Pumps, Transport, Structural and Mechanical, Enzymes, Hormones, Antibodies, Fluid Balance, and Acid-Base Balance
• What determines the function a protein will have?

  Protein structure/shape
• Protein Denaturation


  Occurs when the weak bonds that form the secondary and tertiary structure of the protein are broken due to temperature change, ph change, salt concentration, or solvent.
• Protein Renaturation


  A denatured protein going back to a normal protein
• Metabolic Pathway


  Begins with a specific molecule and ends with a product
• Catabolic


  Reactions break down molecules and release energy Ex) Digestion
• Anabolic


  Reactions use energy to synthesis new molecules Ex) Protein-synthesis
• Energy 


  The capacity to cause change. Ex) Thermalenergy - Energy of heat
• Potential Energy


  The energy that matter possesses because of its location or structure.
• Kinetic Energy 


  Energy associated with motion
• Chemical Energy


  Potential energy available for release in a chemical reaction
• Electromagnetic Energy


  Includes light and radio waves. Ex) Xray, Radio waves
• Thermal Energy


  Kinetic energy associated with random movement of atoms and molecules.
• First Law of Thermodynamics 


  Describes the conversion of energy- The total amount of energy before a transformation equals the amount after the transformation
• Second Law of Thermodynamics

  Entropy- After an energy transformation, the amount of energy available to do work decreases, and unusable energy (disorder) increases.
• Entropy


  Measure of disorder
• Spontaneous process 


  Occurs without energy input; can happen quickly or slowly
• Useful Energy


  Energy used to do work
• Cholesterol 


  Helps to Stabilize the structure of the plasma membrane
• How can Phospholipids be recognized

  Can be recognized by the presence of a head and two tails.
• Trasport Protein 


  Protein that allows solute molecules to enter the cell
• Active Transport

  Always against the concentration gradient of the solute
• Passive Transport 


  Always down the concentration gradient of the solute
• How is does the saturation affect the membrane fluidity?

  Unsaturated phospholipids increase the fluidity
• Is the Phospholipid head hydrophilic or hydrophobic?

  Hydrophilic (affinity to water)
• Is the phospholipid tail hydrophilic or hydrophobic?

  Hydrophobic (excluded from water)
• What type of molecule can cross the lipid bilayer EASILY, would they require a portiein?


  Nonpolar Molecules. Ex)Hydrocarbons, O2, CO2.

  This molecule is hydrophobic and DOES NOT REQUIRE A TRANSPORT PROTEIN!!
• Which type of molecules have a DIFFICULTY passing the bilayer, would they require a transport protein?


  Polar Molecules Ex) Water, Sugars

  Ions Ex) Na+, K+, Ca2+, Cl-

  These molecules are hydrophilic, and REQUIRE A TRANSPORT PROTEIN!
• How unsaturated fatty acids keep the membrane fluid at a low temp?

  The double bonds form kinks in the fatty acid tails to prevent adjacent lipids from packing tightly together.
• Water is able to move quickly through the plasma membrane of some cells because....

  Water moves through aquaporin channel proteins
• What happens to molecules as they move down the concentration gradient?

  The molecules move from where they are more concentrated to where they are less concentrated.
• Passive Transport 


  Diffusion across a biological membrane
• Osmosis 


  Process of which water crosses a selectively membrane
• How can you tell if a cell is Hypertonic?

  There is a greater concentration of solute outside of the cell.
• What will happens to a cell when placed into a hypotonic solution?

  The cell will GAINS water causing it to SWELL
• What happens to a cell when placed into a hypertonic solution?

  The cell loses water causing it to SHRINK
• Endocytosis


  Moves material into a cell via membranenous vesicles
• How is a Pinocytosis recognized?

  (cell drinking)

  The cell is engulfing extracellular fluid
• When does phagocytosis occur?

  When a cell engulfs a large particle.