Week 3-4

• What is a mole?


  A unit of quantity.
• What is an isotope?

  An isotope is a variant of an element that has the same number of protons but a different number of neutrons.
• How much is a mole of an ELEMENT?

  6.022 x 10^23 atoms
• How much is a mole of a COMPOUND?

  6.022 x 10^23 molecules
• What is avogadros number ?

  the conversion factor between daltons(amu) and grams.
• What is Molarity(M)?


  the number of moles of a substance dissolved per liter of a solution.
• What is the 1st important molecular properties that make H2O important in biology?

  Frozen water floats on liquid water, so it prevents from everything freezing and traps heat so organisms can survive.
• What is the 1st important molecular properties that make H2O important in biology?

  Water molecules have slight polarity
• What is the 3rd important molecular properties that make H2O important in biology?

  Polarity of water molecules allows them to hydrogen bond to each other
• What is the 4rth important molecular properties that make H2O important in biology?

  Hydrogen bonding between water molecules allows for cohesion and surface tension.
• What is surface tension?

  A measure of the force needed to stretch or break the surface of a liquid.
• What are some examples of cohesion caused by hydrogen bonds that are important to biology?

  It allows for water to get to the top of a plant, and allows some animals to stand/run on water.
• What is the 5th important molecular properties that make H2O important in biology?

  Water withstands changes in surrounding temperature.
• What is the specific heat of water?

  1 calorie per gram per celsius. (1cal/g/C)
• If water has an [H+]=10^-7 , what is the pH(molar)?

  7
• How can you calculate pH given Hydrogen concentration?

  pH=-log[H+]
• In any aqueous solution, [H+] x [OH-]=10^-14
• What happens to the pH as [H+] increases?

  Decreases
• What is the physiological pH of a person?

  7.5
• If OH- goes up what happens to the OH3?

  It goes up(?)
• What is a milli?

  10^-3
• What is a micro?

  10^-6
• What is a nano?

  10^-9
• What is a pico?

  10^-12
• Can a human live if the blood pH rises to 7.8?

  No
• What does the body do to maintain the body pH around 7.4?

  Utilize buffers.
• What are buffers?

  they accept H+ ions when they are in excess and donate hydrogen ions when [OH-] becomes high.
• What did Stanley. Miller at Univ. of Chicago do to understand how molecules of life originated on earth?

  He created a lab model system of the chemical conditions on earth, by combining H2O, H2, NH3, CH4 and applied lighting, yielding some amino acids.
• Why is carbon the backbone of biological molecules?

  It can form 4 bonds, C forms covalent bonds which are hard to break in water, and they can form multiple complex chains & structures.
• Why is carbon the main backbone and not silicone?

  It is the smallest atom that has 4 valance electrons.
• What is another name for fat?

  Glycerol
• What is Glycogen?

  Glycogen is a chain of glucose that serves as a storage form of glucose in animals.
• What are the 4 main aspects that can vary in carbon chains?

  lenght, # and positions of branches, presence/absence of ring structures, number and positiong of double bonds.
• What makes carbon skeletons reactive with other molecules or water soluble?

  hydrophilic functional groups
• What are the main functional groups?

  Hydroxyl, amine, aldehyde, ketone, sulfhydryl , carboxylic acid, phosphate.
• Hydroxyl

  H

  
• Amine


  A

  
• Aldehyde

  A

  
• Ketone

  K

  
• Sulfhydryl

  S