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What is a polar molecule?
A polar molecule is one in which one end is partially positive and the other partially negative.
What are the 3 types of non-covalent bonding?
- Ionic interactions
- hydrogen bonding
- Van der Waals
What are the 3 types of Van der Waals bonding?
- dipole-induced dipole
- induced dipole-induced dipole
What is an ionic interaction?
Ionic interactions occur between charged atoms or groups.
What is Hydrogen Bonding?
Water molecules hydrogen bond with each other. Four bonding attractions occur.
What is the heat of vaporization?
Energy to vaporize 1 mole of water at 1 atm
What is heat capacity?
Energy to change temperature by 1 degree C
What are nonpolar molecules?
Nonpolar molecules have no polar bonds or the bond dipoles cancel due to molecular geometry. These molecules do not form good attractions with the water molecule. They are insoluble and are said to be hydrophobic (water hating).
What is a hypotonic solution?
When there is too much salt on the outside of the cell, so the cell losses water and shrinks.
What is the Lowry-Bronsted acid?
The proton donor
What is the Lowry-Bronsted base?
The proton acceptor
The Henderson-Hasselbalch (HH) equation is derived from?
The equilibrium expression for a weak acid.
What is a buffer?
A solution that resists change when a small amount of strong acid or strong base is added.
What is the primary buffer within cells?
What is a Zwitterion?
A compound with both positive and negative charges.
What is the inflection point?
Equal moles of acid are equal to moles of salt
What is the equivalence point?
Equal amounts of acid and base are in a solution
What is thermodynamics?
The heat and energy transformations studied by thermodynamics take place in a system (defined by investigator) connected to the surroundings (the rest of the universe)
What is a closed system?
Energy exchanges between system and surroundings
What is an open system?
Matter and energy exchanged between system and surroundings
What is the first law of thermodynamics?
- Energy is neither created nor destroyed
- deltaE = q+w
- deltaE is the change in the internal energy and is a state function
- q is heat
- w is work
What function at constant pressure, volume, and temperature?
What equation is used to find the change in enthalpy for a reaction?
deltaH reactants = deltaH products - deltaH reactants
- -deltaH is exothermic
- +deltaH is endothermic
What is the Second Law of Thermodynamics?
- With a spontaneous reaction, the entropy of the universe increases.
- deltaS univ = deltaS system + delta s surroundings
What is the most useful thermodynamic function for predicting reaction spontaneously?
Gibbs free energy change (deltaG)
What happens in a spontaneous reaction?
- Free energy decreases
- deltaG is negative energy released by the reaction
- said to be exergonic
What happens in a nonspontaneous reaction?
- Free energy increases
- deltaG is positive energy absorbed by the reaction
- said to be endergonic
What is a coupled reaction?
- Two reactions run as a pair.
- One is endergonic and the other is exergonic.
- Overall it is exergonic and the pair is spontaneous
What provides the free energy to drive most endergonic reactions?
Hydrolysis of ATP
What is an alpha amino acid?
- A carboxylic acid with an amino group on the carbon alpha to the carboxylic acid
- The alpha carbon also has an R group side chain. (except glycine which has two H's)
In amino acids, if the R group is not H, the AA can exist in two ________ forms.
Two amino acids link to form what?
a peptide bond
What 4 groups are amino acids classified into?
At physiological pH, the carboxyl group of amino acids is ________ charges and the amino group is _______ charged
What does the titration curve show?
How the amine and carboxyl groups react with the hydrogen ion
At low pH a nonacidic/nonbasic amino acid is what?
When does the isoelectric point for an amino acid occur?
When there is no net charge