MCB 2000 (UCONN) EXAM 1 STUDY GUIDE | BIOCHEMISTRY PRACTICE QUESTIONS AND
ANSWERS | COMPLETE REVIEW
covalent vs. noncovalent interactions- how are they different? - ANS ✔✔
Electronegativity - ANS ✔✔
Polarity - ANS ✔✔Molecules having uneven distribution of charges
polar: unequal sharing, involved an electronegative atom
nonpolar: equal sharing
what is polarity important? - ANS ✔✔-explains why molecules are hydrophilic and hydrophobic
-leads to noncovalent interactions
hydrophobic effect - ANS ✔✔-Inability of water to dissolve nonpolar molecules results in this
important organizing principle.
-nonpolar molecules cannot form H bonds with water
-hydrophobic molecules cluster together in aqueous solutions
-powered by the increase in the entropy of water that results when hydrophobic molecules
come together
*powerful organizing force
what makes hydrophobic interactions favorable? - ANS ✔✔entropy (S)
-drives the interaction between nonpolar molecules
-hydrophobic interactions allow for an increase in entropy of water
entropy (S) - ANS ✔✔a measure of the disorder of a system
, -high: disordered state
-low: ordered state
Phospholipids - ANS ✔✔-have hydrophilic and hydrophobic properties (called amphipathic)
-when exposed to water, form membranes
types of covalent interactions - ANS ✔✔nonpolar, polar
-stable
-do not break and form spontaneously
noncovalent interactions - ANS ✔✔-Hydrogen bonds
-Electrostatic, ionic interactions
-Van der Waals forces
-Hydrophobic interactions
hydrogen bonding - ANS ✔✔
Electrostatic (ionic) interactions - ANS ✔✔-attraction/repulsion
-occurs between atoms with a complete negative charge or a complete positive charge
-strength determined by distance and solvent
*importance: protein-protein interactions, DNA-protein interactions, catalytic mechanisms
dielectric constant - ANS ✔✔high: greater ability to dissolve salts
* water has a high dielectric constant
ANSWERS | COMPLETE REVIEW
covalent vs. noncovalent interactions- how are they different? - ANS ✔✔
Electronegativity - ANS ✔✔
Polarity - ANS ✔✔Molecules having uneven distribution of charges
polar: unequal sharing, involved an electronegative atom
nonpolar: equal sharing
what is polarity important? - ANS ✔✔-explains why molecules are hydrophilic and hydrophobic
-leads to noncovalent interactions
hydrophobic effect - ANS ✔✔-Inability of water to dissolve nonpolar molecules results in this
important organizing principle.
-nonpolar molecules cannot form H bonds with water
-hydrophobic molecules cluster together in aqueous solutions
-powered by the increase in the entropy of water that results when hydrophobic molecules
come together
*powerful organizing force
what makes hydrophobic interactions favorable? - ANS ✔✔entropy (S)
-drives the interaction between nonpolar molecules
-hydrophobic interactions allow for an increase in entropy of water
entropy (S) - ANS ✔✔a measure of the disorder of a system
, -high: disordered state
-low: ordered state
Phospholipids - ANS ✔✔-have hydrophilic and hydrophobic properties (called amphipathic)
-when exposed to water, form membranes
types of covalent interactions - ANS ✔✔nonpolar, polar
-stable
-do not break and form spontaneously
noncovalent interactions - ANS ✔✔-Hydrogen bonds
-Electrostatic, ionic interactions
-Van der Waals forces
-Hydrophobic interactions
hydrogen bonding - ANS ✔✔
Electrostatic (ionic) interactions - ANS ✔✔-attraction/repulsion
-occurs between atoms with a complete negative charge or a complete positive charge
-strength determined by distance and solvent
*importance: protein-protein interactions, DNA-protein interactions, catalytic mechanisms
dielectric constant - ANS ✔✔high: greater ability to dissolve salts
* water has a high dielectric constant
