Chapter 3: The Importance of Weak and Strong Chemical Bonds Flashcards
Strong covalent bonds are …
- Strong and stable to hold molecules together
- Do not break spontaneously
- short and covalent
Van der waals, hydrophobic, hydrogen bonding and ionic are all _____ ____
Weak bonds
True or False:
Weak bonds are important to secondary structure of macromolecules
FALSE
Weak bonds are important to TERTIARY structure of macromolecules
Weak bonds can …
- Form and break under physiological conditions (reversible)
- Mediate internal interactions, enzymes/substrate and protein-DNA/RNA/protein interactions
True or False:
Weak bonds are longer than stronger bonds
True
________ is the number of covalent bonds that a given atom can make
Valence
What is the bond angle?
The angle between two bonds originating from the same atom
Explain bond rotation
Single covalent bonds permit free rotations of bound atoms, double bonds do not rotate
Dextrose
Sugar
L-Glucose
Cannot be phosphorylated by hexokinase
A + B –> AB Energy
Spontaneous reaction
Releasing energy. Stronger the bond, greater the amount of energy, thus the more energy needed to break it
AB + Energy –> A + B
Force exist to break bond using temperature or heat
As the temperature of a collection of molecules is increased, the stability of their bonds _________
Decrease
A + B –> AB + Energy
The equilibrium constant is …
[AB] / [A][B]
The ______ the bond, the greater the amount of energy released upon its formation
Stronger
When equilibrium is reached, the number of bonds forming per unit of time _______ the number of bonds breaking
Equals
Endergonic Reaction
+G
Exergonic Reaction
-G (favorable reaction)
True or False:
All molecules can form van der waals
True
Electrostatic attraction
All forms of weak interactions are based on attractions between electrical charges
Hydrogen bonds are _______ than covakent bonds, but _______ than van der waals
weaker, stonger
These types of bonds are directional
Hydrogen bonds
These types of bonds contain one or more units of net charge, can form a salt bridge
Ionic bonds
A weak covalent bond is called …
Disulfide bond
Disulfide bridges are formed by
Two sulfur groups bonded to each other
The weakest bond is called …
Van der waals
Nonpolar molecules aggregate in water because ….
Water has lower disruption and higher entropy when nonpolar molecules are removed
True or False:
Weak interaction require complementary molecular surfaces
True
True or False:
Weak bonds mediate most protein-DNA and protein-protein interactions
True
True or False:
Enzymes increases activation energies for molecular rearrangements
FALSE
Enzymes lower activation energies
ATP hydrolysis is favorable because …
competing resonance between the phosphodiester bonds is relieved
