Inter and Intra Molecular Interactions Flashcards
Biochemistry relies on covalent or noncovalent molecular interactions?
noncovalent
Is covalent or non-covalent stronger?
Covalent
T/F: noncovalent molecules are bigger and not additive
F, they’re smaller and additive
Examples of noncovalent interactions:
- charge charge interactions
- van der waals forces
- dipole dipole interactions
- london dispersion forces
Charge charge interactions follow which law?
Coulomb’s law
F=k(q1q2/er2)
Common ions in the human body are…
- Ca2+
- Na+
- K+
- Mg2+
- Cl-
- HOPO42-
Energy of interaction is the amount of E needed…
to separate the two charged particles
Higher the dielectric constant =
weaker the interaction between charges
T/F: a salt bridge is the simplest charge-charge interaction
T
Dehydration alters
H bonding network b/c less water
Net result of dehydration is…
increased strength in charge-charge interactions at same distance
Major way ethanol effects charge-charge interactions:
contributes to dehydration
Minor way ethanol effects charge-charge interactions:
- high amounts of ethanol would alter the medium, which will strengthen electrostatic interactions
Dehydration would lead to a higher/lower dielectric constant
lower
Lower dielectric constant alters ion reactions b/c…
oppositely charged ions would have greater attraction and be less available for reactions
H bonds are the interactions between…
a covalently bonded H on a donor group and a pair of bonded e- on acceptor group
H bonds are partially…
dipole-dipole interaction and covalent
H bonds are important in biochem b/c…
of the quantity (a lot)
H bonding stabilizes…
structural elements
Permanent dipole dipole interactions results from…
differences in electronegativity between atoms
- unequal e- distribution
Induced dipole results when…
molecules are near a charge
Dipole dipole has a slight _____ on each end of the molecule
charge
London dispersion forces is the _____ interaction
weakest
Van der waals radius is the…
effective radius for closest molecular packing
T/F: water is the primary solvent for life
T
Water makes up __ - __ % of total body weight
60-75%
Water is found in the highest percentages in the…
- brain
- kidney
- muscle
- blood
Biological functions of water:
- solvent: used in transport and mobility
- reactant: for hydrolysis and hydration of = bonds
- lubricant
- osmoregulation
- supports existence of biological ions
- mediates body temp
Properties of water:
- LMW for room temperature liquid
- H bonds form between water molecules
- high heat capacity
- high heat of vaporization
- less dense when frozen
- high viscosity
- cohesive
- high dielectric constant (ion-dipole interactions)
Why does water have a high heat capacity?
b/c dipole dipole interactions reduces movement as it absorbs E, therefore cools body
Def of heat capacity:
of heat units needed to raise the temperature of body by one degree
Why does water have a high heat of vaporization?
b/c of dipole dipole interactions
- prevents dehydration and decreases body temp
Def of high heat of vaporization:
amount of E (enthalpy) needed to turn liquid into gas
Amphipathic molecules has both:
hydrophobic and hydrophilic properties
Example of amphipathic molecules are…
- fatty acids
- lipids
- detergents (synthetic lipids)
Amphipathic molecules make three formations in water:
- monolayer
- micelles
- bilayer
Arrangement of monolayer?
molecules align at the surface of the liquid in a single layer
Arrangement of micelles?
molecules align in spherical organization with tails facing inward
Arrangement of bilayer?
molecules align in two layers w/ tails facing inward
- leaves hydrophilic surfaces on both outside and inside
What is the clathrate structure?
“cage” of water molecules surrounds nonpolar solute
- create hydrophobic effect
- decreases entropy
Hydrophobic effect stabilizes protein structure by…
driving apolar side chains on amino acids together
ICF makes up how much of body water?
2/3
ICF makes up how much of body weight?
40%
ICF is a solution made up of…
K+, organic anions, and proteins
T/F: ICF is homogeneous in body
F
What controls the constituents of ICF?
metabolism and cell membranes
ECF makes up how much of body water?
1/3
ECF makes up how much body weight?
20%
ECF is a solution made up of…
NaCl and NaHCO3
ECF has three subcompartments:
- ISF: surrounds cells
- plasma: circulates as extracellular component of blood
- transcellular fluid: outside normal compartments
T/F: fluid compartments are not in osmotic equilibrium
F
Osmotic pressure:
hydrostatic pressure produced by a solution in a space decided by a semipermeable membrane due to differential in [ ] of solute
Osmole:
non-SI unit of measurement that defines the # of moles of a chemical compound that contributes to osmotic pressure
Osmolality:
measure of osmoles of solute/kg of solvent
