Chemistry Test 2 Flashcards
1
Q
Acid/Base reaction
A
Transfer of protons from one species to another
2
Q
Substitution reaction
A
Switching one group for another.
(Transferase)
3
Q
Elimination reaction
A
Removing a group completely from the molecule.
(Lyase)
4
Q
Addition reaction
A
Adding a group to the molecule.
(Ligases)
5
Q
REDOX reaction
A
Changing the oxidation state of a group on a molecule.
(Oxidoreducatse)
6
Q
Isomerization
A
Rearrangement of groups within the same molecule
(Isomerase)
7
Q
Nucleophile
A
Election rich species (Anions, heteroatoms with one loan pair electrons, alkenes, alkynes)
8
Q
Electrophile
A
Electors poor species (Carbocations, carbonyl groups, Alkenes, alkynes)
9
Q
Catalyst
A
If used, these help to increase the rate at which the reaction occurs (All bio chemicals reactions utilize enzymes and cofactors as catalysts)
10
Q
Reactions favor order or disorder?
A
Disorder
11
Q
Nucleophilic substitution
A
Addition of an electron rich species (nucleophile) to an electron poor species (electrophile).
12
Q
Aromatic substitution
A
Substitution of a hydrogen on an aromatic ring with another group (not oxygen or nitrogen)
13
Q
Acyl substitution
A
Addition of an electron rich species (nucleophile) to a carbonyl containing group (esters, amides, and carboxylic acids), sulfonate group, or phosphate group
14
Q
Going from a positive charge to neutral makes you an Electrophile or Nucleophile?
A
Electrophile
15
Q
Going from a negative charge to neutral makes you an Electrophile or Nucleophile?
A
Nucleophile
16
Q
Oxidation reaction
A
Increases in the number of bonds to O or N
Decreased in the number of bonds to H
17
Q
Reduction reaction
A
Decrease in the number of bonds to O or N
Increase in the number of bonds to H
18
Q
Delta G (Gibs free energy)
A
A measure if a chemical process will or will not work.
19
Q
Change of an enzyme confirmation =?
A
More disorder, which makes the process much more favorable.
20
Q
Spontaneous reactions are ?
A
Favored
21
Q
Non spontaneous reaction are?
A
Not favored
22
Q
Equilibrium will always favor?
A
The weaker acid
23
Q
PKa scale: -20 to 25 is ?
A
Acidic
24
Q
PKa: 30 to 60 are?
A
Not acidic
25
H2O pKa is?
15.6
26
What is the formula to calculate the pH of a strong acid?
pH= -log [(quantity of mol)]
27
What are the equations to calculate the pH of a strong base?
pOH= -log [( quantity of mol )]
Then
pH+pOH=14
28
When dealing with diprotic acids what do you have to take into account when calculating pH?
That the equation is balanced! You will remove a hydrogen twice so you will produce twice the amount of base!
H2SO4 + 2H2O -> 2H3O+ + SO42-
You also have to divide the moles by the coefficient of the acid.
So 2 moles of diprotic acids would really be one mole.
Triprotic acids you would divide moles by 3!
29
When calculating the pH of weak acids/bases what table should you use?
The I.C.E. Table
30
Kb means you have to solve for?
pOH
31
If you have Ka you have to solve for?
pH
32
Does 1g = 1 mL?
Yes
33
Transferase
Transfer functional groups from one substrate to another:
34
Hydrolase
Break bonds using water (hydrolysis)
35
Oxidoreductases
-Catalyze REDOX reactions.
-Catalyzes the transfer of electrons from one substrate (reductant) to another substrate (oxidant)
36
Lyase
Catalyze elimination reactions (Breaks chemical bonds (not hydrolysis or REDOX)
)
37
Ligases
Joining of two molecules together (Forms chemical bonds between two substrates)
38
Isomerases
Catalyze structural shifts (intramolecular group transfer)
39
Saponification
-Conversion of a triglyceride (fats and oils) into fatty acids (lipids)
-Ester to a carboxylic acid
40
What are the three drug properties?
Affinity – how well the drug binds to the receptor
Efficacy – how well the drug produces its desired effect
Potency – term used to compare the relative affinity of competing drugs
41
What are the two classes of antagonists?
1. Competitive – bind reversibly
2. Non-competitive – either binds irreversibly or binds to create allosteric effects that diminish and agonist’s ability to bind to a different receptor.
42
Factors affecting bioavailability include:
Molecular weight of the drug
Drug formulation
Drug stability (especially pH sensitivity)
First pass metabolism: typically in the liver
Blood flow
Gastric emptying: food slows this process
Intestinal motility
Drug interactions
43
What is Lipinski Rule of 5?
Describes drug potential for a new chemical entity (NCE)
Used as a tool to measure a NCE’s potential bioavailability
44
What is Lipinski Rule of 5 based on?
Hydrogen bond donors (typically amines and alcohols)
Hydrogen bond acceptors (total number of N, O, and F)
Molecular weight (MW)
Calculated Partition Coefficient (cLogP)
*Violation of more than one “rule” predicts a NCE is non-orally available*
45
Low MW drugs with a low cLogP can easily cross membranes?
T or F?
True
46
Potential drug compounds must have a mix of hydrophilic and lipophilic groups?
T or F?
True
47
Structural alerts – certain functional groups that have been linked to increased toxicity due to their metabolites which include?
Aromatic anilines
Nitroaromatics
Aliphatic halides
Polycyclic aromatic hydrocarbons
Thiophenes
48
What is the acid-dissociation constant (KA)?
49
pH + pOH = ?
14
50
Strong Acids do what when dissolved in water?
Completely ionize (break apart into ions) when dissolved in water!
51
Weak Acids do what when dissolved in water?
Partially ionize when dissolved in water!
52
Strong Acids have weak conjugate bases.
T or F
T
53
Weak Acids have strong conjugate bases. T or F?
T
54
Strong Bases do what when dissolved in water?
Completely ionize (break apart into ions) when dissolved in water
55
Weak Bases partially ionize when dissolved in water. T or F?
T
56
You have 0.75 M of a weak base. What would the ICE table look like?
57
You have 1.2 M of a weak acid. What would the ICE table look like?
58
The ICE table helps you find the KA of weak acids. What is that formula?
59
If you are given a weak acid, what steps would you do to find the pH?
I.C.E table.
KA formula
Insert KA amount into the equation pH= -log[H3O+]
Then you get your pH
60
If you are given a weak base, what steps would you do to find the pH?
I.C.E table.
KB formula
Insert KB amount into the equation pOH= -log[OH-]
Subtract what you get for pOH from 14.
Then you get your pH
61
How do you calculate Molarity?
mol of solute/L of solution
62
How do you calculate Molality?
mol of solute/kg of solvent
63
How do you calculate weight percent?
Mass of solute/mass of solution X 100 %
64
How do you calculate volume percent?
Volume of solute/volume of solution X 100 %
65
Hydronium H3O+ is acidic or basic?
Acidic.
66
The ICE table helps you find the KB of weak bases. What is that formula?
67
What is the equation for a weak base mixed in water?
(Henderson Hasselbalch Equation)
68
What is the equation for a weak acid mixed in water?
(Henderson Hasselbalch Equation)
69
1 mL = how many cm^3?
1 cm^3
70
How many mL are in 1 L?
1,000mL
71
1 Kg = how many grams?
1,000 g
72
What formula should you use to calculate ionized percent when given a weak acid?
73
What formula should you use to calculate ionized percent when given a weak base?
74
What is surface Tension
-Liquid’s resistance to increase its surface area
-The stronger the intermolecular forces, the more energy required to increase the surface area
-To minimize surface area, liquids form spherical drops
75
What is capillary Action?
-The spontaneous rising of a liquid in a narrow tube or the movement of a liquid up a piece of paper against the pull of gravity
-The result of cohesive (hold the liquid molecules together) and adhesive (attraction of the outer molecules to the container’s surface) forces
76
What is Viscosity?
-Measure of a liquid’s resistance to flow
-The amount of energy necessary to move an object through a fluid
-Molecule size plays an important role (greater potential for more intermolecular force interactions)
77
What are two characteristics of Receptor–Drug Binding
-The vast majority of drug compounds bind to receptors through intermolecular forces rather than through the formation of chemical bonds.
-Determines properties such as efficacy, potency, and, to a limited extent, toxicity
78
What is Solubility?
-Depends, in part, on attractive forces of the solute and solvent
-Substances with similar polarity will be soluble (solid in liquid) or miscible (liquid in liquid) –> “like dissolves like”
79
What are Van Der Waals (London Dispersion) Forces
-Interaction arising from the formation of induced dipoles between two non-polar molecules (or portions of molecules)
-Weakest of the intermolecular forces
80
What are Dipole-Dipole Interactions?
-Occurs in all polar molecules
-Relatively strong interaction, but depends on the nature of individual dipoles involved
81
What is Hydrogen Bonding?
-Very strong, specialized dipole-dipole interaction
-H-bond donors –> molecule providing the hydrogen
-H-bond acceptor –> molecule that attracts the hydrogen
-[X—H - - - :Y] strongest when X and Y are N, O, and F
82
What are Electrostatic Interactions?
-Ionic interactions between a cationic portion and anionic portion
-Effective at distances farther than other types of interactions
-Persist longer than other types of interactions
83
What is a Covalent Bond?
-Strongest interaction
-Limited reversibility
-Seldom formed
84
Identify the drug binding sites that can occur
85
Rank these forces in order from weakest to strongest:
Ion-dipole interactions
Hydrogen bond
Dipole-dipole interactions
Van der Waals forces
Van der Waals forces
Dipole-dipole interactions
Hydrogen bonds
Ion-dipole interactions
86
What does ADME stand for?
Absorption – enter into blood stream
Distribution – contact with receptor
Metabolism – leave receptor and move to liver (or other metabolism site)
Excretion – passage to kidneys for removal
87
What is Active Transport?
Transport of a drug across a concentration gradient
Requires the aid of membrane-bound proteins to recognize the drug for transport
Influx - into the cell
Efflux - out of the cell
Requires energy for the process to work.
At high drug concentrations, transport plateaus due to limited number of transport proteins available
Can lead to competition with structurally similar compounds.
88
What is Passive Diffusion?
Transport across a membrane from area of high concentration to area of low concentration (requires no energy)
Low molecular weight drugs have an easier time crossing membranes
Absorption of drugs into the bloodstream is dependent on the acid/base properties of the drug and the pH at the site of absorption
89
Transport and Drug Distribution is effected by?
Drug Size
Small Drugs (< 50 Da)=Bulk Flow
Lipophilic Drugs (50 – 500 Da)=Passive transport
Drug Charge
Ionized Drugs (> 50 Da)=Active transport
90
What equation do you use to find the pH of blood?
91
Where are acidic drugs better absorbed?
Drug absorption via passive diffusion is directly related to the amount of ionized:unionized drug. Understanding the physiochemical properties of the drug can help to determine if it will be able to cross a particular cell membrane (i.e. acidic drugs are better able to be absorbed in the stomach than basic drugs)
92
Anesthetics are weak bases, this means that?
The majority of local anesthetics are weak bases; therefore, those drugs with a pKa closer to physiological pH will exist in the more lipid-soluble unionized form. This will allow them to better cross the axonal membrane to initiate onset.
93
What are the three main buffer systems?
Bicarbonate, Phosphate, and Protein buffer systems
94
What are four important things about buffers?
Buffers are solutions that contain a weak acid and its conjugate base or a weak base and its conjugate acid.
Buffers resist change in pH when strong acids or bases are added in limited quantity
Each buffer has a limit to the amount of acid/base that can be added before the buffer loses its ability to resist change. This is called the buffer capacity.
Buffers are important for a variety of chemical and biological processes that must occur in a controlled pH range.
95
What is a Lewis acid/base?
Acid – electron acceptor
Base – electron donor
96
What is a Bronsted-Lowry acid/base?
Acid – proton donor
Base – proton acceptor
97
What is Bioavailability
How much of the administered drug is actually absorbed. (typically used for oral administration)
Factors affecting bioavailability include:
Molecular weight of the drug
Drug formulation
Drug stability (especially pH sensitivity)
First pass metabolism (typically in the liver)
Blood flow
Gastric emptying (food slows this process)
Intestinal motility
Drug interactions
98
What is
Pharmacodynamics
The study of the biochemical, physiological, and molecular effects of drugs on the body.
Includes:
Site of Action
Mechanism of Action
Receptor Binding
Postreceptor Effects
Chemical Interactions
Can be affected by:
Disease or Disorder
Age
Drug–Drug interactions
Receptor subtypes include:
Enzymes
Ion Channels
Membrane receptors
Drugs bind due to chemical interactions:
Electrostatic interactions (intermolecular forces)
Hydrophobic interactions
Covalent bonds
Stereospecific interactions (enantiomers)
99
What is Pharmacodynamics?
The study of the absorption, distribution, metabolism, and excretion of drugs from the body.
Concentration affects the ability of the drug to give its desired effect
Helps to better understand the following:
Drug administration
Therapeutic dosing
Time intervals between drug dosing
Toxic dosing
100
What is Absorption ?
Method of drug administration
Enteral (oral) – through the intestines
Parenteral – other than the intestine
Intramuscular
Subcutaneous
Intravenously
Inhalation
Absorption rate determines time to maximal concentration at the receptor to produce peak effect.
Bioavailability – how much of the administered drug is actually absorbed. (typically used for oral administration)
101
What is Distribution?
Effectiveness of the movement of the drug throughout the body
Influenced by
Blood
Total body water
Extracellular fluids
Lymphatic fluids
Cerebrospinal fluids
Protein-binding
Drug solubility properties help determine ability of drug to be distributed to the desired receptor site.
102
What is Metabolism?
Breakdown of drugs into metabolites
Prodrugs – convert from inactive form to active form
Typically inactivates the drug ahead of excretion
Common processes include:
Hydrolysis (esters, amides, and nitriles)
REDOX reactions (Cytochrome P450 enzymes in the liver)
Has the potential to lead to the formation of toxic metabolites
103
What factors are important for a drug to be effective?
Low MW drugs with a low cLogP can easily cross membranes.
Potential drug compounds must have a mix of hydrophilic and lipophilic groups.
Structural alerts – certain functional groups that have been linked to increased toxicity due to their metabolites.
104
What are cofactors?
Non-protein component required to allow an enzyme to perform its role.
Bind within enzyme to promote enzymatic processes.
Inorganic Cofactor Ions – Mg, Zn, Cu, Fe, Mn, Ni, Mb
Organic Cofactors (Coenzymes) – typically derived from vitamins
105
What are the two forms of metabolism that the body does to drugs?
Redox and hydrolase
