Ochem review Flashcards
What macromolecules are most prominent in the human body?
Water
Protein
Lipids
Nucleic Acid
What functional groups make up amino acids?
amino and carboxylate groups
What makes up lipids?
3 fatty acids linked to glycerol via ester bonds
what makes up proteins?
amino acids linked by amide (peptide) bonds
what is the difference between carboxylic acid and carboxylate groups?
Carboxylic acids contain a hydrogen that carboxylate groups do not
saturated and unsaturated
Saturated fats contain no double bonds and unsaturated contain double bonds
Aerobic glycolysis
Lactate (hydroxy group) is converted to pyruvate (keto group) via lactate dehydrogenase enzymes
Anaerobic glycolysis
Pyruvate (Keto group) is converted to lactate (hydroxyl group).
Condensation reactions
- condenses two molecules into one creating a new functional group
- requires energy and holds energy
- produces water
Anhydrides
condensation between 2 acid groups creating a high energy bond
organic anhydride
two carboxyllic acids
mixed anhydride
one carboxyllic acid and one phosphoric acid
phospho-anhydride
two phosphoric acids (energy storage)
ATP components
phosphoanhydride bonds
phosphomonoester bond
glycosidic bond
alcohol groups
Acids
- electron pair acceptor
- has a hydrogen proton associated with it
Bases
- electron pair donating
- usually a charge, but not always (ammonia)
Covalent bonds
sharing electrons between two atoms complete on their outer shell
Non-polar covalent
electrons are shared almost equally
polar covalent bonds
the electron cloud is more dense around one atom so the electrons are not shared equally
electronegativity
the relative affinity an atom has for an electron (Nitrogen and Oxygen are more electronegative than Carbon and therefore have a partial negative charge when bonded)
Hydrogen Bonds
Weak interactions that are easily formed and easily broken due to partial charges in interactions
- examples
- base pairing in DNA (AT weaker and lower melting point)
- enzyme-substrate interactions
Hydrophillic Molecules
- soluble in water
- requires formation of charge based interactions
Hydrophobic Molecules
-insoluble in water
Solubility rule of thumb
C:(O+N) ratio
if 4:1 or less, soluble
if 7:1 or more, insoluble
Amphipathic molecules
distinct hydrophobic and hydrophilic regions
- example
- fatty acid chain has hydrophobic tail and hydrophilic head
micelles
lipid bilayer
Phosphate transfer
A phosphate group (from ATP) is transferred to another molecule to create a phosphomonoester bond
-catalyzed by Kinases
Phosphate Cleavage
the phosphate is removed from a compound when the phospohmonoester bind is hydrolyzed
-catalyzed by phosphatases
Rearrangement Reactions
bonding pattern undergoes rearrangement but the overall molecular formula stays the same
-Structural isomers
Condersation-Hydrolysis Reactions
the condensation of 2 molecules forming a single molecule with a byproduct of water
-require ATP
Hydrolysis Reactions
the disassembly of polymers to their monomeric units
-requires water, not energy
Oxidation reactions
loss of H-atoms and gain of O atoms
-use dehydrogenases
Reduction Reactions
gain of H atoms and loss of O atoms
-use oxidases/ reductases
Dehydrogenase
enzyme that removes 2 hydrogen atoms from a substrate
Oxidases
Enzyme that add 1 oxygen atom to a substrate
Reductases
Enzyme that adds 2 Hydrogen atoms to a substrate
Acid-Base reactions
An acid is a proton donor and a base is a proton acceptor
pH
-log[H+]
Strong Acids
completely dissociate
-no PKA
Weak Acids
dissociate to a limited extent
-has pka
Ka
Ka= [base][H+]/[Acid]
pKa=-log[Ka]
the lower the pKa, the stronger the acid
Henderson-Hasselbach Equation
pH=pKa + log [Conjugate Base]/[Acid]
Buffers
a weak acid and its conjugate base.
two factors: the buffers pH range (within 1 pH units) and the buffers concentration (buffering capacity)
-when pH of solution=pKa, conjucate base=acid
-when pH>pKa, conjugate base > acid
-when pH
Absorption of charged molecules
Charged molecules are not absorbed
Non charged molecules are absorbed
pKa ranges for carboxylic acids and amino groups
Carboxylic acid= 2-7 ( acid uncharged, conjugate base charged)
Amino groups= 6-10 (acid charged, conjugate base uncharged)
If pH = pKa, is the drug absorbed?
50% of the drug is absorbed because half of it is charged and cannot be absorbed, and the other half is uncharged and can be absorbed
