Organic Chemistry 1 Flashcards
Water is:
Highly cohesive (high affinity for one another)and polar.
Electronegativity:
The measure of the force of an atom’s attraction for the electron it shares in a chemical bond with another atom.
Electronegativity in the periodic table
From left to right: increasing +ive charges in the nucleus Bottom to top: decrease in the distance of valence electrons from the nucleus
Non-polar bonds:
< 0.5
Polar bonds
0.5 - 1.9
Ionic bonds
> 1.9
ACID
proton donor, produces H3O+ ions in aqueous solutions.
BASE
proton acceptor, produces OH- ions in aqueous solutions.
pH
-log[H3O+]
The LARGER the pKa (small Ka)
the WEAKER the acid
The SMALLER the pK (large Ka)
the STRONGER the acid
LARGE pKb
STRONG base
SMALL pKb
WEAK base
When a base accepts a proton
it is converted to its conjugate acid
When an acid transfers a proton
it is converted to its conjugate base
Buffer solution
weak acid and conjugate base to resist changes in pH
Functional groups
- reactive parts of organic molecules - essential for life - same functional groups on compounds allows similar reactivity
Alkane
CnH2n+2 chair conformation most stable
Alkene
CnH2n
TRANS
OPPOSITE
CIS
SAME
Nomenclature
meth- eth- prop- but- pent- hex- …
Priority
higher atomic number determines priority
Alkyl
Alkane - H
Alcohol -ol
Hydrogen bonds are weaker than covalent but have a significant effect on properties: - Higher bp than alkanes - more soluble in water both due to (-OH)
Amines
1°, 2°, 3° depending on how many H’s have been replaced. -polar - weak bases, aqueous solutions are basic - aliphatic amines ~pKb 3-4
Aliphatic
A class of saturated or unsaturated carbon compounds, in which the carbon atoms are joined in open chains.
Aldehydes -al
H-C=O Methanal: 2H’s Everything else: 1H & 1C
Ketones -one
2C-C=O
Aldehyde & Ketone properties
- higher bp - more soluble in H2O than nonpolar compounds of comparable size
Carboxylic Acids -CO2H
- high bp, very strong intermolecular hydrogen bonds - solubility decreases and hydrophobic tail increases - resonance increases acidity
Isomer:
different compounds with the same molecular formula
Constitutional isomer:
isomer with different connectivity
Stereoisomer:
same molecular formula, same connectivity but different orientation so that cannot be interconverted by rotation about a single bond. (different atomic arrangement in space)
Enantiomers:
mirror images, non-superimposable.
Diastereomers:
non-mirror images.
Chiral:
non-superimposable on their mirror image.
Achiral:
are superimposable on mirror image.
Stereocentre:
Carbon with 4 different groups bonded to it. 2 stereocentres = 2^2 Therefore, 4 stereoisomers.
Oxidation:
REMOVAL of electrons or H from an atom and/or ADDITION of O
Reduction:
ADDITION of electrons or H to an atom or REMOVAL of O
ATP, ADP, AMP
universal carriers of phosphate groups, energy source
ATP:
Hydrolysis of terminal phosphate of ATP gives ADP + phosphate + energy
NAD/NADH FADH/FADH2
coenzymes involved in oxidation/reduction of metabolic intermediates
NAD+
an important coenzyme found in cells. It plays key roles as carriers of electrons in the transfer of reduction potential.
NADH
reduced form of NAD+
FADH/FADH2
FADH and FADH2 are reduced forms of FAD. FADH2 is produced in the citric acid cycle.
β-oxidation
process by which FA, in the form of Acel-CoA, are broken down to form Acetyl-CoA, the entry molecule for the CAC.
β-oxidation [1]
oxidation of C-C to C=C by FAD
β-oxidation [2]
hydration of C=C, R enantiomer formed
β-oxidation [3]
oxidation of β-hydroxyl group to a carbonyl group by NAD+
β-oxidation [4]
cleavage of C chain by a reverse Claisen condensation (thiolysis)
Carbohydrates
- Natural monosaccharides are sweet - Highly soluble MONOS due to the extensive hydrogen bonding between OH groups - tri(number of C)ose(carbohydrate), tetrose, pentose
L -
OH LEFT
D +
OH RIGHT
Haworth projections
Anomeric carbon is the new stereocentre that is formed
OH RIGHT
F: down Haworth: α
OH LEFT
F: up Haworth: β
Mutarotation:
is the change in the rotation between two anomers, α & β.
Mattose (di)
α-1,4 - glucosidic bonds
Sucrose (di)
α- 1, 2 - glucosidic bonds
Unbranched polys
1,4 α glucosidic bonds
Branched polys
1,4 α glucosidic bonds & 1,6 α glucosidic bonds
Starch
1,4 α glucosidic bonds & 1,6 α glucosidic bonds
Cellulose
1,4 β glucosidic bonds
Lipids
-insolubility in H2O due to large hydrocarbon component - saturated: solid/semi-solid - unsaturated: liquid - storage of energy - made of glycerol + 3 FAs
Saturated lipids
DECREASE mp as C increases
Unsaturated lipids
INCREASE mp as C decreases & C=C decrease
Micelle:
spherical arrangement of lipids in water so that hydrophilic head points out, hydrophobic in.
Waxes:
are esters formed from long chains of carboxylic acids and alcohols.
Phospholipids:
Glycerol + 2FA + phosphoric acid
Saponification:
The reaction of an ester with a metallic base and water.
Fatty Acids
usually C12-20, unbranched, C-C, C=C (must be cis)
Amino acids
Side chains determine their behaviour in water,