general knowledge Flashcards
amylose
starch. a glucose, linear structure, rarely branches
C 1-4 glycosidic bonds
amylopectin
starch. a glucose, highly branched (every ~24-30 units)
C 1-4 glycosidic bonds and C 1-6 for branching units
cellulose
b glucose, unbranched, linear structure
glycogen
a glucose, most branched (every ~8-12 units)
glycosidic bond
bond between monosaccharides R-C-O-C-R’
peptide bond
bonds between amino acids CONH
empirical formula of monosaccharides
CH2O
diff between a-glucose and b-glucose
rotation of carbon 1
a: hydroxyl below
b: hydroxyl above
how to make a buffer solution
weak acid with a base as the limiting reagent
when does an indicator change colour
when Pka = pH i.e. [HIn]=[In-]
what are the properties of an ideal standard solution for titrations
needs: stable, high purity substance, highly soluble, high molar mass, known chemical formula, doesnt react with atmosphere
more negative reduction potential means…
substance will be oxidised, acts as anode
difference between cis and trans isomerism
cis: same side
trans: opposite side (cos they swap genders)
(both geometric isomers)
a helix vs b pleated sheets
helix - H bonding within chains (intrachain)
pleated sheets - H bonding between chains (interchain)
helix - flexible
sheets - rigid, strong
saponification
triglyceride + NaOH. glycerol broken off triglyceride and Na attached, condensation reaction.
how do micelles work
soap has: hydrophobic tail (Carbon chain), hydrophilic head (COONa)
tails of soaps attracted to oil while head attracted to water, soaps align and cluster together forming a circular micelle which traps oils.
why doesnt soap work in hard water
because Ca and Mg have a greater ionic charge (2+) than Na (1+), Na is taken off soap and replaced with Ca or Mg. this forms non-polar insoluble salts.
how to tell between aldehyde and ketone using mass spectroscopy
if peak at m/z 29 -> COH therefore aldehyde
how does gel electrophoresis work
separates molecules based on polarity, more polar molecules move further across gel.
atom economy
(molar mass of desired product)/
(total molar mass of reactants)
difference between LDPE and HDPE
LDPE: highly branched -> lower BP/MP
HDPE: minimally branched -> higher BP/MP
syntactic vs atactic vs isotactic
alternating (sine wave) vs random vs same side
henderson hasselbach equation
pH=Pka + log ([A-]/[HA])
difference between spontaneous and non spontaneous redox reactions
spontaneous occurs in galvanic cell. cell potential is positive
non-spontaneous occurs in electrolytic cell. cell potential is negative.
