Exam 2: Macromolecules: Carbohydrates Flashcards
characteristics of macromolecules
- building blocks of living organisms
- polymers of individual subunits/monomers
- all contain carbon and hydrogen, most oxygen
- C-C bonding forms rings or chains that functional groups can attach to
- functional groups affect structure and function
Carbon functions
- forms 4 bonds for stability
- able to bind other carbons
- forms complex structures such as rings and chains
- able to form single as well as multiple bonds
- HAVE CHIRALITY
what does chirality mean?
a carbon with 4 different bonds
what are stereoisomers?
4 unique groups arranged in different ways
- same formula, dif 3D shape
D (R) isomers rotate light how?
clockwise
L (S) isomers rotate light how?
counterclockwise
Which form do racemic mixtures have
both D and S
Why is stereochemistry important in pharmecuticals?
- stereoisomers have same chemical formula and attachments, but differ in spatial arrangements
- effects binding ability and affinity
- binding poorly to the target effects the efficacy
- binding a site other than the target site can be disastrous
History of thalidomide in US
- Taussing : treated these people
- Kelsey: FDA, refused to do this, both said no
not a lot of cases in US. many elsewhere
Thalidomide
developed to treat nausea
- R version is sedative, calms people down
one form effective and the other not
- R worked well in pregnant women
- S is a terotegen:
causes defects in unborn in development of arms and legs receptors
4 main categories of macromolecules
carbohydrates, lipids, proteins, nucleic acids
Carbohydrate functions
- energy, storage, structure
- cell recognition and communication
- modifies proteins effecting
- structure/folding, enzyme kinetics,
turnover/degradation
Structure of carbohydrates
monomer: CH2O
carbohydrate terminology
ose: refers to sugars
mono, di, poly refers to degree of polymerization
Two examples of simple sugars
glucose and fructose
what is the difference between glucose and fructose?
glucose is an aldose sugar (carbonyl on end)
fructose is a ketose sugar (carbonyl in middle)
similarities between glucose and fructose
both D-isomers, right handed
we only use Right form
If many chiral carbons how do we know what form it is in?
highest chiral carbon, look at the OH group
- if written on the right it is right handed
What if bacteria could make left handed form in protective capsule?
it is better for them, they get added defense that we cannot break down
What if you ate breakfast and all sugars were left handed?
enzymes would not fit into the active site
transporters could not bind to get it out so it would stay in the gut
- attracts water to it since hydrophilic so you get diarrhea
alpha form of carbohydrates
opposite sides
OH in the down position
beta form of carbohydrates
same side
OH in up form
anomeric C
one with carbonyl
forms the ring
Binding to find Di/Polysaccharides
condensation, dehydration rxn to remove water (OH from one, H from other) and combine sugars
