Emily Marshall
David Geiger
Kreigh Kamman
Stephanie Bradburn
Caroline Peterson
Carbohydrates
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Functions
o Energy storage (starch, glycogen)
o Structural (cellulose, chitin)
o Signaling (informational, localization)
o Protective (bacterial cell walls)
Polyhydroxy aldehydes or ketones
o Mostly made up C:H:O= 1:2:1
o Can have N, P, S
Forms
o Monosaccharides
 Simple sugars
 D-glucose is most abundant
• Look at chiral center. If OH on chiral center furthest from
carbonyl is on the right in a fisher projection then it is D, if
on left then L.
 Unbranched C-chain with single bonds between C’s.
 One C double bonded to O
 All other C’s have OHs
 C=O can be aldehyde or ketone
 Fisher projection
• Flat representation, numbering starts at carbonyl
 Epimer- one chiral center
 If you have n chiral centers then you have 2n chiral centers
 Anomers
• α OH on anomeric carbon is on opposite side of plane on
bulky group from furthest chiral center
• β OH on same side
 Recognize chair structures
• Equatorial
• Axial
• Bulky groups more stable if equatorial
o Disaccharides
 Two monosaccharides connected through a glycosidic bondcondensation of anomeric carbon and an alcohol
 Know how to form the ring from the fisher projection- Practice
drawing the connection between two monosaccharides
 Reducing sugar can open back up from its ring structure to the
carbonyl
 Non-reducing sugar cannot reopen or be part of a glycosidic bond
o Polysaccharides
Emily Marshall
David Geiger
Kreigh Kamman
Stephanie Bradburn
Caroline Peterson
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Homopolysaccs repeating unit of the same sugar
• Two function:
o Structural- cellulose (plants), Chitin (animals)
 Cellulose has maximal H-bonds to self, very
strong, water insoluble. Β 1 4 glucose
 Chitin is Β 1 4 N-acetyl-D-glucosamine,
Β link is non-digestible
• Β 1 4 is much more elongated and
H-bonds to self
o Energy storage- starch, glycogen
 Need α bonds so that we can digest them
• Starch- amylose α 1 4 glucose and
amylopectin which has the 1  6
glucose
• Enzymes that break glucose by
breaking glycosidic bonds start at the
non-reducing end. The branching
breaks the 1  6. Can only release
every single glucose if you have the
branching enzymes.
• Glycogen α 1 4 & α 1  6
 Energy storages ones exist to compact it
Heteropolysaccsrepeating unit is a disacc
• Peptidoglycan layer- bacteria
• Extracellular matrix of mammalian cells
o Sugars-highly negatively charged so they all want
to stay away from each other
• See proteoglycan worksheet
o Proteoglycans are protein plus glycosaminoglycans
 Mostly made up of polysaccharides
o Glycoproteins
 Mostly amino acids
 Proteins plus glycosylated
• Functions of protein modification
o Structure
o Recognition Events
o Target new protein
o Clearing protein from blood
by liver
o Control cell growth
o Fertilization
o Viruses, bacteria and euk
parasites
• Types
Emily Marshall
David Geiger
Kreigh Kamman
Stephanie Bradburn
Caroline Peterson
o N-linked
 Co-translational
 Beta link of N of
amino acid and most
of the time Asn.
o O-linked
 Post-translational
 Takes place in the
Golgi
 Structure specific
 OH of the serine of
threonine
o Oligosaccharides
 Small group of sugars
Lipids
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Molecules of biological origin that are water insoluble, soluble in organics
(phenol)
o Functions
 Structural
 Energy storage
 Signaling
 Vitamins and hormones
o Fatty acid- hydrocarbon chain plus carboxylic acid
 Saturated- with maximum number of Hs, no double bonds
• Ex: animal fats
• Most likely to be solid at room temp, packed together most
tightly, lots of van der waals, higher melting point
 Unsaturated- at least one double bond
• Ex: plant oils
• Packs together the least well, fewest van der waal
interactions, lowest melting point, likely to be a liquid at
room temperature
• Cis puts large kink into chain
• Trans is non-biological from hydrogenation of plant oils
 Know nomenclature- Delta, Omega
 Cis is biologically relevant
o Triacylglycerols
 True fats, triglycerides, glycerol backbone esterified with three
fatty acids
• Know structure
Emily Marshall
David Geiger
Kreigh Kamman
Stephanie Bradburn
Caroline Peterson
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Simple triacylglycerol- R1=R2=R3
Non-polar overall
Preferred energy storage molecules
o More reduced
o Less associated H2O
Know phospholipid and sphingolipid structure
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o Cholesterol
 Membrane associated lipid, rigid, recognize structurally similar to
steroids
o Vitamins
 Fat soluble and Water soluble
o Membranes
 Composed of lipids, proteins, and carbs
 Proteins associated with membranes
• Peripheral
o Removed through salting
• Integral
o Removed with detergents
• Lipid- modified
o Removed enzymatically
o Aggregation
 Micelle
 Bilayer
 Vesicle
• Useful for getting things across membrane