BIO1140 Chapter 3b - The Macromolecules of the Cell (part 2)

BIO1140 Chapter 3b - The Macromolecules of the Cell (part...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
CARBOHYDRATES The monomers are Monosaccharides Polysaccharides are long-chain polymers of sugars and sugar derivatives Consists of a single monomer – monosaccharides Can be an aldehyde (1 hydroxyl group) or a ketone (2 or more hydroxyl groups) o Aldosugars – terminal carbonyl group o Ketosugars – internal carbonyl group Can also be classified by the number of carbons which they have o 3 - triose o 4 - tetrose o 5 - pentose o 6 - hexose o 7 - heptose Most common monosaccharide is an aldohexose – d-glucose o It has 4 asymmetric carbons o Therefore have 16 possible stereoisomers (d-glucose is the most stable) Formula for carbohydrates: C n H 2n O n Put pic in on page 61 See note on page 62 about Haworth projection Disaccharides – consists of two monosaccharide units linked covalently Three common disaccharides are: o Maltose --- alpha D-glucose + alpha D-glucose Alpha glycosidic bond o Lactose --- beta D-glucose + beta D-galactose Beta glycosidic bond o Sucrose --- alpha D-glucose + beta D-fructose Alpha glycosidic bond Alpha – down Beta – up (b’s – up) PUT IN PIC ON PG 62 OF COMMON DISACCHARIDES
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
They are all formed by a condensation reaction which results in a glycosidic bond o Bonds can be alpha or beta depending on the configuration of the hydroxyl group of the first carbon atom Polymers are Storage and Structural Polysaccharides Polysaccharides have either a storage or structural function Storage – starch in plants; glycogen in animals Glycogen: o Consist of alpha D-glucose units and alpha glycosidic bonds o There may be alpha bonds that link carbons 1 to 4 of adjacent glucose units o These polysaccharides may contain an occasional alpha linkage (between carbons 1 – 6) along the backbone -- DON’T UNDERSTAND Can be branched depending on presence of these alpha linkage Ex. Glycogen is highly branched because there is an alpha linkage occurring every 8 to 10 glucose units along the backbone. This causes short side chains (8- 12 units long). It is stored in the liver as a source of glucose to maintain blood sugar levels or a fuel source to generate ATP for muscle contraction Starch: o Unbranched – amylose o Branched – amylopectin It as alpha branches (between
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

BIO1140 Chapter 3b - The Macromolecules of the Cell (part...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online