Carbohydrates

Energy + structure molecules OH H HO CH2OH O Carbohydrates Energy + structure molecules

Outline Structure Monosaccharides Disaccharides Polysaccharides Hexose sugars Pentose sugars Disaccharides Polysaccharides branching

Carbohydrates are composed of C, H, O (CH2O)x C6H12O6 (CH2O)x C6H12O6 sugar sugar sugar sugar sugar sugar sugar carb = carbon hydr = hydrogen ate = oxygen compound monosaccharide polysaccharide disaccharide

Sugars = FAST energy 6 5 3 Most names for sugars end in -ose Classified by number of carbons 6C = hexose (glucose) 5C = pentose (ribose) 3C = triose (glyceraldehyde) Glyceraldehyde H OH O C OH H HO CH2OH O Glucose H OH HO O Ribose CH2OH 6 5 3

Sugar structure 5C & 6C sugars form rings in solution Why a ring? To make it stable! Carbons are numbered

C C O C C C C Numbered carbons These will become important in DNA! 6' C O 5' C C 4' 1' energy stored in C-C bonds harvested in cellular respiration C C 3' 2'

Functional Group Review hydroxyl WHY can glucose dissolve in water?

Simple vs. Complex Sugars Monosaccharides Disaccharides Polysaccharides ENERGY STORAGE & STRUCTURE OH H HO CH2OH O FAST ENERGY

MONOsaccharides Glucose, Miss Monosaccharide PENTOSE SUGARS How many sugars? MONOsaccharides Glucose, Miss Monosaccharide PENTOSE SUGARS HEXOSE SUGARS Hommie #1: Fructose Hommie #2: Galactose Isomers = Same chemical formula (C6H12O6) but different arrangements

DIsaccharides Formed by dehydration synthesis How many sugars? DIsaccharides Formed by dehydration synthesis Glycosidic linkage is formed 3 major disaccharides:

Maltose – used in beer brewing Dehydration synthesis monosaccharides disaccharide H2O maltose | glucose | glucose | maltose glycosidic linkage

Sucrose – table sugar Dehydration synthesis monosaccharides disaccharide H2O | glucose | fructose | sucrose (table sugar) sucrose = table sugar

Lactose – sugar found in milk Dehydration synthesis between glucose + galactose Lactose-intolerance For lactose intolerance: Lactaid pills – laced with the enzyme that aids in dehydration synthesis Lactaid milk – lactose is already separated into simple monomers Instead of taking AWAY water, we should…

Making and Breaking Biomolecules dehydration synthesis (synthesis) = polymerization hydrolysis (digestion) = depolymerization

POLYsaccharides Polymers of sugars Function: How many sugars? POLYsaccharides Polymers of sugars costs little energy to build easily reversible = release energy Function: energy storage structure Polysaccharides are polymers of hundreds to thousands of monosaccharides

Digestion = Energy Release Linear polysaccharide Which polysaccharide releases energy the fastest? Enzymes aid in the digestion of polysaccharides into monosaccharides Branched polysaccharides (like glycogen) allow for faster digestion and therefore faster energy release Faster digestion! = Faster energy release! Branched polysaccharide

Polysaccharides – Energy Storage Starch Glycogen Usually linear Slow energy release In plants! Usually branched Fast energy release In animals (liver, muscles)

Polysaccahrides as Structural Molecules Cellulose Chitin Cellulose – plant cell walls Chitin – fungi and arthropods Peptidoglycan - bacteria Peptidoglycan

Let’s talk about digestion. We eat a lot of carbohydrates… cellulose starch glucose

Digesting starch vs. cellulose enzyme starch easy to digest cellulose hard to digest Starch = all the glycosidic linkage are on same side = molecule lies flat Cellulose = cross linking between OH (H bonds) = rigid structure enzyme only bacteria can digest

Ways to Digest Cellulose How can herbivores digest cellulose so well? BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals Humans can’t digest cellulose… so we poop it out. I should have eaten my fiber!