CARBOHYDRATES L3 Biology

Make the above structures (hydroxyl group on Carbon) Perform Dehydration Synthesis!

FACTS ABOUT CARBOHYDRATES Includes sugars, starches, cellulose, glycogen Made up of carbon (C), hydrogen (H), and oxygen (O) The ratio of hydrogen to oxygen is always 2:1 (like water) Provide ENERGY!

Carb facts, cont. Simple sugars = monosaccharides and disaccharides Complex sugars= polysaccharides The chemical names of sugars end in -ose

Simple SUGARS Monosaccharides or disaccharides They taste sweet! EXAMPLE: glucose The chemical formula for glucose is C 6 H 12 O 6 The structural formula for glucose is

GLUCOSE C 6 H 12 O 6

SUGARS (cont.) ANOTHER EXAMPLE: galactose The chemical formula for galactose is C 6 H 12 O 6 The structural formula for galactose is

GALACTOSE

SUGARS (cont.) ANOTHER EXAMPLE: fructose The chemical formula for fructose is C 6 H 12 O 6 The structural formula for fructose is

FRUCTOSE

Compare & Contrast!

GLUCOSE, FRUCTOSE & GALACTOSE ALL HAVE THE SAME FORMULA - C 6 H 12 O 6 What are molecules that have the SAME MOLECULAR FORMULA BUT DIFFERENT STRUCTURAL FORMULAS called? ISOMERS!

How are disaccharides and polysaccharides made? DEHYDRATION SYNTHESIS!! It occurs when enzymes (catalysts) chemically combine small molecules (i.e., monomers) to make a large molecule (i.e., polymer)

DEHYDRATION SYNTHESIS (monomers polymer) This is a reaction that occurs between two monosaccharides to make a di- or polysaccharide EXAMPLE: glucose + fructose sucrose (table sugar) + water The result of dehydration synthesis is a larger molecule + water

Dehydration Synthesis, cont. Animation: 4t/bio20/mm/m7/hydrolysis/Bio2 0_Hydrolysis_Final.swf

POLYSACCHARIDES A very large molecule formed by joining MANY monosaccharides together using dehydration synthesis reactions A biological polymer Polysaccharides taste different from monosaccharides!

3.7 Polysaccharides: Long chains of sugar monomers Starch is a storage polysaccharide composed of glucose monomers and found in plants (bread, potatoes) Glycogen is a storage polysaccharide composed of glucose, which is hydrolyzed by animals (us!!) when glucose is needed for ENERGY!! Copyright © 2009 Pearson Education, Inc.

3.7 Polysaccharides, cont. Cellulose is a polymer of glucose that forms plant cell walls; Can we digest it? Chitin is a polysaccharide used by insects and crustaceans to build an exoskeleton

Starch granules in potato tuber cells Glycogen granules in muscle tissue Cellulose fibrils in a plant cell wall Cellulose molecules Glucose monomer GLYCOGEN CELLULOSE Hydrogen bonds STARCH

GLYCOGEN-short term energy storage in the body

HYDROLYSIS: (polymer monomer) Polysaccharides are broken down into smaller molecules (monosaccharides) by enzymes Enzyme (a catalyst for the rxn) adds water to the molecules at the bond. A monomer is formed, and the polymer is shortened by 1 molecule.

Hydrolysis, cont. EXAMPLE: Amylase= enzyme in saliva amylase ( adds H 2 0 to bond ) polysaccharides monosaccharide (starchy taste) (sweet taste)

Animations! /mm/m7/hydrolysis/Bio20_Hydrolysis_Fin al.swf /student_view0/chapter25/ani mation__enzyme_action_and_the_hydroly sis_of_sucrose.html

Dehydration Synthesis & Hydrolysis Dehydration Synthesis: a reaction that occurs between two “biomonomers” to make a biopolymer (hint… remove a water between the two monomers to join them…) Hydrolysis: a reaction that adds water to a biopolymer to break it into smaller molecules (hint…add 2 H’s and an O to restore your two glucose molecules)