Carbohydrates Carbohydrates Molecules containing carbon hydrogen and oxygen
Carbohydrates
Carbohydrates Molecules containing carbon, hydrogen and oxygen General formula is CH 2 O hence carbo-hydrate Mainly used in living organisms as a source of energy Plants produce carbohydrates in photosynthesis
Monosaccharides (simple Sugars) Sugars that contain only one subunit Most important for biology contain 6 carbon atoms in a ring structure with hydroxyl groups Primary energy storage is Glucose (C 6 H 12 O 6) its structure is below
Monosaccharides continued… The two other biologically important sugars are fructose and galactose These two sugars have the same formula as glucose (C 6 H 12 O 6) but are structurally different and are thus called ISOMERS
Monosaccharides Continued…. . a, b Glucose and galactose have the same formula and the same structure however they differ in the side of carbon the hydroxyl groups are placed thus they are called STEREOISOMERS Stereoisomers: are isomers that have the same molecular formula and sequence of bonded atoms but differ in the three- dimensional orientations of their atoms in space.
Disaccharides Two monosaccharides bound together to make a disaccharide (double sugar) The bonding takes place between a hydroxyl group of each monosaccharide When the two molecules are joined a hydrogen is lost from a hydroxyl of one sugar and the other sugar loses the entire OH group. H + OH makes water thus this process is called DEHYDRATION SYNTHESIS
Glycoside Bond Glycosidic Linkage
Polysaccharide (Complex Carbohydrates) Long chains made by linking many monosaccharides together
Polysaccharides (STARCH) Plants store chemical energy in the form of starch It is composed of two polysaccharides 1) Amylose 2) Amylopectin
Starch continued…… Both are polymers of alpha glucose Amylose contains a 1 -4 glycocidic likage Amylopectin contains a branch bonding to amylose chains forming a 1 -6 glycocidic linkage Animals do not use starch as a fuel source directly but instead break it down via digestion into its usable form: GLUCOSE
Glycogen Highly branched polysaccharide made of alpha glucose Used by ANIMALS to store chemical energy
Cellulose Primary component of plant cells Made up of glucose however it is a long chain of beta glucose This difference makes it indigestible to humans Important in diet as it “keeps us regular”
Chitin Primary component of the hard exterior of insects and crustaceans Structure is a modified form of cellulose Hard for humans to digest Used in soluble stiches and contact lenses
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