Carbohydrates

OH H HO CH2OH O Carbohydrates: Energy molecules 2009-2010

sugar - sugar - sugar - sugar - sugar Carbohydrates Building block molecules = sugars sugar - sugar - sugar - sugar - sugar sugar

Carbohydrates Function: Examples quick energy energy storage structure cell wall in plants Examples sugars starches cellulose (cell wall) glucose C6H12O6 sucrose starch

Sugars = building blocks Names for sugars usually end in glucose fructose sucrose maltose -ose OH H HO CH2OH O glucose C6H12O6 fructose maltose sucrose

Building carbohydrates Synthesis 1 sugar = monosaccharide 2 sugars = disaccharide | glucose | glucose | maltose mono = one saccharide = sugar di = two

Building carbohydrates Synthesis 1 sugar = monosaccharide 2 sugars = disaccharide | glucose | fructose | sucrose (table sugar) How sweet it is!

BIG carbohydrates Polysaccharides large carbohydrates starch glycogen energy storage in plants potatoes glycogen energy storage in animals in liver & muscles cellulose structure in plants cell walls chitin structure in arthropods & fungi exoskeleton poly = many

Building BIG carbohydrates glucose + glucose + glucose… = polysaccharide starch (plant) energy storage glycogen (animal)

Digesting starch vs. cellulose enzyme starch easy to digest Animals do not have the enzyme to digest cellulose. We need the help of bacteria living in our intestines. enzyme cellulose hard to digest

Cellulose Cell walls in plants herbivores can digest cellulose well most carnivores cannot digest cellulose that’s why they eat meat to get their energy & nutrients cellulose = roughage stays undigested keeps material moving in your intestines Cross-linking between polysaccharide chains = rigid & hard to digest The digestion of cellulose governs the life strategy of herbivores. Either you do it really well and you’re a cow or an elephant or a horse (spend a long time digesting a lot of food with a little help from some microbes & have to walk around slowly for a long time carrying a lot of food in your stomach) Or you do it inefficiently and have to supplement your diet with simple sugars, like fruit and nectar, and you’re a gorilla.

Different Diets of Herbivores Cow can digest cellulose well; no need to eat other sugars Gorilla can’t digest cellulose well; must add another sugar source, like fruit to diet

Helpful bacteria How can cows digest cellulose so well? BACTERIA live in their stomachs & help digest cellulose-rich (grass) meals Eeeew… Chewing cud?

Let’s build some Carbohydrates! EAT X Let’s build some Carbohydrates! 2009-2010

Activities building starch by bonding together paper glucose molecules eat carrots, celery, cookies