Carbohydrates

OH H HO CH2OH O Carbohydrates: Energy molecules

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?

Lipids: Fats & Oils 2003-2004

Concentrated energy molecules Lipids Concentrated energy molecules

Lipids Examples fats oils waxes hormones sex hormones testosterone (male) estrogen (female) 2003-2004

Lipids Function: energy storage cell membrane cushions organs very concentrated twice the energy as carbohydrates! cell membrane cushions organs insulates body think whale blubber! 2003-2004

Structure of Fat not a chain (polymer) = just a “big fat molecule”

Saturated fats Most animal fats Limit the amount in your diet solid at room temperature Limit the amount in your diet contributes to heart disease deposits in arteries

Unsaturated fats Plant, vegetable & fish fats liquid at room temperature the fat molecules don’t stack tightly together Better choice in your diet

Saturated vs. unsaturated  2003-2004

Other lipids in biology Cholesterol good molecule in cell membranes make hormones from it including sex hormones but too much cholesterol in blood may lead to heart disease 2003-2004

Other lipids in biology Cell membranes are made out of lipids phospholipids heads are on the outside touching water “like” water tails are on inside away from water “scared” of water forms a barrier between the cell & the outside 2003-2004

Let’s build some Lipids!