Digestion What we eat Page 400-404

Nutrients To stay healthy, we need: Carbohydrates Proteins Lipids Water Vitamins Minerals We need each one of these for our bodies to work properly

Carbohydrates Also called saccharides Main source of energy for us as well as most other organisms Made up of carbon, hydrogen and oxygen

Carbohydrates Monosaccharides: simple sugars A molecule made up of one ring structure Glucose Fructose

Carbohydrates Monosaccharides: simple sugars These are the small molecules that all our cells use for energy

Carbohydrates Disaccharides Two monosaccharides put together Lactose Sucrose

Carbohydrates Polysaccharides: complex carbohydrates Made up of long chains of monosaccharides Can be straight or branched Cellulose Starch

Carbohydrates Polysaccharides: complex carbohydrates Glycogen Polysaccharide found in animals We store excess glucose as glycogen for use later

Proteins Some are major structural component to our bodies Others are enzymes that perform all the chemical reactions that occur during metabolism

Proteins Made up of subunits called amino acids Amino Carboxyl group group Variable group

Proteins Made up of subunits called amino acids There are 20 different amino acids

Proteins Made up of subunits called amino acids There are 20 different amino acids Our body can make 12 of them The other 8 we must obtain from our food Called the essential amino acids

Lipids Major source of energy for our bodies It is also a major structural component All cellular membranes are mainly lipids

Lipids Triglyceride: one type of lipid Made up of a glycerol molecule bound to 3 fatty acids Glycerol Fatty Acids

Lipids Triglycerides: Can be either saturated or unsaturated Saturated: usually solid (fats) at room temperature Butter and animal fat Unsaturated: usually liquid (oils) at room temperature Plant and fish oils

Lipids Essential fatty acids Ones that our bodies need but cannot produce Omega-3 and Omega-6 Unsaturated Found in oily fish and some nuts, seeds and leafy vegetables

Vitamins Small molecules that are needed to support an organism’s basic functions Most we obtain from our diet A few we can actually produce

Vitamins Vitamin D: produced by skin cells that are subjected to the sun’s light Vitamin K: produced by bacteria in our large intestine Vitamin A: produced using beta-carotene, a molecule found in carrots, eggs, and green vegetables

Minerals Naturally occurring elements needed by our bodies Fe: for hemoglobin to carry oxygen Ca and P: for bones Na and K: for nerve signals Some are needed in very small amounts Zn, Cu, Fl

Homework Read “Healthy Eating” on pages 403-405 Answer question 2 on page 405 Instead of recording your food for one day, record it for this weekend