 Make up ~10% of daily calories  Are not a primary energy source › Carbohydrates and fats are!  Important in maintaining and replacing body tissues (growth)  Found in almost every living cell and liquid › Blood (clotting) › Muscles, organs › Used to make hemoglobin

 Enzymes are proteins!  Accelerate the rate of metabolic reactions › Ex. food digestion  Highly selective catalysts › Increase the rate of reaction, not a reactant

 Amino acids (aa’s) are the building blocks of proteins (monomers)  20 different amino acids make up >20,000 proteins in the body Amine group Carboxylic acid Functional group

Amino Acid 1Amino Acid 2

 Chains of amino acids  Multiple polypeptides join together to form a functional protein

 Meat: Beef, poultry, pork and lamb  Fish and shellfish  Dairy products: cottage cheese, cheese, yogurt, and milk  Egg whites, and egg substitutes  Dry beans, peas, oats and legumes  Tofu and soy products  Nuts and seeds

 Our bodies can synthesize 12 out of 20 of the amino acids  We need to get the other 8 amino acids from our food › They are called essential amino acids

Complete ProteinsIncomplete Proteins Contain all 8 essential amino acids Do NOT contain all 8 essential amino acids (“partial proteins”) “Animal” proteins“Plant” proteins Fish, meat, poultry, eggs, yogurt, milk, cheese Legumes, grains, nuts, seeds, beans, corn

**Incomplete proteins must be combined to obtain all 8 essential aa’s: 

**Incomplete proteins must be combined to obtain all 8 essential aa’s: EXAMPLES: Grains and Legumes  peanut butter + whole wheat bread  rice + beans  bean soup + roll  tofu vegetable stir-fry + rice/pasta Grains + Nuts  whole wheat bun + sesame seeds  rice cakes + peanut butter  breadsticks rolled in sesame seeds Legumes + Nuts  hummus (chickpeas + sesame paste)  trail mix (peanuts + sunflower seeds) OR 

**Add small amounts of animal protein to any group to get a complete protein e.g. yogurt + granola macaroni + cheese oatmeal + milk bean + cheese burrito salad with beans + hard boiled egg

1) Kwashiorkor  causes fluid retention (edema), dry skin, hair discoloration  liver enlargement and fluid retention can distend the abdomen and disguise weight loss  anemia, diarrhea, and fluid and electrolyte disorders are common

Proteinuria  Protein (ex. albumin) present in the urine  usually a sign of kidney disease or renal complications of another disease (ex. hypertension or heart failure)  can result from heavy exercise or fever

 High cholesterol can lead to atherosclerosis, coronary artery disease and strokes  On its own, cholesterol is healthy around the body: › Found in cell membranes › Crucial for growth in babies

 Cholesterol is a lipid, it can't dissolve in water or blood › It needs “help” to get through the body  Cholesterol combines with protein, forming a lipoprotein (lipid + protein) › The protein coats the cholesterol › 2 types: high density (HDL) and low density (LDL)

 More protein than cholesterol  Drives like a FERRARI, speeding straight to the liver, then gets converted into bile acids  “Good" cholesterol › Protects against heart attack › Removes excess cholesterol from arterial plaque, slowing its buildup

 More cholesterol than protein  Drives like an old beater, runs into arterial walls, adds to platelets and plaque  “Bad” cholesterol › Plaques can lead to heart attacks etc.

 Type of fat made in the body  Elevated triglycerides can be due to: › obesity, inactivity, smoking, excess alcohol consumption and >60% dietary carbohydrates  High triglycerides often accompanies high total cholesterol level › high LDL (bad) level and a low HDL (good) level

 Genetic variation of LDL (bad) cholesterol  High level is a risk factor for fatty deposits in arteries › May interact with substances found in artery walls and contribute to the buildup of fatty deposits