Exam III Study GuideLecture 15: Human Uses of PlantsIntro to Agriculture – the science, art, and practice of cultivating the soil, producing crops and raising livestockI. Early Sites of AgricultureA. the near East, the “fertile crescent” of MesopotamiaB. the far East – Southeast Asia, the Yellow and Yangtze riversC. New World – modern day South American and Peru – potato, cacao; Mexico – beans, corn, tomato, peppers, squashD. Modern agriculture – 3% of the planet’s land, 97% of the land is non-crop or non-grazing, its tundra, desert, forest mountain, and tropical forestE. Agriculture in the US – land area is 1.9 billion acres; 16% is used as crop land, 34% is used for pastureand grazinga. Four major crops are planted on 80% of crop land – corn, wheat, soy beans, and hayb. Vegetables, fruits, nuts are produced on 7% of the crop land, cotton on 4% of the landc. Steady increase in agriculture b/c of improved crop varieties, practices, pest control, and tailored fertilization of cropsII. Human Nutrition A. Macronutrients – 3:a. Carbs = 4cal/g; composed of:i. Monosaccharides - basic building block; glucose is metabolized during cellular respiration to produce energy; fructose and galactoseii. Disaccharides – composed of 2 monosaccharides joined together; sucrose is the most; glucose + fructose = sucrose; others include lactose (milk sugar), maltose (found in germinating grains); no nutritional valueiii. Polysaccharides – contain hundreds of thousands of individual sugar units; complex carbs; starch (long glucose chain found stored in plants (potato, wheat, rice); glycogen –storage form of glucose in the human body; excess glucose is converted into fat1. Fiber – derived from plants; comes from cellulose; not digestable but provides bulk; dietary fiber can be soluble – found in oat, reduces cholestrol levels and risk of heart disease; insoluble – found in fruit, bran, vegetables; absorbs water, prevents constipation and may prevent certain cancers (colorectal)b. Protein = 4cal/gi. Large complex molecules; made from amino acids – there are 20 ii. Cells in the body take 11 out of 20 amino acids; but 11 amino acids cannot be madeiii. 9 essential ones – must come from the dietiv. complete proteins – contain all the essential amino acids; animal sources are complete; proteins from plant sources are incomplete, combine different protein plant sources to get all essential onesv. digestion – requires digestive enzymes; some proteins (egg) cannot be broken down, high quality proteins contain all essential, can be digested, free their amino acidsc. Fats = 9 cal/gi. Saturated vs. unsaturated:1. Depends on carbon-hydrogen bonding of fatty acid chain; carbon atoms are joined by a single bond (saturated), double bonds are unsaturated2. Saturated – solid @ room temp. butter, lard, beef fat3. Unsaturated – liquid @ room temp. corn oil, olive oil4. Unsaturated fats lower risk of <3 disease by lowering cholestrol levels, Omega-3 fatty acidsii. Cholestrol1. Subcategory of lipids called steroids, important for making cell membranes and human hormones 2. Eggs, butter, meat, cheese – high chol.3. Good vs. bad cholestrol – LDL = bad, HDL = good, helps decrease LDLB. Micronutrients – required in small amounts; 2 kinds:a. Vitaminsi. Vitamin A – formation of vision pigments, healthy skin, bone/tooth development, animal sources = liver, plant sources = yellow, orange, dark green fruits, lack of causes night blindness, lack of bone growthii. Vitamin B complex – 8 vitamins, all water soluble; act as coenzymes, help in food breakdown/release of energy, deficiency causes fatigure, weakness, depression, anemia, good sources = meat, fish, chicken, whole grains, seeds; B12 only from animalsiii. Vitamin C – important role in synthesis of collagen (connective tissue of cells), found in bones, teeth; good antioxidant helps in absorption of iron, lack causes scurvy – bleedinggums, fatigue, brittle bones iv. Vitamin D – helps to regulate calcium and phosphorus levels in normal bone development; can be synthesized on exposure to sunlight, lack causes bone malformation called rickets, does not occur in plants, milk/dairy productsb. Mineralsi. calcium – most abundant, lack causes osteoporosis, milk/dairy products are good sourcesii. iron – trace mineral (needed in smaller amounts), functions as component of hemoglobin, molecule that carries oxygen in red blood cells, lack can cause anemia, good sources are liver, fish, poultry, leafy veggies, dried fruits, legumesiii. iodine – trace mineral required for the formation of thyroid hormones, lack causes goiter – swelling of the thyroid gland; iodized salt is best sourceIII. Dietary GuidelinesA. Food PyramidLecture 16: Grasses, Legumes, Starchy StaplesI. Grasses – make up 25% of world’s vegetation, monocots – herbaceous parallel leaf venation, flower parts in three’s, scattered vascular bundles, fibrous rootsA. include grains, edible grains of cultivated grasses = cereals, major suppliers of calories, advantage – dryseeds can be stored for years, concentrated food sourceB. Flowers of grasses – inflorescence is the structure containing all the flowers; perfect = bisexual, wheat or rice; imperfect = unisexual, corn; wind pollination; anthers are large/produce a lot of pollen, stigmas are double/large, to catch pollenC. Grass fruit – have simple, dry fruits that do NOT open @ maturity, caryopsis – seed coat is fused to the ovary wall (corn, wheat, rice); dries until it’s 5-15% water, can withstand extreme cold, heat; grain parts include:1. endosperm – (3n) large cells filled with starch grains, supplies food to germinating seedling2. embryo (or germ) – (2n) young plant rich in oils, proteins, vitamins3. bran – outer layers of old fruit wall, seed coat, and aleurone layer (secretes enzymes that digest the stored starch in the endosperm, rich in protein/vitamins)D. Wheat – most widely cultivated grain, cool dry climate, origin = wild wheat species found in near east crossed, forming polypoid species that are used todayi. Types – durum (pasta), bread wheat (high gluten – protein that gives bread elasticity), together with a leavening agent (yeast or baking soda) is added to produce CO2 bubbles, which are trappedand make the dough riseii. Wheat nutrition – great source of carbs and fiber, contains 13% protein; concentrated in the bran and germiii. Corn or maize – origin – central