Plant Science Exam 3 Study Guide LECTURE 15 Agriculture and Human Nutrition 1 Shift from human foraging to farming which formed the basis of advanced civilization in new and old worlds 2 Early plants wheat barley pea lentil 3 Early animals goat sheep dogs 4 Southeast Asia 8000 years ago cultivated RICE MILLET BROOMCORN MILLET RAPESEED and HEMP evidence of domesticated CATTLE PIGS DOG 5 New world modern day Mexico and Peru began cultivating major crops a Mexico beans corn tomato peanut chili peppers squash b Peru South America potato cacao 6 Domesticated Plants become domesticated through artificial selection traits are selected not for survival but for OWN BENEFIT a Domesticated plants are genetically distinct form their wild progenitors b Most domesticated plants COULD NOT SURVIVE IN WILD 7 Cultivated Plants a Plants came from CENTERS OF ORIGIN and were then dispersed and spread to other parts of b Wild ancestors of domesticated plants still exist and help maintain genetic diversity of crop world plants 8 Modern Agriculture Food and fiber growth is only on 3 of the planet s land 9 U S Agriculture a U S land area is 1 9 billion acres b 16 is crop land c 34 is for pasture and grazing d 4 major crops CORN WHEAT SOYBEANS HAY are planted on 80 of crop land e Veggies fruits nuts on 7 of land f Cotton on 4 of land g There has been a steady INCREASE in agricultural yield PER ACRE in U S crops WITHOUT any significant increase in new land Human Nutrition 10 Calorie a measure of energy the amount of energy required to raise 1 gram of water 1 Degree C a Food energy measured in KILOCALORIES kcal 1000 calories b Kcal energy needed to raise 1 LITER of water 1 degree C c Humans need 1200 3000 calories per day depending on age sex and activity level 11 MACROnutrients required in large amounts the FUEL needed for CELLULAR RESPIRATION 3 types a Carbohydrates 4cal gram composed of C H O and divided into 3 categories i Monosaccharides basic building blocks of all carbohydrates 1 Glucose most abundant monosaccharide transported in blood and is metabolized during cellular respiration to produce ENERGY 2 Also include fructose and galactose ii Disaccharides composed of 2 monosaccharides joined together 1 Sucrose table sugar MOST COMMON disaccharide 2 Glucose fructose sucrose 3 Other disaccharides include lactose milk sugar Maltose in germinating grains 4 Provide NO nutritional value only calories iii Polysaccharides contain hundreds of thousands of INDIVIDUAL SUGAR UNITS usually glucose 1 Known as COMPLEX CARBOHYDRATES 2 Starch long glucose chain found stored in plants potato wheat rice beans corn 3 Starch is broken into glucose by enzymes in the salvia 4 Glycogen the STORAGE FORM of glucose in the human body 5 Excess glucose is converted into fat 6 FIBER a polysaccharide derived from PLANTS a Comes from CELLULOSE cell wall of plants which is composed on many glucose b Not digestible but provides BULK c Dietary fiber can be i Soluble found in oat reduces cholesterol levels and risk of heart disease ii Insoluble found in fruit bran vegetables Absorbs water prevents constipation may prevent certain cancers colorectal b Proteins 4 cal gram large complex molecules that perform many bodily functions i Made from small building blocks called amino acids 20 diff kinds ii Sources of proteins meat fish cheese milk egg beans corn soy bean whole wheat bread oatmeal peanut butter iii Body cells make 11 out of 20 AMINO ACIDS but it CANT MAKE 9 iv These 9 are called essential amino acids come from diet and cant be stored in the body v Complete proteins contain all the essential amino acids 1 Proteins from animal sources are complete 2 Proteins from plant sources are INCOMPLETE lack 1 or 2 essential amino acids 3 To get ALL ESSENTIAL AMINO ACIDS from plant sources you need to combine different protein plant sources like corn and beans vi Protein digestion requires digestive enzymes also proteins 1 Some proteins egg protein CANNOT BE broken down completely even though egg protein is very complete 2 High quality proteins a Contain all essential amino acids b Are fully digestible c Free their amino acids which are absorbed readily c Fats lipids 9cal gram composed of C H O i Have glycerol head HYDROPHILIC and a HYDROPHOBIC TAIL fatty acid ii NOT SOLUBLE in water iii Cause obesity heart disease but also serve vital functions in body such as ENERGY iv Triglycerides 95 of body lipids 1 Triglycerides glycerol 3 fatty acids 2 Fatty acid chains vary and determine CHARACTERISTS of the triglyceride v Essential fatty acids the 3 fatty acids that the body CANT MAKE and therefore must be provided in the DIET vi Linoleic linolenic and arachidonic acid usually found in vegetable oil vii Saturated vs unsaturated fatty acids 1 Depends on carbon hydrogen bonding on fatty acid chain 2 Saturated fatty acids carbon atoms are joined by a single bond SOLID at room temperature butter lard beef fat a Excess of saturated fat leads to obesity heart disease cancer 3 Unsaturated fatty acids carbon carbon bonds are double bonds LIQUID at room temperature corn oil olive oil safflower oil a Lower risk of heart disease by lowering cholesterol levels omega 3 fatty acids 4 Trans fatty acids are very unhealthy viii Cholesterol 1 Steroids subcategory of LIPIDS 2 Cholesterol makes cell membranes and human HORMONES 3 Animal products like eggs butter meat cheese HIGH CHOLESTEROL 4 Plants provide unsaturated fat which LOWERS cholesterol levels 5 GOOD CHOLESTEROL High density LIPOPROTEIN HDL helps decrease LDL BAD cholesterol levels 6 BAD CHOLESTEROL LOW density LIPOPROTEIN LDL causes blockage of arteries restricts blood flow causing heart attacks MICROnutrients required in small amounts but still essential for proper nutrition 2 kinds of micronutrients VITAMINS and MINERALS 12 VITAMINS some called COENZYMES essential for proper functioning of certain enzymes others are involved in SYNTHESIZING COMPOUNDS divided in two types a Fat soluble Vitamins A D E K b Water soluble Vitamins B complex c 13 Vitamin A a Formation of vision pigments b Also helps maintain smooth healthy skin c Bone and tooth development d Animal sources of Vitamin A liver e Plant sources of Vitamin A yellow orange and dark green fruits and vegetables f Lack of Vitamin A causes night blindness dry scaly skin infections lack of bone growth 14 Vitamin B Complex a There are 8 vitamins all water soluble b Most act as COENZYMES help in food breakdown and release of energy c Deficiency of Vitamin B