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Plant Science Exam 3: Study GuideLECTURE 15: Agriculture and Human NutritionHuman NutritionLECTURE 16: Grasses, Legumes, Starchy staplesGrass General FeaturesOther important grains:LEGUMESSTARCHY STAPLESLECTURE 17: Fibers, herbs and spicesLecture 18: Stimulating BeveragesAll rich in caffeine!Lecture 19: Medicinal, Poisonous and Allergenic PlantsHistory:Western medicine started with Hippocrates “father of medicine” used for diseasesTraditional chinese Meds:Active compounds in medicinal plants:Alkaloids:Glycosides:Most important medicinal plants:Cinchona Tree: MalariaSnakeroot:Aloe:Pacific Yew: Taxus brevifoliaFuture Drugs in Plants:Herbal Remedies:Commonly used herbal Remedies:Plant Science Exam 3: Study GuideLECTURE 15: Agriculture and Human Nutrition1) Shift from human foraging to farming which formed the basis of advanced civilization in new and old worlds2) Early plants: wheat, barley, pea, lentil3) Early animals: goat, sheep, dogs4) Southeast Asia- 8000 years ago; cultivated RICE, MILLET, BROOMCORN MILLET, RAPESEED, and HEMP; evidence of domesticated CATTLE, PIGS, DOG5) New world: modern day Mexico and Peru; began cultivating major cropsa) Mexico- beans, corn, tomato, peanut, chili, peppers, squashb) Peru & South America- potato, cacao6) 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 progenitorsb) Most domesticated plants COULD NOT SURVIVE IN WILD7) Cultivated Plants: a) Plants came from CENTERS OF ORIGIN and were then dispersed and spread to other parts of worldb) Wild ancestors of domesticated plants still exist and help maintain genetic diversity of crop plants8) Modern Agriculture: Food and fiber growth is only on 3% of the planet’s land9) U.S. Agriculture: a) U.S. land area is 1.9 billion acresb) 16% is crop landc) 34% is for pasture and grazingd) 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 landg) **There has been a steady INCREASE in agricultural yield PER ACRE in U.S. crops; WITHOUT any significant increase in new landHuman Nutrition10) Calorie- a measure of energy; the amount of energy required to raise 1 gram of water 1 Degree Ca) Food energy measured in KILOCALORIES (kcal= 1000 calories)b) Kcal= energy needed to raise 1 LITER of water 1 degree Cc) Humans need 1200-3000 calories per day, depending on age, sex, and activity level11) MACROnutrients- required in large amounts; the FUEL needed for CELLULAR RESPIRATION 3typesa) Carbohydrates (4cal/gram)- composed of C,H,O and divided into 3 categoriesi) 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 galactoseii) 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 caloriesiii) 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 functionsi) 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 butteriii) Body cells make 11 out of 20 AMINO ACIDS but, it CANT MAKE 9iv) These 9 are called essential amino acids- come from diet, and cant be stored in the bodyv) 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 readilyc) Fats/ lipids (9cal/gram)- composed of C, H, O i) Have glycerol head (HYDROPHILIC) and a HYDROPHOBIC TAIL (fatty acid)ii) NOT SOLUBLE in wateriii) Cause obesity, heart disease but also serve vital functions in body such as ENERGYiv) Triglycerides- 95% of body lipids(1) Triglycerides= glycerol+ 3 fatty acids(2) Fatty acid chains vary and determine CHARACTERISTS of the triglyceridev) Essential fatty acids- the 3 fatty acids that the body CANT MAKE, and therefore must be provided in the DIETvi) Linoleic, linolenic and arachidonic acid- usually found in vegetable oilvii)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 unhealthyviii) 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)


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UMD BSCI 124 - Exam 3

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