Plants in Human Nutrition, Diet, and Health PDF

Plants in Human Nutrition, Diet, and Health Outline Nutrition from food Macromolecules Carbohydrates Lipids Proteins Vitamins & Minerals Bioactive Molecules The Intestinal Microbiome Vegetarian, Vegan, Organics Nutrition from food nutrients: substances that are necessary for...

Plants in Human Nutrition, Diet, and Health Outline Nutrition from food Macromolecules Carbohydrates Lipids Proteins Vitamins & Minerals Bioactive Molecules The Intestinal Microbiome Vegetarian, Vegan, Organics Nutrition from food nutrients: substances that are necessary for the body’s growth, maintenance, and function, which must be obtained from food 1)carbohydrates 2)_________________ 3)amino acids 4)vitamins 5)minerals You are what you …. ingest ~65% water ~35% other molecules  Energy vs. Nutrients Energy requirements o Measured in calories o Harvested by removing energy from chemical bonds Nutrient requirements o Amount of each nutrient required by most people o ___________ should be higher than the established minimum How were these determined? o Clinical trials, quasi-experimental, animal studies, cohort studies … and from all of these, meta-analysis (lots of scientific research) Macromolecules large, often complex chains (polymers) of molecules created by the bonding together (polymerization) of individual units called monomers 1.Carbohydrates 2._____________ 3.Lipids Carbohydrates – heavy energy molecules All sugars loosely defined as molecules that contain carbon, hydrogen, and oxygen in a 1:2:1 ratio (CH2O)n Monomer = “monosaccharides”, simple sugars o e.g. glucose; fructose Polymer = “polysaccharides” o Disaccharide eg. glucose + fructose = sucrose o Storage: starch o Structural: cellulose Monosaccharides: (CH2O)x Named based on the number of carbons x = 3 = glyceraldehyde x = 5 = pentoses x = 6 = hexoses Monosaccharides: (CH2O)x Often form rings with oxygen as a member (displaces one carbon out of the ring) Starch is used for storage, cellulose is used for structure, both are polymers of glucose - biochemistry matters! Alpha 1,4 bond o starch o hydration causes it to form an open spiral; easy for enzymes to get in and hydrolyze Beta 1,4 bond o 𝞫-bond causes the monosaccharides to flip; o cellulose forms a rod and is much less accessible to enzymes because adjacent chains bond together (insoluble) Lipids – light-weight energy molecules All are insoluble in water fats, oils, sterols o e.g. triglycerides; cholesterol, phospholipids o triglycerides and phospholipids both have glycerol and fatty acids Lipids – light-weight energy molecules All are insoluble in water fats, oils, sterols o e.g. triglycerides; cholesterol, phospholipids o triglycerides and phospholipids both have glycerol and fatty acids o saturated or unsaturated  Hydrogenation Technique to make oils more “firm” and less prone to oxidation (breakdown) o longer storage o flavour and texture Artificial process can lead to trans-fats Some fatty acids are “essential” (cannot be made with human metabolism) Ω-3: linolenic – 2 unsaturated bonds – from flax, canola, safflower, some oily fish, nuts Ω-6: linoleic acid – 3 unsaturated bonds – from chicken, plant oils Too much energy – a bad thing? The expenditure of energy in adult humans comprises two main components: 1. Basal metabolism – metabolism performed as part of daily maintenance and normal growth ~ 1600 calories a day 2. Active metabolism - Conscious muscle movements Affluence and sedentary lives have led to new challenges: -obesity -heart disease: -_________________ syndrome Government suggestions Based on science, availability, economics, and … _______ Canada food guide was revised in 2019. https://food-guide.canada.ca/en/ o Input from industry is forbidden o “Eat food. Not too much. Mostly plants.” ▪ Michael Pollan, 2009 In defense of food. Proteins – “structure molecules” Contain a lot of nitrogen Monomer = ____________acids o e.g. glycine, tryptophan Basic structure: o amino o carboxyl (carboxylic acid) o “R” group (provides distinctive traits) Polymer = “polypeptides” (proteins) 3-D structure allows these to form enzymes, pigments, storage structures … all the cool stuff. Protein assimilation Essential amino acids (9) o must be obtained from food o amino acids come in the form of proteins o due to their varied structures and chemical properties, some proteins are less digestible than others ▪ physical (mastication; cooking) ▪ acid (in stomach) ▪ base (in small intestine) ▪ intracellularly Structures of four of the nine essential amino acids Protein Score o based on digestibility and what essential aā they have o some cultures use complementary foods to adjust Vitamins Small, organic molecules that aren’t macromolecules (or their monomers) that must be eaten Some foods are richer than others Four ways to prevent vitamin deficiencies: 1)balanced diet 2)vitamin supplements 3)_____________ foods 4)genetically engineered plants The strange case of ‘Vitamin D’ o cholecalciferol o formed from cholesterol via sunlight o seems to act as a chemical messenger rather than to assist enzyme functions (therefore a hormone) o many people don’t get enough sunlight o deficiency is associated with rickets, cancer, heart disease, diabetes, autoimmune disorders o other sources include cod liver oil, supplements, and fortified foods  Minerals Obtained through food and the water we drink “micronutrients” Bioactive Molecules Plant biochemistry is much more sophisticated than that of animals o Animals can move around to find food, avoid toxins, evade predators o Plants use ____________ to compensate for being sedentary – often have larger genomes encoding a variety of metabolic paths “Superfoods” Antioxidants o supposed to help eliminate highly reactive oxygen molecules (often called free radicals) o no studies that show antioxidants consistently reduce DNA damage or cancer risk Functional foods o may be supplemented (“fortified”) https://www.abc.net.au/news/health/ 2017-04-21/can-you-have-too-many- antioxidants/8457336 The Intestinal Microbiome Probiotic Bacteria Types or species of bacteria in the human microbiome that are beneficial or essential for proper health Can you think of any foods that could be considered probiotics?  Diets Not one diet is a magic cure for everything Nutritional Deficiencies can lead to acute or chronic health issues o enzymes, organ damage, interactions all affect the complex network of feedback loops that are part of our metabolism Vegetarians and Vegans o often use legumes (13% of humanity’s protein) o Cannot obtain vitamin B12 (easily obtained from meats, but can come from microorganisms) Organic foods – more about ecology than health Next class Plant Domestication and Biotechnology Study Guide from Chapter List the four macromolecule classes used by biologists. Describe the human health implications of the macromolecule classes. Identify (by sight and by listing) the monomers that assemble to form each macromolecule class. Describe the importance of nitrogen in forming proteins. Describe the atoms involved in creating carbohydrates. Distinguish between vitamins and the macromolecule classes. Explain how diseases can form from nutritional deficiencies. Explain how particular choices of diet keep people healthy by paying attention to consumption of specific food types. Describe forms of evidence regarding the benefits or drawbacks of organic food production. Define key terms of the chapter.