What are the ingredients of Plants? A was wrong to 99.9 % biomass Conclusion from Helmont’s experiment Î most of the mass of plants is made up by water! 90 % What are the ingredients of Plants? How do plants and animals differ as food for humans? Î Î Î The role of plants changed with time from emphasis shifting from minerals to vitamins to fiber to necessary supplements of our intake. Why are plants the masters in biosynthesis? The major reason is that plants have chloroplasts. CHLOROPLASTS: -are domesticated former cyanobacteria that have been swallowed and accommodated inside the cells of the ancestors of green alga and plants -Photosynthesis allows algae and plants to produce a nearly limitless supply of sugars and other organic compounds that they use to bribe or repel other organism, e.g. bacteria around their root, insects for protection & pollination -retained their own DNA and also ribosomes to synthetize amino acids and proteins/enzymes that add to the biochemical potential of the host cell. Their biochemical abilities make plants the primary producers of biomass on the planet. They also give them the ability to attract (sugar, smells, pheromones) or repel (poison) other forms of life. Plants are masters in symbioses and networking. The endosymbiont Theory of Evolution (1) 1883 Botanist Andreas Schimper observed that the division of chloroplasts in plants closely resembled that of free-living cyanobacteria, (2) 1905 endosymbiotic theory was first articulated by the Russian botanist Konstantin Mereschkowsky (3) 1920s Ivan Wallin extended the idea of an endosymbiotic origin to mitochondria coming from aerobic bacteria or Ricketsia (4) 1960 Chloroplasts & mitochondria have their own particular DNA and ribosomes (smaller size than nucleus) (5) 1981 Lynn Margulis popularized these ideas in her book “ Symbiosis in cell evolution” Examples of metabolites that plants produce but humans cannot (must import with food!) (1) A vitamin is an organic compound required by an organism as a vital or essential part of its diet because it cannot be synthesized in sufficient quantities by the organism. The term vitamin does not include other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids which are needed in larger amounts than vitamins, nor does it encompass the large number of other nutrients that promote health but are otherwise required less often.[2] Thirteen vitamins are recognized at present. (2) Nine amino acids are essential for humans: phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, leucine, and lysine. Arginine is required by infants and growing kids, it is an important supplement in producing nitric oxide. (3) Essential Fatty Acids or EFAs, are those required for biological processes, and not those that only act as fuel. Two EFAs are known for humans: alpha-linolenic acid (an omega-3 fatty acid) & linoleic acid (an omega-6 fatty acid. When the two EFAs were first discovered in 1923, they were designated Vitamin F. In 1930, work showed that the two EFAs are better classified as fats than vitamins. Guess why? Other essential acids Essential substances are such that humans & other animals must ingest because their body requires them for functioning although they cannot synthesize them on their own. Nine amino acids are essential for humans: phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, leucine, and lysine. Essential fatty acids, or EFAs, are those fatty acids that are required for biological processes, and not those that only act as fuel. Two EFAs are known for humans: alpha-linolenic acid (an omega-3 fatty acid) & linoleic acid (an omega-6 fatty acid. When the two EFAs were first discovered in 1923, they were designated Vitamin F. In 1930, work showed that the two EFAs are better classified as fats than vitamins By convention, the term vitamin refers to essential organic substances that are needed in small quantity and does not include other essentials such as minerals, essential fatty acids, or essential amino acids needed in larger amounts . Thirteen vitamins are universally recognized at present, vital amines Î Vitamines are not amines A vitamin is an organic compound required by an organism as a vital or essential part of its diet because it cannot be synthesized in sufficient quantities by the organism. The term vitamin does not include other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids (which are needed in larger amounts than vitamins), nor does it encompass the large number of other nutrients that promote health but are otherwise required less often.[2] Thirteen vitamins are universally recognized at present. 1747 British Navy doctor James Lind examined 12 sailors with scurvy Î treatment of 2 each with (1) cider, (2) vinegar, (3) sea water (4) nutmeg, (5) a medicinal powder and (6) lemons & oranges. The limeys recovered. Ascorbic acid (vitamin C) is a vitamin for humans, but not for most other animals. Essential for health of connective tissue. Vit.C. and tocopherol (vitamin E) are antixoidants. 1897 Dutch scientist found that the Beriberi disease (lethargy due to ailment of nervous system) came from eating polished white rice rather than whole grains.. The ailment was caused by a thiamine (vitamin B1) deficiency in the diet. 1913 Vit A was discovered in egg yolk and cod liver oil as a remedy for Night blindness as one of the first signs of vitamin A deficiency. Ancient Egyptians fed raw liver. "vitamin A", which includes the compounds retinal, retinol, & 4 carotenoids. It is not an amine. Why are plants the masters in biosynthesis? Primary metabolism is that of nucleic acids, amino acids, proteins, lipids, and carbohydrates. It is all the same from archaebacteria to plants. Primary metabolism is different in plants & animals: plants are N-starved animals too much Î urine Î hairs in plants cellulose in animals protein = keratin plants have plenty of CH (phot) animals need to eat to get it plant produce all essential AAs animals need to eat AAs plants produce all vitamins animals produce only a few plants produce 10 ooo alkaloids animals 30 to 50 alkaloids plants do not need only light animals need to eat ! Secondary metabolites 1. often excluded from metabolism (nicotine carotene biosynthesis inh.) (a) external excretion into the cell walls (b) internal excretion into vacoles (trash cans; Paech) 2. Have specific action (atropine toxinf or humans not for rabbits & pigs) 3. Have ecological significance for survival of species 4. Are characteristic for certain families (brassica mustard oil. Inulin in Asters) Secondary metabolites have ecological meaning – ahh in plants Primary vs secondary metabolites are defined by function. When non- proteinogenic AA canavanine mimicks biochemistry of arginine it is a secondary Toxin leading to malfunctioning enzymes. Citric acid is a central molecule in primary metabolism (citrate cycle). However, when stored in vacuoles, it serves as an antibiotic protectant for the plant cells. Meaning: Why do Plants produce a Latex Polymer? 1905 H Kniep carried out classical experiment on chemical defense in plants. By repeated poking the midvein of Euphorbias he drained/milked them & found them now being eaten by snails. Kniep did not know that some insects have practiced his method regularly to avoid being poisoned or muzzled alive! Drain the lacticifer defense chemicals or suffer the consequences!1 R: Thomas Eisner “ For love of insects” Harvard University Press, 2003 Primary & Secondary metabolites Primary Metabolites: Secondary Metabolites: Sugar, starch, citric acid, Vitamines Pectins & algins (food additives) Phenolic compounds (coffee, vine, incense, perfumes) protein (seeds of Fabaeceae) Terpenoid compounds plant fatty oils (nuts, corn, (lemon scent, anis taste, bitter sesame, peanuts, sunflower, rape) taste of hops, tonic water, color cellulose (cotton, fiber, wood) Amines (smell of fish, algae, ) Alkaloids (coffeine etc.) Glycosides (Sinigrin from mustard, allicin from garlic, PEA in chocolate) What are primary metabolites made of? Primary metabolites have no less medical effects than secondary metabolites We eat plant foods because of 1. Vitamins 2. Roughage or fiber 3. Necessity for a balanced diet since our ancestors were fruit eaters. 4. Carnivory was only a short period associated with the primate-hominid transition and self-recognition of humans - the only killer primates known to us animals What are Primary metabolites made of? Mono- and disaccharides – the primary products of photosynthesis galactose Dietary fiber Mechanical Fiber Cellulose is the major ingredient of cell walls in the kingdom of Plantae. Chitin – a N-containing polymer is characteristic for the walls of fungus cells and the skeleton of insects. Lignin is a phenolic plant polymer Î to this! From this … Ligninis a polyphenolic polymer resin that forms stiff wood with cellulose in secondary cell walls of plants and algae. The monomers are ferulic, gallic & coumaric acids + syringyl alcohol What is wood? Cellulose is the major ingredient of cell walls in the kingdom of Plantae. Chitin – a N-containing polymer is characteristic for the walls of fungus cells and the skeleton of insects. Wood is a composite of two ingredients: fiber + resin The two ingredients: fiber is cellulose imbedded in a resin called lignin. Ferulic acid Ferulic acid is phenolic phytochemical found in plant cell walls. It iscomponent of lignocellulose, crosslinking lignin & polysaccharides, thereby conferring rigidity to the cell walls of beets, red beets, water chestnuts. A good amount is found in oats, brown rice, whole wheat, peanuts, apples, and pineapples as well as in coffee, apple, artichoke, peanut, oranges. Name derives from Ferula, giant fennel. Tumeric Cucurma Chemical structure resembles that of cucurmin – longa & its rhizome Unlignified primary cell walls containing ester-linked ferulic acid fluoresce blue in ultraviolet radiation which changes to green on treatment with ammonium hydroxide. Using this fluorescence test, we detected ester-linked ferulic acid in the primary cell walls of all 41 species of gymnosperms.