NFSC100 The Genome DNA Strands of ALL the DNA deoxyribonucleic acid Contains all genetic information in the body housed in the cell nucleus and mitochondria Genes are the DNA sequences in the genome that are expressed in the form of protein or RNA We have about 46 chromosomes 23 pairs RNA Ribonucleic Acid Messenger RNA Intermediates between genes and proteins Transfer RNA carry amino acids Ribosome RNA part of ribosome Both tRNA and rRNA are functional units required for translation Structural differences Ribose RNA not deoxyribose DNA Uracil U replaces T DNA vs RNA Gene Expression How genetic information can be faithfully transmitted A matches with T U G matches with C The DNA serves as a template to make strands of mRNA The mRNA exits the nucleus of the cell through the nuclear membrane while the DNA stays inside the nucleus The mRNA attaches itself to the ribosomes while the tRNA collects amino acids from the cell fluid and brings them to the messenger When the mRNA calls for an amino acid the tRNA carries it and snaps it into position 40 to 100 amino acids can be added to a growing protein strand in 1 second Transcription DNA to mRNA Translation mRNA to protein tRNA and rRNA assist in translation How is Nutrition related to genetics Vitamins work at the genetic level to turn gene expression on or off Nutrients involved in gene expression Some nutrients when in excess can cause damage on DNA Selenium iron phenylalaine some amino acids Vitamin D Calcium Nutrient Regulation of Gene Expression Transcriptional Level Vitamin D Regulates calcium absorption Translational Level Iron When iron is high mRNA of an iron storage protein undergoes When iron is low mRNA of an iron storage protein is blocked from translation translation Translational Level Selenium Deficiency results in mRNA degradation Nutrigenomics to diet The study of how naturally occurring chemicals in foods alter gene expression in each individual Understanding of differences and similarities in gene expression in response Defects in genetic code cause nutrition related diseases mutations Hemochromatosis o Excessive iron accumulation due to mutations in genes involved in iron absorption o Symptoms liver cirrhosis cancer diabetes and heart failure Phenylketoniuria PKU o Inborn error of metabolism o Build up results in brain damage o Dietary limitation limited intake of protein Sickle Cell Disease o One amino acid in the protein strands of hemoglobin takes the place of another causing the red blood cell to change shape and lose function Significance of Nutrigenomics Identification of specific genes may better focus treatment Use to set RDA s more accurately Epigenetics in the DNA sequence expression The science of heritable changes in gene function that occur without a change Modifications on DNA Methylation on cytosine leads to less gene Modifications on histone histone more packed leads to less gene expression Epigenome consists of proteins and other molecules that act to regulate the expression of genes on the strands of DNA turning the genes on or off does not change DNA sequence DNA Methyl group and gene expression effect of diet The B vitamins Volate and B12 are essential for transferring methyl groups Our Diets and the Environment Large scale conventional farming Depletes soil of nutrients Fertilizer runoff causes algae overgrowth dead zones Pesticides and herbicides kill insects and native plants Loss of land environmental destruction deforestation Energy intensive US food industry uses over 20 of the nations fuels Food Processing 6560 calories of fuel used to produce a can of corn 2100 calories of fuel used to produce diet soda Solution Eat less processed foods Large Scale Meat Production Manure results in soil and water pollution Animals are fed grain 1 5 of all cropland in the US is used to produce grain for livestock more than for people Energy Intensive o Takes 8 lbs of grain to produce 1 lb of weight gain in a cow Greenhouse gases o The amount of pollution produced by a cow is comparable to that by a car in a day Solution eat less meat if eating meat find locally sustainably raised grass fed Use water bottles energy efficient dishwashers reusable grocery bags reusable pans recycle Oil and Foods Extreme oil may replace dwindling supplies but it comes at a heavy economic and environmental cost Peak oil is the phenomenon whereby global oil supplies will peak then decline with extraction growing increasingly costly Today s globalized industrial food system depends on oil for fueling farm machinery producing pesticides and transporting goods Biofuels production links oil prices to food prices To Adapt Reduce oil in food production Reduce food transportation distance Increase food system energy efficiency and renewable energy Change food consumption pattern Low oil foods Renewable Energy Glucose ethanol fuel Sugarcane yeast sucrose Corn enzymes and yeast starch Cornstalk grass wood chips challenging cellulose Carbohydrates possible used as fuel eventually Goal to crack the cellulose and lignin that make grasses cornstalks and wood chips into ethanol instead of using corn kernel Algae Biofuel Algae grows rapidly turns carbon dioxide and sunlight into oil Not picky about water quality No need for nutrient rich land little to no competition with food production Lower carbon dioxide green house gas USDA Certified Organic The National Organic Standards Board NOSB USDA prohibits use of toxic and persistent chemicals in favor of more earth friendly practices Crop rotation Planting cover crops Releasing beneficial insects Adding composted manure Field must be free of synthetic pesticides and fertilizers for 3 years before a certified organic crop can be grown on it Use of proper manure composting techniques to prevent against foodborne illness Organic eggs meats and dairy products must be from animals that are given 100 organic feed Severe confinement is forbidden No antibiotics or growth hormones Organic food may not be 100 free of pesticides because they are pervasive in the environment Organic products are not higher in vitamins and minerals Labeling 100 organic must contain only organically produced ingredients Organic must consist of at least 95 of organically produced Made with Organic Ingredients must contain at least 70 organic ingredients ingredients Choose Organic Damage to soil water and air from conventional farming Health consequences of pesticides in food and the environment Concern about genetically
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