The genomeStrands of ALL the DNA (Deoxyribonucleic acid)Contains all genetic information in the body housed in cell nucleus and mitochondriaGene vs. genomeGenes are the DNA sequences in the genome that are expressed in the form of protein or RNA (to a limited extent)Not all DNA sequences in the genome are expressedHow many genes we have?20,000-30,000 genesRNA (Ribonucleic acid)Three major typesThe intermediate product of the gene after transcription1. Messenger RNA (mRNA): intermediates between genes and proteinsfunctional units required for translation2. Transfer RNA (tRNA): carry amino acids3. Ribosome RNA (rRNA): part of ribosomeGene Expression SummaryNuclear DNA makes mRNA copymRNA leaves nucleus – DNA stays behindmRNA attaches to ribosomes (composed of rRNA)tRNA has been collecting amino acids from cytoplasmtRNA’s give up their amino acids to the proteins being synthesized in the ribosomean enzyme then bonds one amino acid to the nextthe protein is then released if the stop codons followHow is nutrition related to genetics?Vitamins work at the genetic level to turn gene expression on or offSome nutrients when in excess can cause damage on DNASome antioxidant nutrients can counteract oxygen free radicals and thus inhibit oxidation on DNANutrients involved in gene expressionSeleniumIronSome amino acids (phenylalanine)Vitamin D/CalciumNutrient regulation of gene expression at translational levelIronIron effects mRNA translation of proteins involved in iron storageWhen iron is high, mRNA of an iron storage protein undergoes translationWhen iron is low, mRNA of an iron storage protein is blocked from translationSeleniumSelenium deficiency results in selenoprotein mRNA degradationNutrigenomicsThe study of how naturally occurring chemicals in foods alter gene expression in each individualIdentification and understanding of population differences and similarities in gene expression, or phenotype, in response to dietHow is nutrition relation to human genetic diseases?Defects in genetic code cause nutrition related diseases (mutations)Hereditary hemochromatosisA human autosomal, recessive disorderCause: excessive iron accumulation due to mutations in genes involved in iron absorptionSymptoms: liver cirrhosis, cancer, diabetes, and heart failurePhenylketonuriaInborn error of metabolismA genetic disorder, with mutations in the gene that metabolites phenylalanineBuildup of phenylalanine results in brain damageWhat is the dietary limitation for PKU patients?Artificial sweeteners, things that have phenylalanineSickle cell diseaseOne amino acid in the protein strands of hemoglobin takes the place of another, causing the red blood cell to change shape and lose functionEpigeneticsThe science of heritable changes in gene function that occur without a change in the DNA sequenceModifications on DNA (methylation on cytosine, one of the four DNA bases: decreased gene expression)Modifications on histone proteins (for example, acethylation on histone)The B vitamins, folate, and B12 are essential for transferring methyl groupsSignificance of nutrigenomicsEarly detection may aid with prevention, or may cause undue worryIdentification of specific genes may better focus treatmentCan use as better assessment of nutritional statusUse to set RDAs more accuratelyOur diets and the environmentLarge scale conventional farmingConventional farming depletes soil of nutrientsFertilizer runoff causes algae overgrowth (dead zones)Pesticides and herbicides kill insects and native plantsLoss of land, environmental destruction (deforestation)Energy intensiveIn the US, the food industry uses 20% of the nation’s fuel to run farm machinery and produce fertilizers and pesticides, and to prepare, package, transport, refrigerate, and otherwise store, cook, and wash our foodsSolutions: organic, sustainable, locally grown produceFood processing6,560 calories of fuel are used to produce a can of corn2,100 calories of fuel are used to produce a diet soda500 for the soda1600 to make the cansolution: eat food that is less processedLarge scale meat productionManure results in soil and water pollutionAnimals are fed grain1/5 of all cropland in the US is used to produce grain for livestock (more than for people)energy intensivetakes 8 lbs of grain to produce one lb of weight gain in a cowgreenhouse gasthe amount of pollution produced by a cow is comparable to that by a car in a daysolution: eat less meat, if eating meat, find locally/sustainably raised, grass fedwater bottlesenergy efficient dishwashers, only running full dishwasherreusable grocery bagsreusable pans, dishes rather than disposablesReduce, Reuse, RecycleThe future of oil?“extreme oil” may replace dwindling supplies, but it comes at a heavy economic and environmental costoil and foodspeak oil is the phenomenon whereby global oil supplies peak, then decline, with extraction growing increasingly costlytoday’s globalized industrial food system depends on oil for fueling farm machinery, producing pesticides, and transporting goodsbiofuels production links oil prices to food pricesadaptations of food systems for peak oil erareduce oil in food productionincrease food system energy efficiency and renewable energychange food consumption pattern – “low oil foods”reduce food transportation distancealternative energy: algae biofuelwhy algae?1. Grow rapidly: turning carbon dioxide and sunlight into oil2. Not picky about water quality3. No need for nutrient-rich land: little no competition with food production4. Lower carbon oxide green house gasUSDA Certified OrganicUSDA implemented organic standards in 2002Established regulations for organic farming and labeling of organic productsHow the rules regulation organic matters are decidedThe National Organic Standards Board (NOSB) typically meets twice per year in various locations around the US. During meetings, they listen to public comments, discuss their agenda items, and then vote in a public forumProhibits use of toxic and persistent chemicals in favor or more earth friendly practicesCrop rotationPlanting cover cropsReleasing beneficial insectsAdding composted manureField must be free of synthetic pesticides and fertilizers for 3 years before a certified organic crop can be grown on itUse of proper manure-composting techniques to prevent against foodborne illnessOrganic eggs, meats, and dairy products must be from animals that are given 100% organic feedSevere confinement is forbiddenNo antibiotics or growth
View Full Document
Unlocking...