Exam 4 11 20 2012 Nutrients and gene regulation From DNA to Living Cells The Genome Strands of all the DNA deoxyribonucleic acid Contains all genetic information in the body housed in cell nucleus Gene does not equal genome genes are the DNA sequences in the genome that are expressed in the form of protein or RNA to a and mitochondria limited extent Not all DNA sequences in the genome are expressed How many genes we have RNA Ribonucleic Acid Three major types o The intermediate product of the gene after transcription 1 messenger RNA mRNA intermediates between genes and proteins o functional units required for translation 2 Transfer RNA tRNA carry amino acids 3 Ribosome RNA rRNA part of ribosome DNA vs RNA Watson and Crick 1962 Novel Prize in physiology or medicine Structural Differences between DNA and RNA o 1 ribose but not deoxyribose o 2 Uracil replaces T The Endless ATGC combinations make life possible In 1968 Nirenberg Khorana were awarded the Nobel Prize for the elucidation of the GENETIC CODE Gene Expression o How genetic information can be faithfully transmitted A matches with T U G matches with C transcription DNA mRNA translation mRNA protein tRNA and rRNA assist in translation Gene Expression Summary Nuclear DNA makes mRNA copy mRNA leaves nucleus DNA stays behind MRNA attaches to ribosomes composed of rRNA tRNA has been collecting AA from cytoplasm tRNA s give up their AA to the proteins being synthesized in the ribosome an enzyme then bonds one AA to the next the protein is then releases if the stop codons follow How is Nutrition related to genetics Vitamins work at the genetic level to turn gene expression on or off Some nutrients when in excess can cause damage on DNA Some antioxidant nutrients can counteract oxygen free radicals and thus inhibit oxidation on DNA Nutrient involved in Gene Expression Iron Selenium Some amino acids phenylalanine Vitamin d calcium Nutrient Regulation of Gene Expression at Transcriptional Level Why vitamin D can increase calcium bioavailability o o Iron Nutrient Regulation of Gene expression at Translational Level o Iron effects mRNA translation of protein involved in iron storage translation o When iron is high mRNA of an iron storage protein undergoes o When iron in low MRNA of an iron storage protein is blocked from translation Selenium degradation Nutrigenomics o Selenium deficiency results in selenoprotien mRNA The study of how naturally occurring chemicals in foods alter gene expression in each individual Identification and understanding of population differences and similarities in gene expression or phenotype in response to diet How is nutrition related to human genetic diseases Defects in genetic code cause nutrition related diseases mutations o Hereditary hemochromatosis A human autosomal recessive disorder Cause excessive iron accumulation due to mutations in genes involved in iron apportion Symptoms Liver cirrhosis cancer diabetes and heat failure o Phenylketonuria Inborn error of metabolism Phenylketonuria PKU a genetic disorder with mutations in the gene that metabolites phenylalanine Build up of phenylalanine results in brain damage What is the dietart limitation for PKU patients P 71 What doe autosomal recessive mean Sickle Cell Disease Point mutation o Epigenetics bases histone The science of heritable changes in gene function that occur without a change in the DNA sequence Modifications on DNA methylation on cytosine one of the four DNA Modifications on histone proteins for example acethylation on Two epigenetic factors and gene activity o 1 Methylated cytosine decreased gene expression o 2 Histone modifications histone more packed decreases gene expression DNA methyl group and gene expression effect of diet The B vitamins folate and B12 are essential for transferring methyl o groups Significance of nutrigenomics Identification of specific genes may better focus treatment Early detection may aid with prevention or may cause undue worry Can use as better assessment of nutritional status Use to set RDAs more accurately 11 20 2012 Sustainability Agriculture nutrition and food Our diets and the environment Large scale conventional farming o Conventional farming depletes soil of nutrients o Fertilizer runoff causes algae overgrowth dead zones o Pesticides and herbicides kill insects and native plants o Loss of land environmental destruction desforestation o Energy intensive In the US the food industry uses 20 of the nations fuels to run farm machinery and produce fertilizers and pesticides and to prepare package transport refrigerate and otherwise sore cook and wash our foods Food Processing o solutions organic sustainable locally growth produce o 6 560 calories of fuel are used to produce a can of corn o 2 100 calories of fuel are used to produce a diet soda 500 for the soda 1600 for the can o solution eat food that is less processed Large Scale Meat Production o Manure results in soil and water pollution o Animal are fed grain 1 5 of all cropland in the US is used to produce grain for live stock more than for people takes eight pounds of grain to produce one pound of o energy intensive weight gain in a cow o greenhouse gas the amount of pollution produced by a cow is comparable to that by a car in a day o solution eat less meat if eating meat find a locally sustainably raised grass red option water bottles energy efficient dishwashers only running full one Reduce Reuse Recycle reusable grocery bags pans dishes rather than disposables extreme oil ma replace dwindling supplies but it comes at a heavy cost to economy and environment The future of oil Oil and foods Peak oil in the phenomenon were by global oil supplies will peak then decline with extraction growing increainly in cost 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 Adaptations of food systems for peak oil era Reduce oil in food production Increases food system energy effiency and renewable energy Change food consumption patter low oil foods Reduce food transportation distance Renewable energy glucose ethanol fuel Is there a road ahread for biofuels Technology x3 Carbohydrate fuel Dreams goals to crack the cellulose and lignin that make grasses cornstalks and wood chips into ethanol instead of using corn kernel Alternative energy Algae Biofuel Why algae o Grow rapidly turn carbon dioxide and sunlight into oil o Not picky about
View Full Document
Unlocking...