Nutrients and Gene Regulation Genome Strands of DNA Contains all genetic information for the body housed in cell nucleus and mitochondria Gene the DNA sequences in the genome that are expressed in the form of protein or RNA Not all DNA sequences in the genome are expressed RNA Products of genes mRNA intermediates between genes and proteins tRNA carries amino acids DNA vs RNA Structural differences Ribose but not deoxyribose Uracil replaces thymine Gene Expression Transcription DNA mRNA Translation mRNA protein Nuclear DNA makes mRNA copy mRNA leaves nucleus DNA stays behind mRNA attaches to ribosome tRNA has been collecting AA from cytoplasm tRNA s give up their AA to the ribosome and are arranged following the map of the mRNA An enzyme then bonds with one AA to the next The protein is then released How is Nutrition Related to Genetics Vitamins work at the genetic level to turn gene expression on or off Nutrients can cause damage at genetic level or protect the body from damage at the cellular level antioxidants Defects in genetic code cause nutrition related diseases mutations Cystic fibrosis defect in a gene that codes for chloride channels throughout the body which causes excess mucus production failure to produce digestive enzymes and thus malabsorption Phenylketonuria PKU inborn error of metabolism a genetic disorder with mutations in a gene that metabolites phenylalanine buildup results in brain damage Sickle Cell Anemia normal RBC are sickle shaped one amino acid off resulting the RBC to change shape and lose function Nutrients Involved in Gene Expression Selenium Deficiency results in selenoprotein mRNA degradation Iron Effects mRNA translation of proteins involved in iron absorption When iron is high mRNA of an iron storage protein undergoes translation When iron is low mRNA of an iron storage protein is blocked from translation Vitamin D Calcium Some amino acids phenylalanine Nutrigenomics The study of how naturally occurring chemicals in foods alter molecular expression of genetics informal in each individual Identification and understanding of population differences and similarities in gene expression or phenotype in response to diet Significance Early detection may aid with prevention or may cause undue worry Identification of specific genes may better focus treatment Can use as better assessment of nutritional status Use to set RDAs more accurately Epigenetics 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 4 bases Modifications on the histone proteins acetylation on histone
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