Adv Nutr Exam 1

• Nutritional genomics is a field that explores interactions between bioactive compounds in foods and the genome.
• Nutrigenetics focuses on bioactive nutrient interaction with genes, and gene variants.
• Nutrigenomics examines how nutrients influence gene activities, and how genes in turn influence human metabolism.
• Nutritional epigenetics focuses on alteration of gene expression (up and down regulation) of genes, which is unrelated to changes in in DNA nucleotide sequence.
• Genetic polymorphism is the reason people react differently to drugs treatment.
• The human genome project has generated significant information about genetic polymorphism.
• Genes contain information which are translated into amino acid sequence of proteins.
• A single gene mutation can result in the failure of an enzyme, leading to disease associated with the dysfunctional enzymes.
• Chromosomes are threadlike DNA molecules with part or all of the genetic material of an organism, with a p-arm being the short and q-arm being the long.
• Genes are distinct sequence of nucleotides that make up portions of a chromosome.
• Nucleotides code for specific proteins and therefore determine traits.
• There are 23 pairs in human cells (46 total), a pair of sex chromosomes (X, Y) and 22 pairs of autosomal chromosomes.
• A person inherits 23 genes from each parent.
• An inherited gene is called an Allele.
• When the inherited alleles are similar, they are said to be homozygous but if they are different, they are heterozygous.
• Alleles regulate gene expression and therefore traits that are controlled by the genes.
• Inherited genes are classified as autosomal dominant or recessive.
• The other classification is linked to X or Y chromosome.
• Dominant alleles express phenotypically when present (brown eye color vs blue).
• There are situations where two dominant alleles present (codominant).
• Main structures of the Digestive Tract & the Digestive Process include the Oral cavity, Esophagus, Stomach, Small & large intestines, and Accessory organs such as the Pancreas, Liver, and Gallbladder.
• The peptide hormone insulin has a gene that codes for its production, known as INS gene.
• Enzymes in saliva are 99.5% water and are produced by the Parotid, Submandibular, and Sublingual glands.
• α-melanocyte stimulating hormone and corticotropin-releasing hormone are other appetite suppressing peptides.
• Leptin is a peptide from white adipose tissue in proportion to fat store.
• Neuropeptide Y and agouti-related protein are other appetite enhancers.
• Ghrelin is a peptide released by endocrine cells of the stomach and it influences the hypothalamus.
• Insulin has key roles in glucose and lipid metabolism in mammals.
• Diabetes is the pathology of the absence of insulin or functionally impaired insulin.
• Lingual lipase, a serous gland on the tongue and rear part of the mouth, has activity that extends to the stomach and hydrolyzes triacylglycerol (TAG or TG).
• Lingual lipase activity diminishes with age.
• Changes in DNA can occur in many ways: Change in nucleotide sequence, Frameshift – coding vs noncoding section, Deletion, Insertion.
• Secretions of the Digestive System include Mucus, which acts as a lubricant food and coats oral mucosa.
• These changes are common causes of genetic disorders with health and nutrition implications.
• Antimicrobial agents in the Digestive System include IgA and Lysozyme, which destroy microbes.
• Some changes are benign; does not result in disease or increased risk for disease.
• R-protein binds to and protects intrinsic factor in the stomach, thus enhancing binding of cyanocobalamin (vit B12).
• Bicarbonate in the Digestive System neutralizes acidic foods and keeps saliva pH neutral.
• The sickle cell anemia mutation is a single nucleotide substitution (A for T) in the codon (G A G) for amino acid 6 (Glutamic acid).
• Phenylketonuria (PKU) is a disorder where Arginine is replaced by tryptophan in the nucleotide sequence, resulting in a defective phenylalanine hydroxylase enzyme.