PUBH 6011 FINAL EXAM LATEST 2022|2023|2024 REAL EXAM QUESTIONS AND ANSWERS/PUBH 6011 FINAL STUDY GUIDE | A GRADED.

PUBH 6011 FINAL EXAM LATEST 2022|2023|2024 REAL EXAM QUESTIONS AND ANSWERS/PUBH 6011 FINAL STUDY GUIDE | A GRADED. Disease and the Environment • Understand the major functions of cells and the difference between viruses, bacteria Viruses are either naked or enveloped. Enveloped can be easily disrupted with alcohols but naked are more stable. Bacteria has different states of living. Some are free to flow while others stack up and create biofilm making them resistant • Explain protein synthesis and the role of DNA, mRNA, tRNA, ribosomes DNA is found within the chromosomes which are found in the nucleus of a cell. DNA has a nucleotide component (adenine, guanine, cytosine, thymine), phosphate group, and sugar. DNA carries the coding sequence is the template for messenger RNA (mRNA). Transfer RNA then links the amino acids which will form that specific protein by using units within ribosomes. 1) DNA is transcribed to messenger RNA via enzyme DNA Polymerase. 2) The mRNA is then spliced and the introns are then 3) Transfer RNA brings amino acids to the ribosome and creates a chain of amino acids coded bu the mRNA. Once the chain is complete it is released and folded into protein. • Explain how biological and genetic factors can influence our response to environmental hazards • Explain the role of the microbiome and its role in disease prevention • Explain how environmental factors influence genetic expression (i.e., epigenetics) Epigenetics determine which genes are expressed (turned on or off) Results in a heritable change in the phenotype without changes in the DNA sequence It is said that ways in which our bodies express genetic information can be influenced by the world around us. 3 mechanisms of epigenetics - DNA methylation- helps in discovering air pollution sensitivities can be inherited - Histone modification- acetyl group binds to histone causing DNA to unwind and begin transcription - Micro- RNA and non-coding RNA- studied in cancer • Explain various types of genetic mutations that can occur Microlesions - Base-pair substitution can happen via alkylating agents, ionizing radiation, or spontaneously - Point mutation o Silent- change in base pair but codon still codes for same amino acid o Nonsense- STOP codon o Missense- change in amino acid could be conservative which is a similar structure to orginal or non-conservative which is a very different structure - Frameshift mutation- changes the reading frame via insertion or deletion of one or more base which can lead to altered proteins and often nonfunctional proteins - Chromosome Aberrations- change in chromosome structure often found in change of chromosome number o Aneuploidy- increase in number of one or more  Often caused by nondisjunction in meiosis o Polyploidy- increase in whole set of chromosomes - Human Variability o Polymorphism- variation in DNA sequence between individuals o Single neucleotide polymorphism- single base pair changes present in the population at a rate greater than 1 % o • Explain the difference between genotoxic versus non-genotoxic carcinogens (i.e., initiator/promoter) Genotxic carcinogens are also called mutagens and are able to DIRECTLY or with metabolic activation alter DNA via pint mutations or chromosomal aberrations - Non-genotoxic compounds do not directly alter DNA but may increase cancer risk by increased risk of replication errors or increasing the number of cells at risk • Know the three cancer types in the US that cause the highest mortality • Explain the difference between innate versus adaptive immunity Innate immunity helps in protection against foreign things in the body it is prepared to protect whatever. A • Explain the antibody/antigen reactions and the types of defense reactions they trigger • Explain how vaccines use the body’s natural immune system to protect from diseases • Explain the importance of “herd immunity” in protecting a population from the spread of disease. Toxicology and Risk Assessment Explain the biological mechanism of digestion and the first pass effect Digestion starts with mouth (mechanical) Moves down the esophagus via contraction and relaxing to move food down into the stomach (peristalsis). In the stomach food is churned and more enzymes are added to break down the food. After stomach is goes to small intestines where more enzymes, bile, and hormones are added to digest food further and start process of absorption of nutrients into the bloodstream. The absorbed by villi and microvilli which increases the surface area of the small intestine. Nutrients absorbed into circulatory system and delivered to appropriate organs. Waste is also transferred to the circulatory system to be excreted. Large intestine absorbs excess water from undigested food. Absorption: influenced by membrane barrier. Uncharged (hydrophobic) can cross while polar (charged) are not able to cross. Protein channels and pores facilitate absorption of chemicals which normally would not be readily absorbed. FIRST PASS EFFECT: everything absorbed by through digestion ing GI tracts must first go through the liver. - Gases pass readily - Glucose cannot (uncharged but too big) Facilitated diffusion - Ions and charged polar molecules cannot pass - Active transport is used to go the opposite direction (low to high) by using ATP as source of energy • Explain the role of liver in breaking down food, microbes and chemical toxicants Absorbed from intestinal tract, then portal circulation brings directly to the liver • Explain how different people may handle toxicants differently based on enzymatic makeup PUBH 6011 LAPUMA 8 There is variability in metabolism. Identifiable metabolizers vary across ethnic groups. Depending on exposure the rate of metabolism may greatly influence either the benefit or detriment to come from metabolic steps. Chemical can either become more or less toxic.