PHLT 304 TAMU Test One Questions With Verified Answers

Public Health Triad - Answer host factors, environmental factors, agents (people, other species, environment) Anthropogenic pollution - Answer caused by humans; most of what people consider pollution; lead, carbon monoxide, ozone, particulate matter, SO2, etc. soil -- microbes, pesticides, mining, slash and burn Naturally-Occurring pollution - Answer volcanoes, soil deposits, natural seepage, fires Bioaccumulation - Answer accumulation of a toxic chemical in the tissue of a particular organism; occurs when the chemical is absorbed somehow from the environment, and not eliminated well from the body, so it tends to accumulate in the body Biomagnification - Answer increased concentration of a toxic chemical the higher an animal is on the food chain; occurs when the chemical is ingested in food, and the chemical is not eliminated well from the body; when this occurs, you will see increasing concentrations in body tissues as you go up the food chain How can climate change influence human disease? - Answer extreme weather; food and water scarcity, emerging disease -- dengue and chikungunya, malaria, chagas, tick borne diseases Zoonosis - Answer humans get diseases from animals; examples are plague, tuberculosis, lyme disease, WNV Cross-species transmission - Answer transfer of disease between animal species Anthropozoonosis - Answer when animals get diseases from humans; particularly an issue with primates Interconnectedness of ecological systems and humans - Answer *** Proteins - Answer enzymes: active site and competition important subset -- drug-metabolizing enzymes Carbohydrates - Answer simple sugars and complex starches Lipids - Answer fats, oils, waxes; compound: phospholipids and glycolipids; derived: steroids and carotenoids Nucleic acids - Answer RNA, DNA, central dogma Central Dogma - Answer DNA-transcription-RNA-translation-protein Plasma (cell) membrane - Answer structure is lipid based and contains proteins; selective barrier; controls movement in and out of cell Nucleus - Answer largest single organized unit in cell; storage of genetic material (DNA and RNA) Cytoplasm - Answer location: portion of cell not occupied by the nucleus; composition: cytosol... organelles are dispersed within Endoplasmic reticulum - Answer network of fluid-filled tubules and flattened sacs; contains smooth ER and rough ER; protein synthesis and transportation of materials through cell Golgi complex - Answer "raw" proteins modified to final form; modified proteins are sorted and distributed Lysosomes - Answer digest and eliminate cellular waste Peroxisomes - Answer detoxify cells Mitochondria - Answer derive energy from ingested nutrients; site for production of ATP Enzyme - Answer greatly accelerate reactions; highly specific in reactions and substrates; generally catalyze a single reaction or set of closely related reactions Drug-metabolizing enzyme - Answer *** DNA adducts - Answer benzopyrene undergoes metabolism to a reactive compound that binds to DNA to form a DNA adduct; adducts can cause the formation of mutations in DNA and cause cancer Protein adducts - Answer product of covalent bonding between a chemical (ex. carcinogen) and a biological macromolecule (DNA, protein) Mutagens - Answer A chemical or physical agent that interacts with DNA and causes a mutation Carcinogens - Answer Cancer-causing agents Teratogens - Answer agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm Potential stages in the development of toxicity after chemical exposure - Answer toxicant > delivery > interaction with target molecule OR alteration of biological environment > cellular dysfunction, injury > TOXICITY Alteration of biological environment - Answer like kidney stones; hard deposits of minerals and salts that form in the kidney; often form when urine becomes concentrated >> minerals crystalize Interaction with biological environment - Answer like benzo(a)pyrene; produced by burning; found in smoke; produces cancer in lab animals; considered a human carcinogen Mutations - Answer in genes produce changes in proteins that may be detrimental; most mutations are silent and not all are bad; introns and exons explain for silent mutations DNA structure in cell nucleus - Answer each chromosome contains one double-stranded piece of DNA that is coiled at several levels; DNA is wrapped around a histone protein core to form a nucleosome; DNA is coiled further into solenoids (each turn of the solenoid has about 6 nucleosomes); solenoids are organized into chromatin loops; each loops has about 100,000 base pairs of DNA Dominant and recessive alleles - Answer homozygous, heterozygous, hemizygous Single nucleotide polymorphism - Answer many are found in regions of DNA between genes; some are found in regions that affect specific genes; SNPs can influence response to a drug or susceptibility to an infectious agent or environmental toxicant; SNPs are much more common in the population and have lower correlation to phenotype than Mendelian-type mutations Gene-environment interaction - Answer situation in which the effects of genes depend on the environment in which they are expressed CY2PD6 metabolizing enzyme - Answer metabolizes 20-25% of common prescription drugs; caucasians: divided in poor (5-10%), extensive (90%), and ultra extensive (1-2%) metabolizers Response to alcoholic drinks - Answer the enzyme alcohol dehydrogenase (ADH) concerts ethanol to acetaldehyde (toxic); the enzyme aldehyde dehydrogenase (ALDH) oxidized aldehydes to acetate (less toxic); acetate is then broken down to carbon dioxide and water; approximately 50% of Chinese, Koreans, Taiwanese, and Vietnamese populations have high incidence of atypical form of ADH (rapid buildup of acetaldehyde and flushing, dilation of blood vessels in face) Epigenetics - Answer impacts gene expression without changing DNA sequence; changing phenotype but not genotype; epigenetic factors are changeable and differ by tissue and disease state; can be passed to future generations Mechanisms of epigenetic modification - Answer DNA methylation: when close to a gene, often reduces expression of that gene; can be reversed with demethylation Mechanisms of epigenetic modification - Answer histone tail modifications; usually associated with transcriptional activation bc this decreases the affinity of histone proteins for DNA, leading to relaxation of chromatin packaging