VIBS 422 EXAM 2 2024 Questions with 100% Solved Solutions

What are plasticizers? - Plasticizers are additives that are incorporated into a material to increase its flexibility by weakening the bonds so the polymer chains can move more freely relative to one another and polymer becomes less stiff. The two most common plasticizers used today in PVC are? - DEHP and DINP What is the chemical name of Phthalate? - 1,2-benzene-dicarboxylic acid What are the physical properties of DINP? - superior anti heat, anti-cold, and antivolatile properties What are the physical properties of DIDP? - low volatile properties, anti-heat and anti-aging (for the product) properties and low insulation properties River that was cleaned up and then recontaminated with phthalates from storm water runoff? - Duwamish River Commencement Bay - $103 million superfund cleanup -phthalate recontamination ongoing How can we be exposed to phthalates? - -inhalation: phthalates erode off of products & contaminate air -ingestion: drinking polluted water due to plastics -absorption: contact with plastics that are made of DEHP -medical procedures: fluids and drugs in plastic bags, dialysis tubing, heart bypass surgery, and blood transfusion products -Work related: jobs that create a lot of contact with DEHP -Food: baked goods, highest levels found in milk and cheese -cosmetics, perfumes List any 5 toxic effects of phthalates in females? - -elevated serum estradiol levels -advanced onset of puberty -increased ovarian and uterine weights -uterine malformations -reduced fecundity What are 4 major symptoms of Phthalates Syndrome? - -leydig cell abnormalities -dysgenesis of leydig cells and seminiferous tubules -undescended testes -spermatogenic failure and infertility Describe toxic effects of phthalates on male reproductive function - -decrease in anogenital distance (AGD) -disrupts testicular descent and development of a small and indistinct scrotum -DEHP disrupts and decreases spermatogenesis and lowers the intra-testicular and plasma testosterone levels by directly acting on leydig cells What was the agent used in Vietnam? - Agent Orange What is the toxin in Agent Orange - TCDD Phthalate metabolism: DEHP is oxidized to form MEHP; MEHP is metabolized by different oxidation reactions. - TRUE The symptoms of phthalate syndrome are leydig cell abnormalities, undescended testes, and spermatogenesis failure - TRUE Who discovered the first DDT in 1939? - Paul Muller Which is not a most common 2nd gen pesticide? - BPA What 4 crops account for 70% of insecticides in US? - corn, cotton, wheat, soy beans (T/F) DDT is excreted in urine, feces, or breast milk. - true ID this EDC: - phthalate What EDC is a nonsteroidal estrogen given to women to avoid pregnancy complications? - DES How is DES eliminated from the body? - through the biliary excretion in feces (T/F) DES binds to androgen receptors. - false What is the half life of DES? - primarily 3-5 hours; 2-3 days due to entero-hepatic recirculation (T/F) Microplastics cannot cross the cell membrane. - false What is the common way that microplastics interact with marine biota? - Ingestion What are the effects on the 3rd generation of children of mother's exposed to DES? - -epigenetic changes -males have hypospadias -females have increased risk of infertility and ovarian cancer What are phytoestrogens? - plant-derived xenoestrogens that function as female sex hormone (T/F) Phytoestrogens can activate or block estrogen receptors - true What is the phytoestrogen found in soybeans? - genistein (T/F) Genistein causes disrupted ovarian function and decreased pituitary responsiveness of LH in response to GnRH - true Which EDC causes multi-oocyte follicles? - Genistein (T/F) Phytoestrogens cannot pass through the cell membrane because of their low molecular weight and stable structure. - false List 4 gender-benders that are used in day to day life: - -parabens (cosmetics, creams, lotions) -triclosan (antibacterial soap, toothpaste) -bisphenol a (mobile phone casings, baby bottles) -procymidone (fruit smoothies, breakfast cereal) What does the addition of plasticizers do? - causes reduction in cohesive intramolecular forces -stiffness of polymer reduced