CMMB 343 Final Exam Actual Questions and Answers with complete solution

CMMB 343 Final Exam Actual Questions and Answers with complete solution Define 1.Microhabitats 2.Microbiota 3.Microbiome - answerMicrohabitats: specific areas where they grow Vary in physical characteristics. Each microhabitat is not homologous- differences within the same microhabitat- armpit vs toe Microbiota: describes all the microbes in a microhabitat Microbiome: entire collection of microbes living in all of the microhabitats Which organism (gram - or +) dominates the 1. the human microbe 2. GI tract - answer1. Gram + 2. Gram - What does the human microbiota influence? - answerDevelopment of microbiome will influence physical development- presence or absence of certain organisms will change the way you develop as an individual Influences our health What two organisms dominate the GI tract - answerBacteroidetes(gram -) and Firmicutes (gram +) Explain the environmental differences as you move along GI tract in terms of pH, oxygen content, and organism diversity - answerIncreasingly anaerobic + neutral pH At top pH of 2 in stomach going to neutral pH in small intestine . Diversity of organisms increases as pH becomes neutral an oxygen levels become anaerobic What type of culture system does the colon resemble - answerA continuous system (we shed cells and replace them) What do the organisms in our GI tract do? - answer-These bacteria help us digest complex carbs + synthesize essential nutrients like a.a and vitamins -Chemical modification of bile so it can be reabsorbed -Protects us from pathogens (microbial warfare) -Immune system development- trains our immune system to recognize normal from potentially pathogenic bacteria How do microorganisms affect fetal development? - answerFetus is sterile→ after birth, colonization begins with feeding and contact Babies born naturally vs c section have diff microbiota Breast milk has sugars that mammals cant digest but bacteria can Metabolic waste products of microbial fermentation can communicate with our immune to display normal conditions What are MAMPs and what is their purpose? - answerMAMPs: microbe-associated molecular patterns Exposure to MAMPs is crucial to neonatal gut maturation and immune system development Insufficient exposure to MAMPs can result in reduced colonization resistance and susceptibility to immune mediated disease like IBS What are the 3 important short chain fatty acids produced by fermentation? - answerButyrate Propionate Acetate What is IBD and how does it develop? - answerResult of improper development in infancy and massive changes to diet and lifestyle Pathogenic species gain access to the gut epithelium altering normal function -Immune system response inflammatory response -Immune system learns to view normal bacteria as pathogenic -Gut becomes more aerobic which further facilitates growth of pathogens What is the difference between the microbiota of obese and lean animals? - answerObese animals have v diff GI microbiota from lean animals Obese: fewer Bacteroidetes more firmicutes, and way more methanogens High fat/ low fiber→ obese Low fat/ high fiber→ lean Methanogens: Remove H2 which favours growth of firmicutes Firmicutes generate more SCFAs for host → too many nutrients Bacteroidetes inhibit host metabolism and triglyceride storage What is the difference between firmicutes and bacteroidetes in terms of impact on human health? - answerFirmicutes generate more SCFAs for host → too many nutrients Bacteroidetes inhibit host metabolism and triglyceride storage More firmicutes= obesity more bacteroidetes= lean What are the 5 ways to alter microbiome? - answerAntibiotics will affect normal GI microbiota -disruption can allow colonization of antibiotic resistant pathogens Fecal Transplants Introduce healthy microbiota to GI dysbiosis The healthy hopefully compete with p