Zoology 101: Animal BiologyLast Lecture Outline Lecture 6 1.Simple Diffusion2.Facilitated diffusion• Channel Proteins• Carrier proteins3. Osmosis4. Active Transport5. Vesicular (Bulk Transport)Current Outline1. Prokaryotic Cell Structure• Human Microbiome 2. Intestinal Gut Microbiome• Mice3. Development (Structure)4. Protective Function• Quorem SensingProkaryotic Cell Structure• Plasma membrane, cystol, chromosome (usually circular, in nucleoid region), cell wall (contains peptidoglycan), flagellum (movement of cell), ribosomes (site of protein synthesis)• Human Microbiome: all micro-organisms that live in and on us (fungi, protazoan, archea, bacteria)◦ very vast◦ diverse◦ commensal: one organism benefits while the other has no effect (nonpathogenic bacteria)• Human Microbiome Project: sequence DNA from all microbe species living in/on body◦ difficult to study▪ Abundance ▪ anerobic intestinal microbiome◦ 16s ribosomal RNA gene◦ What have we found out?▪ Start accumulating microbiome at birth▪ No two people share the same microbiome▪ most people share a core complement of commensals▪ important in human health and disease ▪ Long way to goIntestinal Gut Microbiome• metabolic functions: Vitamin synthesis, fermentation (digestion), absorption of nutrients • Structural functions: development of digestive system• protective function: competitive with pathogens • 4 predominate species • Mouse is a model organism: non human species used to understand biological phenomena with expectation that discovers will provide insight in to workings of other organisms◦ Share common ancestor◦ learn in mice: the ratio of bacteriodetes to firmicules leads to weight gain ◦ Hypothesis: bacteria from phylum Firmicutes plays key role in promoting absorption of fat from food◦ microbes can promote absorption of dietary fats in ingestion and their subsequent can be metabolizedDevelopment (Structure)• Hypothesis: bacteria presiding in intestine shape gut developmental• Experiment◦ sterile environment lead to abnormal gut and function◦ general microbial factor influences gut structure in zebra fishProtective Function• c. Difficle infection: injection of fecal matter → competition good bacteria keeps bad bacteria in check• We use antibiotics to kill or inhibit growth of bacteria◦ antibiotics aren't selective; kills all bacteria • long term changes◦ fear we might overuse antibiotics → long term change to microbiome, increase in infections/disease • Quorem sensing: system of stimulus and response correlated to population density• in squid:◦ Low cell density= no light◦ high cell density= lots of signaling in molecule • Disease causing bacteria have quorem sensing molecule: at a high density they become virulent (disease causing); binds to receptor, disease causing genes turn on • Anti-quorem sensing molecule◦ species specific ◦ virulence cannot bind to receptor; stopping
View Full Document