BIOL107 Lecture Notes - Lecture 4: Plasmolysis, Microfibril, Cell Wall

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL107
• Professor: Carla Craveriro

Document Summary

Algae, prokaryotes and plants live in hypotonic environments. Require protection because of high internal concentration of nutrients. Note: cell wall does not protect against hypertonic conditions -> plasmolysis. Structurally ornate but simple compared with bacterial cell walls. Most common component is chitin: major component of the cell wall. Forms a microfibril in a polysaccharide matrix. If they disappear, prospects for any other life surviving would be fim. Prokaryotes thrive almost everywhere, including places too acidic, salty, cold , or hot for most organisms. What they lack in size they make up in numbers. There are more prokaryotes in handful of fertile soil than number have ever lived. Prokaryotes are divided into two domains: bacteria, archaea. Nearly all prokaryotic cells have a cell wall. Many antibiotics target peptidoglycan and damage bacterial cell walls. Gram negative bacteria are more likely to be antibiotic resistant. Capsules: a polysaccharide or protein layer that convers many prokaryotes: The capsule helps deter phagocytosis by animal cells.