MCB 3020 Lecture Notes - Lecture 2: Pseudopeptidoglycan, Micrometer, Nuclear Membrane
Document Summary
Over course of evolution, whole planet cooled down to form clouds and rain. Surface is cool but core is hot and full of magma- earthquakes and volcanic activity produce land masses. Life started when planet was covered with water in a liquid environment. First form of life was rna molecule; some rna has enzymatic activity. Need genetic material and some molecules that perform tasks- enzymes make reactions occur so acts as basis of life. First prokaryotes originated, then other two domains formed. Microbes defined as entities that cannot be seen by the naked eye- requires magnification. Made of cells- cells are unit of life. All cells made of same polymers: proteins, polysaccharides, nucleic acids, lipids. Viruses and prions are acellular- do not conform to the cell hallmarks. Viruses cannot self-replicate or have chemical control, sometimes have rna: have protein and rna or dna. Virioids made of rna and act as plant pathogens.