MCB lecture 1 GO ILLINOIS EDU 150FAQ 08 26 2013 Lecture 2 08 26 2013 The Linnaen system of classification originated in the 1700s and was based on physical characteristics Does it make its own food Does it move Technology eventually advanced to the point where we could examine the contents of individual cells Two basic types of cells were seen o Those with a kernel Karyon nucleus eukaryotes o Those without a kernel prokaryotes A typical prokaryotic cell Cell wall usually but not always Cytoplasmic membrane o Serves role of cytoplasmic membrane and other internal membranes in eukaryotes Nucleoid usually a single chromosome not surround by a membrane A typical eukaryotic cell animal cell unlike plants does not have cell wall and chloroplasts Inside of cell separated into distinct into distinct compartments called organelles Until 1977 organisms were thought to fall into 2 super kingdoms Prokaryotes without a nuclear membrane and membrane bound organelles Eukaryotes with a nuclear membrane and membrane bound organelles Physical structural characteristics are useful for crude classifications Carl Woese and co workers here at Illinois compared the sequences in the different species of molecules ssrRNA which are an essential component of every cell s machinery for synthesizing proteins The more different the rna they are less related more similar closely related Why RNA o Evolutionarily ancient one of the first something we can watch over a long period of time to change o Found in all organisms o Highly conserved sequences very similar evolved slowly Conclusion prokaryotes are actually two distinct groups of organisms o Eu bacteria true bacteria like E Coli found everywhere o Archaea ancient prokaryotes first discovered in extreme habitats that resemble early earth Now we see they live in non hostile environments That conclusion was based on the observation that archeal rRNA sequences are more closely related to eukaryotic rRNA sequences than to bacteria Revised tree of life with 3 domains rather than 2 super kingdoms Despite physically resembling bacteria they are both prokaryotes in most molecular processes archaea are more similar to humans than to e coli When Woese first did his work very few genome sequences were available as of today 6 880 complete genomes sequenced with another 21 053 genomes in progress Other genes have been analyzed using comparative methods Trees drawn from these data differ slightly Not as simple as once though Actually a web of life Involves horizontal gene transfer No two species are indentical structurally and biochemically but they are all made of one or more cells why Needs to be organized living compartment cell Basic tenets of the CELL THEORY Cells are the fundamental units of life All organisms are composed of one or more cells All cells come from preexisting cells Why are cells small As the size increases the surface area to volume ratio decreases Lecture 3 08 26 2013 Basic Structure of the Eukaryotic Cell Intro to Carbohydrates A typical eukaryotic animal cell Plasma Membrane separates extracellular space and cytoplasm Nucleus command and control center o Replicate and maintain our genomes o Distribution of the genetic information transcription o DNA storage o Put ribosomal subunits in the nucleus assemble large and small subunits nucleolus o Nuclear envelope two lipid bilayer Mitochondria provide energy make atp Rough Endoplasmic Reticulum ribosomes attached o Protein synthesis o Membrane of RER is continuous with the outer membrane of nucleus o pancakes Smooth Er attached to RER o Lipids made here o Detox Golgi apparatus o Physically separate than RER but intimate o Everything from RER comes here o Post office o Interprets shapes Ribosomes o Free floating in cytoplasm o Macromolecular machine not organelle o Polyribosome formation multiple ribosomes making the same copy of the same protein What composes the organelles membranes genomes etc of the cells we ve examined 4 major types of biological macromolecules o proteins o nucleic acids o carbohydrates or polysaccharides sugars o Lipids fats Approximate chemical comp of bacterial cell mostly water second most macromolecules More proteins than carbs Macromolecules Polymers are made up of monomers Polymerization bonding together monomers Proteins amino acids Nucleic Acids Nucleotides Polysaccharides monosaccharide Membrane Lipids fatty acids and glycerol Made by o Condensation or dehydration synthesis Monomer in water out o Hydrolysis water in monomer out Bean protein used for amino acids to make human protein Polysaccharides Condensation reactions bringing together monosaccharide Uses energy sources structural roles like insect exoskeletons and cell walls or cell identification and recognition chitin carbohydrate can refer either to the complex sugars polysaccharides or the simple sugars monosaccharide General formula of the carb o Cn H20 n with a backbone H C OH Standard conventions for atoms in ring structures Within the ring itself it youre not explicitly told otherwise the atom is a C Withing the ring itself if an atom is not a carbon it needs to be specified Above the ring carbons need to be specified Above or below the ring any atom that is not specifically identified is assumed to be an hydrogen Circularization of glucose alpha glucose or beta glucose If H above alpha If H below beta Some monosaccharide have identical formulas but different structuresisomers Aldehyde v ketone Aldose ketose Lecture 6 08 26 2013 Does the information for how a protein will fold lie in its primary sequence YES How could we determine this o Removal or inactivation of stabilizing forces unfold denatures the protein to 1 degree structure but no peptide bonds are broken All 2 degree and 3 degree structure is lost Almost always leads to loss of function Acids bases heat detergents Why do some proteins not fold in vitro and fold in vivo Not enzymes they take A and B into C Chaperones help proteins fold correctly Enzymes Biological catalysts they facilitate biological reactions This is necessary because most cellular reaction proceed at a very slow rate Two broad categories of cellular reaction based on Reactions that require energy are called biosynthetic or anabolic o Create covalent bonds o Linking together of smaller molecules into larger ones such as condensation reaction of monomers to macromolecules Reactions that release energy are called catabolic o Break down larger molecules into smaller ones such as the