MCB Exam 1 02 10 2014 8 30 Eukaryotic Cell Plasma membrane barrier that surrounds the cell Nucleus command and control center of cell 1 replicate and maintain our genomes where DNA stores and copies 2 distribution of that genetic information transcription and RNA processing putting ribosomal subunits together 3 nucleolus is where ribosomes are put together Mitochondria cell s energy where ATP is made Rough ER has ribosomes attached ribosomes synthesize proteins continuous of the nuclear envelope synthesize and secrete proteins inside Smooth ER no ribosomes no active protein synthesis make lipids detoxification centers harmful products get broken down Golgi associated with ER processes things from the ER and transports them sorts distributes Ribosomes macromolecular machine not an organelle reading info from RNA molecules and turning it into a protein work in teams polyribosomes make its own copy 4 major types of biological macromolecules proteins composed of amino acids nucleic acids composed of nucleotides carbohydrates composed of monosaccharides lipids composed of fatty acids macromolecules polymers are made up of monomers polymerization process that binds together monomers condensation dehydration synthesis monomer in water out covalent bond is formed hydrolysis water in monomer out Carbohydrates polysaccharides made from condensation reactions bringing together monosaccharides uses energy sources structural roles like inset exoskeletons and cell walls or cell identification and recognition can refer either to the complex sugars polysaccharides or the simple sugars monosaccharides Formula Cn H2O n with a backbone of H C OH standard conventions for atoms in ring structure within the ring itself if you re not explicitly told otherwise the atom is a Carbon C within the ring itself if an atom is not a carbon it needs to be specified above or below the ring carbons need to be specified above or below the ring any atom that is not specifically identified is assumed to be a hydrogen H monosaccharides are typically found with 3 5 or 6 carbons carbon 1 is closest to the far right moves clockwise circularization of glucose a glucose hydrogen is above the ring b glucose hydrogen is below the ring isomers identical formulas different structures hexoses 6 carbon sugars glucose galactose fructose 9 4 Carbohydrates II monosaccharides have similar not identical formulas similar structures and related functions monosaccharides are typically found with 3 5 or 6 carbons triose 3 carbon sugars linear pentose 5 carbon sugars ribose ribulose circular hexose 6 carbon sugars monosaccharides can be brought together to form a very simple polysaccharide called a disaccharide via a covalent bond called glycosidic linkage glyco something sweet sugary glucose contributing its C1 is an alpha glucose making the resulting glycosidic linkage an a 1 4 glycosidic linkage cellobiose is a disaccharide of beta glucose and another glucose connected via a B 1 4 glycosidic linkage lactose is a disaccharide of glucose and galactose sucrose is a disaccharide of glucose and fructose the chemical formula for a disaccharide of hexose sugars is C12H22O11 know what makes up disaccharides and what linkage one monomer is a monosaccharide two monomers is a disaccharide several monomers are called an oligosaccharide oligo several hundreds or thousands of monomers are a polysaccharide poly many Carbohydrates can be modified linkage of oligosaccharides to other macromolecules when covalently linked to membrane proteins or lipids carbohydrates act as identification and recognition molecules chemical markers as in blood typing carbs have to be outside to signal identify cell chemically modifying their own structure addition of chemical groups o fructose fructose 1 6 biophosphate bi not di because phosphates aren t linked covalently o Glucose amino group glucosamine galactose amino group galactosamine Polysaccharides serve as chemical sources of energy or structural compounds cellulose most abundant carbon containing compound of earth found in plant cell walls linear unbranched polymer of glucose o monomers covalently linked by B 1 4 glycosidic linkages o linear polymers held together by hydrogen bonding with neighboring strands starch found chiefly in seeds fruits tubers roots and stems of plants energy storage helical unbranched or loosely branched polymers of glucose o monomers within chains covalently linked by a 1 4 glycosidic linkages o chains branch linked a 1 6glycosidic linkage glycogen found in muscle and liver cells of animals energy storage helical highly branched polymers of glucose o monomers within chains covalently linked by a 1 4 Proteins Functions Movement actin myosin Defense Antibodies Structure keratin Transport hemoglobin Signaling glucagon Catalysis regulation metabolism amino acids are monomers of proteins c amino group carboxyl group hydrogen above carbon R group side chain R group differs 20 peptide bond formation condensation reaction linking 2 amino acids dipeptide ribosomes link amino group of incoming amino acid to the carboxyl group of the existing protein in the N C direction a few amino acids oligopeptide long chain of amino acids polypeptide Amino acid R groups differ only in R groups 20 20 2 400 possibilities for dipeptides 20 3 possibilities for tripeptides most are 100 amino acids uncharged but polar polar means partial charge electrons are pulled toward oxygen uncharged and non polar hydrophobic all hydrogen or carbons bc they have equal sharing of electrons positively charged basic negatively charged acidic Primary and Secondary Structure 3D shape conformation is critical to functioning of each protein consequence of folding improperly is significant protein structure 1 primary structure 2 secondary 3 tertiary 4 quaternary Primary linear sequence of amino acids N C all proteins have a unique primary structure secondary first level of folding stabilized by weak hydrogen bonds between peptide linkages o peptide backbone is polar independent of R groups a helix and b pleated sheets hydrogen bonds can form between nearby amino and carbonyl groups on the same polypeptide chain hair protein keratin is very rich in a helical structure o hair stretches because it is easy to break the H bonds that stabilize a helices prion misfolded proteins which somehow induce normal versions of that protein to fold the same incorrect way misfolded protein come out of solution create plaques Tertiary and Quaternary