Topic 2.1 Molecules to Metabolism

Urea & Falsification of Vitalism Vitalism – theory the origin and phenomena of life are due to a vital principle, which is different from chemical or physical forces.  Organic compounds could only be made with the help of a “vital principle”

 1872 Urea synthesized artificially – first organic compound  NO Vital Principle involved  Evidence against theory of vitalism Scientist accept that processes in living organisms are governed by same chemical and physical forces as in non- living matter Hemoglobin still not able to be synthesized in lab

Urea  Nitrogen-containing compound w/ simple structure  Component of urine  Naturally produced when excess of amino acids in body, to remove nitrogen  Chemical reactions in liver, catalyzed by enzymes produce Urea  Transported to kidneys  urine  Artificially ammonia + carbon dioxide  ammonium carbamate  urea + water  100 million tons produced annually. Nitrogen fertilizer

carbon  15 th most abundant element on earth  Forms up to 4 covalent bonds with other atoms, allowing for complex structures  Forms single, double & triple bonds C

Carbohydrates Carbon, hydrogen & oxygen 2 Hydrogen:1 Oxygen Lipids Insoluble in water Steroids, waxes, fatty acids, triglycerides Triglycerides: fats if solid at room temp, oils if liquid

Proteins One or more chains of amino acids All amino acids contain carbon, hydrogen, oxygen & nitrogen 20 amino acids contain sulfer Nucleic acids Chains of nucleotides Nucleotides contain carbon, hydrogen, oxygen, nitrogen and phosphorous Deoxyribonucleic acid Ribonucleic acid

Functional groups Methyl Group Hydroxyl Group Amino Group Carboxyl Group Aldehyde Group Ketone Group

Ribose  C 5 H 10 O 5  5-membered ring with side chain  4 carbon atoms in ring, one in side chain  Carbons numbered starting with number 1 on right  Hydroxyl groups (OH) on carbons 1, 2 & 3 point up, down, and down respectively

Glucose  C 6 H 12 O 6  Six-membered ring with side chain  5 carbons in ring, one in side chain  Carbons numbered starting with 1 on right  Hydroxyl group (OH) on carbons 1, 2, 3, 4 point down, down, up and down  *** glucose in plants making cellulose: hydroxyl points up.

Saturated Fatty Acids  Carbon atoms form an unbranched chain  Saturated acids contain only single bonds  Usually between carbon atoms  Carboxyl group at one end of chain  3-hydrogen atoms at other end  All middle carbons bonded to 2 hydrogen atoms

Amino Acids  Carbon in center of molecule, bonded to 4 different things  An amine group  A carboxyl group  A hydrogen atom  The R group, which is variable

Identifying molecules  Proteins contain C, H, O and N  Many proteins contain sulfur. Carbohydrates and lipids don’t.  Carbohydrates contain C, H, O, but No N  Carbohydrates contain hydrogen and oxygen in 2:1 ration  Lipids contain less oxygen than carbohydrates

Metabolism  The sum of all enzyme-catalysed reactions in a cell or organism.  A metabolic pathway is either a chain of events, each catalysed by an enzyme, or a cycle of reaction. DCDTG6XI/AAAAAAAAANM/JJ1JZ-ub7JU/s1600/krebs-cycle.jpg

Anabolism vs. Catabolism  Synthesis of complex molecules from simpler ones  Monomers  macromolecules (amino acids  protein)  Condensation reactions where water is produced  Example: ? Breakdown of complex molecules to simpler ones Macromolecules  monomers (protein  amino acid) Hydrolysis reactions where water is consumed Example: ? alternatives.jpg

examples AnabolismCatabolism  Protein synthesis in ribosomes*Digestion of food  DNA synthesis *Cell respiraton  Photosynthesis*Digestion of complex carbon compounds  Synthesis of complex carbohydrates in dead organic matter by decomposers including starch, cellulose & glycogen