Bio-Chemistry

Energy and Metabolism Metabolism- sum of all the chemical activities taking place in an organism. Two types: anabolism and catabolism –Anabolism: complex molecules are synthesized from simpler substances Ex. Linking amino acids to form proteins Endergonic and requires ATP or some other energy source to drive them –Ex. Dehydration synthesis Endergonic reactions are exothermic reactions (energy released) –PE of products is less than the PE of reactants Activation energy

Catabolism- releases energy by splitting complex molecules into smaller molecules –Ex. Polysaccharides  monosaccharides Exergonic reaction: releases energy, from higher to lower free energy –Ex. Hydrolysis A chemical reaction would be endothermic if the amount of free energy of the products is less than that of the reactants

Protein structures Primary Secondary Tertiary Quaternary

Proteins Actin- the protein of which microfilaments consist. Actin, together with protein myosin, is responsible for muscle contraction –Actin filaments- thin filaments Myosin Insulin Pepsin Aquaporins ATP synthase Hemoglobins

Enzymes Biological catalysts Proteins, RNA, and ribozymes Increase rate of reaction Do not enter reaction Reduce activation energy Required for most biological reactions Substrate- reactant which binds to enzyme, enzyme-substrate complex = temporary Product- end result of reaction Active site – enzyme’s catalytic site Induced- fit model Enzymes have allosteric sites to which an allosteric regulator binds, changing the enzyme’s activity. –Feedback inhibition –Reversible inhibition- noncompetitive and competitive –Irreversible inhibition Enzymes are specific Enzymes have an optimal temperature and pH Enzymes require cofactors: coenzyme A Enzymes lowers a reaction’s activation energy

Water Properties Water has adhesion/ cohesion properties –Transpiration-pull cohesion tension –Capillary action –Surface tension Water has high specific heat/ high heat of vaporization Water is the universal solvent Ice floats because it is less dense than water –Spring overturn

Isomers: Same molecular formula but different structures Isotopes: are atom of one element varies in the number of neutrons in the nucleus –All isotopes are chemically identical because they have the number of electrons