BIOL 1201 Lecture : Lecture 4
Document Summary
Energy = the capacity to do work: kinetic energy = energy of movement. 1st law: conservation of energy: amount of energy in a system remains constant. 2nd law: when converted from one form to another, useful energy decreases. Photoautotrophs (plants, other producers) create their own food. Heterotrophs (consumers, decomposers) must find their own food. How does energy flow in chemical reactions: chemical reaction: forming and breaking chemical bonds among atoms, reactants: starting materials, products: result of the reaction. Exergonic reactions: high energy reactants (a + b) Energy is released : low energy products (c + d) Endergonic reactions: low energy reactant, high energy products. Exergonic reaction: atp 100 unites energy released + adp + p. Endergonic reaction: relaxed muscle + 20 units energy contracted muscle. Coupled reaction: relaxed muscle+ atp contracted muscle + 80 units energy****** Coupled reactions within living cells: glucose co2 = h2o + heat exergonic (glucose breakdown)
