500 bp 1300bp 200 bp 500 bp 1100bp metabolism and

This preview shows page 18 - 23 out of 36 pages.

- 500 bp - 1300bp - 200 bp - 500 bp - 1100bp METABOLISM AND ENZYMES - Review - Energy, metabolism, kinetic energy, potential energy, work - Every living thing is being powered by sunlight - Photosynthesis & Cellular Respiration - Without, there would be no life on the planet - 0.23% (approx.) of sunlight is used by photosynthesis - 1st Law of Thermodynamics - Energy cannot be created or destroyed but only converted from one form to another
- Photosynthesis - Light energy → chemical energy - 6 CO 2 (g) + 6 H 2 O(l) → C 6 H 12 O 6 (aq) + 6 O 2 (g) - Light energy in the presence of chlorophyll allows this conversion - PLANTS DON’T NEED YOU, YOU NEED THEM - Plants do their own cellular respiration, they do not require the CO 2 and H 2 O we produce through cellular respiration - Humans depend on the oxygen plants produce - Cellular Respiration - Chemical energy → chemical energy (ATP) - C 6 H 12 O 6 (aq) + 6 O 2 (g) → 6 CO 2 (g) + 6 H 2 O(l) - 36 to 38 ADP molecules → 36 to 38 ATP molecules → life processes → begins again - ATP (adenosine triphosphate) - Rechargeable battery of your cells - You may drain and refill the energy - Cellular respiration charges the battery (aka ATP) - Chemical energy is stored in the bonds of a molecule - Bond strength (kJ/mol) varies with bond type - Create a bond → energy is absorbed - Break a bond → energy is released - Enthalpy (H) - Potential Energy Diagrams - Change in potential energy during a chemical reaction - Activation energy: energy required to break reactants’ bonds - Transition state: temporary state during which bonds are breaking and forming Types Exothermic Endothermic Potential Energy Diagram Energy Released Absorbed
is... Enthalpy ( 𝚫 H) is... Negative Positive - Entropy (S) - Enthalpy is not the only factor governing whether a reaction is spontaneous or nonspontaneous - Entropy (S): measure of disorder - ↑ disorder = ↑ S - ↓ disorder = ↓ S - Entropy increases when: - Solid reactant → liquid/gas product - Liquid reactant → gas product - Moles of reactant < moles of product - Complex molecules → simple molecules - Diffusion - Enthalpy/Entropy Interaction - - Free Energy (G) - Interaction between enthalpy, entropy, and temperature determine whether a reaction will be spontaneous - 𝚫 G = 𝚫 H - T 𝚫 S - Or simply, - 𝚫 G = G final - G initial - If G final < G initial - 𝚫 G is positive - Reaction is spontaneous - Endergonic reaction - If G final > G initial - 𝚫 G is negative
- Reaction is nonspontaneous - Exergonic reaction - 2nd Law of Thermodynamics - The entropy of the universe increases with any change that occurs - Adenosine Triphosphate (ATP) - Adenine + ribose + 3 phosphate groups = ATP - - Hydrolysis of ATP - Exergonic - Produces ADP and P i - Releases ~54 kJ/mol - Coupled to an endergonic reaction - Phosphate activates other molecules (phosphorylation) - - Redox Reactions - Recall: most chemical reactions just a transfer of electrons - Redox: reduction and oxygen - LEO GOES GER ! - L ose E lectrons is O xidation goes G ain E lectrons is R eduction - (reducing agent) (oxidizing agent) - OIL RIG - O xidation i s the L oss of Electrons R eduction i s the G ain of Electrons - A + e - → A - (reduction reaction) - A - e - → A + (oxidation reaction)
- Coupled Redox Reactions - -

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture