Cellular Energetics

1. Cellular Energetics Energy is needed in ALL organisms in order to perform work. The source of this energy is ultimately the sun, but it is vital to regulate the rate of chemical reactions through the use of biological catalysts Organisms must store energy in a usable form so again control the rate of chemical reactions

2. Matter and Energy • Matter: Anything that takes up space and has mass • Energy: The ability to do work (no mass, does not take up space) • Energy is conserved but constantly transformed • Different forms: radiant, kinetic, potential, thermal • Heat vs. temperature

3. Station 4 explanation • If only 10% of energy is transferred when it moves up the trophic level, where does this energy go?

4. Station 3 explanation • H2O2 H20 + O2 • 2H2O2 2H20 + O2 • Energy always required to break bonds, some reactions release a net amount of energy, some absorb a net amount of energy • Exothermic reaction: NET release of energy • Endothermic reaction: NET absorption of energy products reactant Energy

5. Station 3 explanation

6. Station 3 explanation • Organisms live at the expense of free energy, the energy available in a system for work • It combines the energy in bonds with the natural disorder of systems • ДG: Difference of free energy between reactants and products

7. Scientific reasoning with station 3

8. How does the enzyme catalase work? Catalase is built from repeated amino acids, therefore what kind of macromolecule are enzymes? A catalyst is anything that speeds up a reaction. Enzymes are biological catalysts • 2H2O2 2H20 + O2 • This reaction, like many others will happen on its own, but V E R Y S L O W L Y • Adding the enzyme catalasespeeds up the reaction. How?

9. Enzymes – Activation energy • Enzymes lower the activation energy needed to drive reactants to products by… -Bringing the substrates together -Orientating the substrates correctly -Putting strain on the bonds -Providing favorable conditions

10. Part I Part II Part III Deduction Materials Procedure Analysis questions (on a third page) Set up your notebook as followed (draw it while you work on the lab). Turn in cell booklet pages and keep ONLY catalase lab, notebook, pencil, and calculator on your desk.

11. Enzyme regulation (add on to notes from last class) • Substrate concentration: What happens when every active site is occupied by a substrate? How can the reaction rate be increased? • Temperature, pH, salinity can all alter an enzymes shaped, even denature it

12. Reading quiz • 1. List an example of an autotroph and an example of a heterotroph • 2. Autotrophs get energy from ____ or ___ to make organic compounds • 3. Heterotrophs use energy form ____ to make organic compounds • 4. Which molecule is the main source of energy “currency” • 5. How many phosphate groups does the molecule from question 4 have?

13. Sources of energy Photosynthesis (photoautotroph) Autotrophs (self-feed from CO2 and inorganic materials): plants, some algae, some bacteria Synonym: Producers Chemosynthesis (chemoautotroph)

14. Sources of energy Carnivores Omnivores Heterotrophs Synonym: Consumers Herbivores Detritivores

15. ATP • Energy in glucose is TOO great, so energy released from ATP is used instead P

16. Biology of Fireflies • Light produced via a chemical reaction in a photic organ • Luciferase is the enzyme that converts luciferin • Control of their bioluminescence still has several hypothesize as does the use of it