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

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

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

Station 3 explanation H 2 O 2  H O 2 H 2 O 2  H O 2 2H 2 O 2  2H O 2 2H 2 O 2  2H O 2 Energy always required to break bonds, some reactions release a net amount of energy, some absorb a net amount of energy 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 Exothermic reaction: NET release of energy Endothermic reaction: NET absorption of energy Endothermic reaction: NET absorption of energy reactant products Energy

Station 3 explanation

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

Scientific reasoning with station 3 Macroscopicsketch Microscopicsketch Explanation Reaction graph

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

Enzymes – Activation energy Enzymes lower the activation energy needed to drive reactants to products by… 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

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. Part I Part I Part II Part II Part III Deduction Materials Procedure Analysis questions (on a third page)

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? 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 Temperature, pH, salinity can all alter an enzymes shaped, even denature it

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

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

Sources of energy Heterotrophs Synonym: Consumers Herbivores Carnivores Omnivores Detritivores

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

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