Presentation on theme: "Eat like a bird You hear it about people who don’t eat much. People say they “eat like a bird.” Yet birds eat a larger proportion of their weight every."— Presentation transcript:
Eat like a bird You hear it about people who don’t eat much. People say they “eat like a bird.” Yet birds eat a larger proportion of their weight every day than even the heartiest human eaters. Birds eat a high-energy diet of seeds, fruit, worms, insects, fish or meat---maximum energy, minimum bulk. Digestion is fast and thorough. Food energy is spent in flight, in keeping warm-----in simply being a bird. What is the relationship between an animal’s metabolism and the amount of food it eats? Use a comparison between birds and humans in your answer. (look in your glossary for the word metabolism)
Macromolecule Review 4 major groups Monomers & Polymers Functions
Concept: Enzymes Lesson Essential Question: How would a change in enzyme activity affect a living system? To understand enzymes, we have to understand basic chemistry including chemical reactions and how living things use macromolecules to chemically obtain energy for life’s functions.
Chemical Reactions & Energy Energy is stored or released by chemical reactions Bonds are broken and new bonds formed between atoms Different substances can be produced Reactants are the starting materials for chemical reactions The newly formed substances are called products.
Chemical Reactions Chemical reactions are summarized by chemical equations Example: 6CO 2 +6H 2 O+sunlight energy C 6 H 12 O 6 + 6O 2 Reactants Products Arrow is read as “yields” or “forms”
Chemical Reactions Chemical reactions can release energy or absorb energy (also see fig. 6-15 & 6-16 in text) Example: fossil fuel burning, respiration Example: photosynthesis
Chemical Reactions & Life Metabolism is all of the chemical reactions that occur within an organism. Your cells get energy needed for metabolism from the food you eat. Chemical energy is converted into a useable form.
Chemical Reactions Energy is needed to start chemical reactions; we call this activation energy STOP: SUMMARIZE CHEMICAL REACTIONS in “Note Making” by yourself, then SHARE WITH LAB PARTNER
Enzymes All reactions need energy to start…called activation energy Catalysts are substances that speed up the rate of chemical reactions Enzymes are proteins that act as biological catalysts, greatly speeding up reactions in cells. Allows reactions to occur at much lower temperatures than normal…important for living things!
Enzymes, cont. Enzymes work because they provide a site where reactants can interact. The reactants in this case are called substrates Figure 6.18 in text show how substrates bind to the active site on the enzyme, react and then the products are released. Released products are things cells need to function… molecules big and small, regulating metabolism, releasing energy, etc.
Enzyme Reactions STOP: SUMMARIZE Enzymes in “Note Making” by yourself, then SHARE WITH LAB PARTNER On the BACK of your index card, write your answer to the lesson essential question … make an inference!