Enzyme Functions and ATP

Enzyme Functions and ATP To complete this worksheet, select: Module: Foundations Activity: Animations Title: Enzyme Functions and ATP Introduction 1. Define and describe apoenzyme and coenzyme parts of an enzyme. The protein component of an enzyme is called the apoenzyme. The coenzyme is an organic molecule that may be attached to the enzyme. Properties of Enzymes 2. Describe three enzyme characteristics. specificity – enzymes binds only to specific substrates and exhibit absolute specificity. efficiency - Under the best of conditions enzymes can catalyze reactions at rates from 100 million to 10 billion times faster than similar reactions without enzymes. regulation –Regulation is based on available substrate, temperature, pH and salinity. gene control - The regulation of the synthesis and action of enzymes is under individual genetic control. inhibition – substances within the cell can act to inhibit the action enzymes. Most enzymes have both active and inactive forms. activation – Enzymes function to lower the activation energy of a reaction by decreasing the randomness of collisions that occur between molecules. Mechanism of Enzyme Action 3. Describe the enzyme mechanism. Role of enzyme shape - The shape of the enzyme molecule dictates the complementary shape of the substrate molecule. Enzymes exhibit absolute specific or ‘lock and key’ where their shape will dictate their function. Reuse of enzyme molecules – Enzymes are not degraded but reused and recycled after they have affected hydrolysis in organic molecules. Enzymatic Breakdown of ATP 4. Explain the importance of ATP as an energy molecule. ATP derived from the oxidation of glucose, and other organic molecules, provides on hydrolysis, available free energy for cellular chemical reactions. 5. What is the function of ATPase? Is used to hydrolyze ATP into ADP + phosphate group + energy. 6. a. How is energy needed to transport materials across the cell membrane? Energy is used to transport molecules by providing the necessary means to pump ions across a membrane against a concentration gradient b. What is the role of the sodium-potassium pump or ATPase, in this process? The Na+-K+ pump utilizes ATPase to hydrolyze ATP to provide available energy to pump Na+ ions out of the cell against a concentration gradient. 7. a. How is energy needed to contract muscle? In order to slide the myosin and actin myofilaments together there needs to be an interaction between actin and myosin. ATPase hydrolyses ATP that allows for actin and myosin myofilaments interaction: energy is required to allow actin and myosin myofilaments to interact. b. What is the role of the myosin ATPase? The myosin ATPase located in the cross bridge allows , when released, the hydrolysis of ATP t produce energy for muscle contraction To hydrolyze the ATP located on the actin molecule. 8. Describe the role of ATP for glycogen synthesis. Glycogen is made by polymerizing individual glucose molecules together with the aid of ATP for the dehydration synthesis process. Summary 9. In summary, can you identify three examples of requiring energy and ATPase? active transport – sodium potassium pump. movement – the flagellum on the spermatozoa. synthesis – the formation of glycogen from the successive binding of glucose molecules.