AP Bio: Tuesday, 9.27.11 Metabolic Reactions & Enzymes Homework: Pass PS 4 to the front to be collected PS 5 due a week from today Do Now: Today is a lecture/notes day… take out a notebook (title for today is at the top of the slide) The following terms can be divided into two logical categories. Split them as best you can into two lists. Endergonic Synthesis Condensation Exergonic Decomposition Hydrolysis Catabolism Cellular respiration Anabolism Photosynthesis

Today’s Agenda & Goals Agenda: Goals: Lecture on Metabolic Reactions & Enzymes Goals: Distinguish between endergonic and exergonic reactions Describe the role of ATP in metabolic reactions Explain the role of enzymes as biological catalysts

Video #1: Energy in Living Things 1st Law of Thermodynamics: Energy can’t be created or destroyed, it only changes forms. Forms of energy – Potential (stored) – includes chemical energy (energy held in chemical bonds) (ex: glucose, ATP, fatty acids) Kinetic (movement) – includes heat energy (the most random/disordered form) 2nd Law of Thermodynamics: Every energy transfer involves the “loss” of some energy as heat (so the total amount of “disordered” energy increases overall)

Two categories of metabolic reactions… Hydrolysis Decomposition Catabolism Cellular respiration Exergonic Condensation Synthesis Anabolism Photosynthesis Endergonic

How do cells power endergonic reactions? ATP

ATP – Your cells’ rechargeable battery

The ATP/ADP Cycle is coupled with other cellular reactions

AP Bio: Wednesday, 9.28.11 Metabolic Reactions & Enzymes (Day 2) Homework: Lab 2A Analysis Questions (page 3) Lab 2B and 2C Pre-Lab (page 4) Do Now: On the Lab 2 packet, read the Overview and answer the Pre-Lab Questions on pages 1-2. Today’s Agenda: Lab 2 Pre-Lab and Demonstration Lecture (continued) – Enzymes

Video #2: Controlling Cellular Metabolism

Even exergonic reactions require activation energy.

Catalysts lower the energy barrier.

How do enzymes work? Specificity – every enzyme’s shape matches its substrate Substrate binds to enzyme’s active site Induced fit – enzyme and substrate both change shape slightly Bond strain lowers the EA needed to break substrate bonds Substrate turns to product; enzyme remains unchanged

Enzyme shape is essential!

AP Bio: Thursday, 9.29.11 Lab 2: Enzyme Catalysis Homework: Lab 2 Graphs and Analysis Questions Do Now: Take out Lab 2 and turn to page 3. Today’s Goals: Quantitatively measure the rate of an enzyme-catalyzed reaction Experimentally determine how temperature, pH, and substrate concentration affect the rate of an enzyme-catalyze reaction

AP Bio: Thursday, 9.29.11 Lab 2: Enzyme Catalysis HW: Lab 2 (graphs and analysis questions) due Tuesday Prob Set 5 now due Wed. not Tuesday! Agenda: Discussion: Part A and Pre-Lab for Parts B and C (5 min) Demonstration of lab set-up (5 min) Lab! Part B, then Part C Today’s Goals: Quantitatively measure the rate of an enzyme-catalyzed reaction Experimentally determine how temperature, pH, and substrate concentration affect the rate of an enzyme-catalyze reaction

AP Bio: Tuesday, 10/4/11 Lab Debrief; Enzyme Regulation Homework: Problem Set 5 due Wednesday Unit Test on Ch. 1-5 and 8 on TUESDAY (see review sheet) Do Now: Take out Lab 2 and your graphs Today’s Goals: Analyze data from Lab 2 Explain how enzyme activity is regulated in cells

Video of Peroxidase in Action… See Starr cd ch. 5 catalase

Videos on Protein Shape…

Enzyme Regulation

Competitive Inhibition

Non-Competitive Inhibition

Allosteric Regulation

Allosteric Regulation A regulator must bind in order to activate the enzyme Similar to, but opposite from, non-competitive inhibition

FEEDBACK INHIBITION

AP Bio: Wednesday, 10.5.11 Unit 1 Test Review! Homework: Study for tomorrow’s test! Do Now: Take out PS 5 Take 15-20 minutes to answer the practice questions in the packet Objectives: Review the material on the Unit 1 Test Agenda: Practice questions / Hand back PS 4 Discuss practice questions & other review topics Hand in PS 5