3/10 exercise phy

Overview of Exam and Testing Procedures

• First lecture worth 50 points out of 385 total.

• Instructor emphasizes importance of test material and expects students to be familiar with key concepts discussed in lectures.

• No exams are returned for review; students are encouraged to meet the instructor in office to discuss their performance.

• Grades posted in the lab below the door on the left side after entering.

• Instructor does not use Canvas for grading; recommends students track their own points.

Upcoming Lab Exam Details

• First Lab Exam: Scheduled for March 26, two weeks after spring break.

• Exam format includes:

  • Questions with multiple choice answers (true or false).

  • Graphing exercises (labeling x and y coordinates).

  • Calculations relevant to lab homework.

• Students must show their work and both the answer and work must be correct for calculations.

Enzymes and Their Role in Reactions

• All enzymes are proteins and have a three-dimensional structure.

• Function of Enzymes:

  • Catalyze reactions to convert reactants into products quickly.

  • Can be reused without changing their nature or the reaction outcome.

• Activation Energy:

  • Enzymes lower the activation energy required for reactions.

  • Without enzymes, reactions would occur too slowly for biological processes.

Factors Affecting Enzyme Turnover Rate

1. Temperature and pH:

   • Enzyme activity operates efficiently within a narrow temperature range.

   • Optimal temperatures and pH lead to maximum enzyme activity (inverted U relationship).

   • Importance of warming up before exercise to optimize enzyme function.

2. Law of Mass Action:

   • The concentration of reactants and enzyme activity directly impacts the conversion of reactants to products.

   • More reactants or enzyme concentration enhances reaction rates.

3. Allosteric Inhibition:

   • Allosteric sites on enzymes allow for regulation of activity, including inhibition by ATP when energy demands decrease.

   • PFK is an example of a rate-limiting enzyme that can be inhibited.

4. Cofactors and Coenzymes:

   • Cofactors:

     • Metal ions like calcium, magnesium, etc., required for enzyme activity.

   • Coenzymes:

     • Derived from vitamins. They assist in various enzymatic reactions.

     • Example coenzymes include:

       • NAD (Nicotinamide adenine dinucleotide): Derived from vitamin B3 (niacin).

       • FAD (Flavin adenine dinucleotide): Derived from vitamin B2 (riboflavin).

       • Coenzyme Q (ubiquinone): Functions primarily as an antioxidant.

       • Coenzyme A: Derived from vitamin B5 (pantothenic acid).

Importance of Understanding Metabolic Cycles

• Knowledge of reactants, enzymes, and products in metabolic cycles is critical for success in exams.

• Students must be proficient in each metabolic cycle to pass the second lecture exam, and memorization is important for learning content effectively.