Enzymes, Cellular Respiration, and Genetics: Key Concepts

Key Concepts in Enzymes, Cellular Respiration, and Genetics

1. Free Energy Curve

In a catalyzed reaction, the enzyme lowers the activation energy required for the reaction, making it proceed more quickly. The free energy curve for the catalyzed reaction is shifted to the left compared to the uncatalyzed reaction.

2. Components in a Chemical Reaction

• Reactants: A and B
• Products: C and D (catalyzed)

3. Factors Affecting Enzyme Function

• Temperature: Enzymes have an optimal temperature; deviation can denature them.
• pH: Enzymes function best within a specific pH range.
• Substrate Concentration: Up to a point, increasing substrate concentration increases enzyme activity.

4. Definition of an Enzyme

Enzymes are biological catalysts that accelerate chemical reactions by lowering the activation energy, without being consumed in the process.

5. Cellular Respiration Chemical Formula

C6H12O6 + 6O2 → 6CO2 + 6H2O

• Substrates: Glucose (C6H12O6) and Oxygen (O2)
• Products: Carbon Dioxide (CO2) and Water (H2O)

6. Cellular Respiration Experiments

Hypothetical Experiment: Investigating the effect of temperature on cellular respiration rate.

• Setup: Vary temperatures, measure CO2 production.
• Expected Outcomes: Increased temperature initially increases rate; beyond an optimal point, rate decreases due to enzyme denaturation.

7. Location of Cellular Respiration

Cellular respiration occurs in the mitochondria of eukaryotic cells.

8. Mitosis and Meiosis Results

• Mitosis: 2 daughter cells, diploid, genetically identical.
• Meiosis: 4 daughter cells, haploid, genetically diverse due to crossing over.

9. Calculating Diploid or Haploid Number

If diploid number = 16, haploid number = 8. Divide the diploid number by 2 to get the haploid number, and multiply the haploid number by 2 to get the diploid number.

10. Somatic vs. Gametes

• Somatic Cells: Body cells (e.g., skin cells).
• Gametes: Reproductive cells (e.g., sperm, egg).

11. Genetic Variation in Meiosis

Crossing over in Prophase I results in the exchange of genetic material between homologous chromosomes, creating genetic diversity.

12. Telophase/Cytokinesis in Plant and Animal Cells

• Plant Cells: Cell plate forms during cytokinesis.
• Animal Cells: Cleavage furrow forms during cytokinesis.

13. Genetic Problems

• Genotype and Phenotype:
• Possible gametes: B, b. Phenotypic ratio: 1:1 (dominant: recessive).

14. Punnett Square (Monohybrid and Dihybrid)

• Monohybrid: RR x rr → All Rr.
• Dihybrid (Seed color Yy, Seed shape Rr): 9:3:3:1.

15. F2 Ratios for Monohybrid and Dihybrid Crosses

• Monohybrid: 3:1.
• Dihybrid (YyRr x YyRr): 9:3:3:1.