Potential Quiz Questions

• Organelle responsible for Protein Synthesis:

  • Ribosomes are the organelles that synthesize proteins.

• Primary Function of the Cell Membrane:

  • The cell membrane serves as a barrier that regulates the movement of substances in and out of the cell, maintaining homeostasis.

• Movement of Large Molecules Across Membrane:

  • Large molecules are moved across the membrane via processes like endocytosis (intake) and exocytosis (export).

• Main Product of Glycolysis:

  • The main products of glycolysis are two molecules of pyruvate, with a net gain of 2 ATP and 2 NADH.

• Where the Calvin Cycle Occurs:

  • The Calvin cycle occurs in the stroma of chloroplasts in plant cells.

Transport in Cells

• Water Regulation Importance:

  • Water accounts for over 70% of the human body; improper regulation can lead to cell swelling or bursting, and brain damage due to swelling.

• Processes for Water Regulation:

  • Movement of water is regulated through osmosis.

Model 1 - Water Movement

1. Identifying Solute and Solvent:

   • Solute: Sugar molecules

   • Solvent: Water molecules

2. Molecule Movement:

   • Able to Move Through Membrane: Water molecules can pass through the selectively permeable membrane.

3. Molecule Count (In/Out):

   • Inside the Cell: 6 sugar molecules, 24 water molecules

   • Outside the Cell: 15 sugar molecules, 15 water molecules

4. Concentration Explanation:

   • More Concentrated Solution: Outside the cell (higher ratio of solute to solvent).

   • Change in Concentration:

     • The solution inside the cell will become less concentrated.

     • The solution outside will become more concentrated.

5. Dynamic Equilibrium Prediction:

   • Eventually, concentrations will reach equilibrium, with molecules entering and leaving at equal rates.

6. Definition of Diffusion:

   • Movement of molecules from high to low concentration; Model 1 demonstrates diffusion.

   • Water Concentration: Higher concentration of water is inside the cell, indicating diffusion is occurring as water moves to lower concentration.

Osmosis

• Definition of Osmosis:

  • Movement of water from high to low concentration across a semi-permeable membrane.

Concentration Comparisons and Definitions

• Hypertonic Solution Definition:

  • More water inside the cell.

• Hypotonic Solution Definition:

  • More water outside of the cell.

• Isotonic Solution Definition:

  • Equal concentrations inside and outside.

• Impact on Plant Cells:

1. Hypotonic - Cells grow/burst (Turgid).

2. Hypertonic - Cells shrunk (Plasmolysed).

3. Lysis in Animal Cells: The cell bursts; plant cells prevent this due to the cell wall.

Extension Questions on Osmosis and Water

• Spraying Produce: It maintains turgidity, making produce look fresh by replenishing lost water.

• Lettuce Salad with Salt: Salt causes water to move out of the lettuce, resulting in wilting due to osmosis.

• Overconsumption of Water: Can cause brain edema due to osmotic imbalance.

• Contractile Vacuole Function in Paramecium: It can help regulate osmotic pressure in freshwater environments.

Experimental Variables

1. Controlled Experiment Definition: Only one variable should be changed in a controlled experiment.

   • Independent Variable: Changed by the experimenter.

   • Dependent Variable: Changes as a result of the independent variable.

   • Controlled Variables: Kept Constant.

• Photosynthesis Model in Aquatic Plants:

• Variables Affecting Gas Production: Light exposure, water content, temperature.

Summarizing Cell Structure and Function

• Basic Unit of Life: The cell; functions include DNA containment in the nucleus, protein assembly in ribosomes, and energy conversion in organelles like mitochondria.

• Cell Structure Summary:

  • Organelles carry out specific functions, with membrane-regulated processes allowing for homeostasis.

  • Transport Types: Active transport requires energy, while passive transport includes diffusion and osmosis.