Cell Response to Osmosis and Transpiration

This page covers how animal cells respond to osmosis differently from plant cells and introduces the concept of transpiration in plants.

Definition: Transpiration is the evaporation of water from mesophyll cells, followed by diffusion through leaf air spaces and stomata.

Highlight: Animal cells can burst through cell lysis when too much water enters, as they lack a cell wall to provide structural support.

Example: Environmental factors affecting transpiration include:

• Higher temperatures increase evaporation and transpiration
• Stronger winds accelerate water vapor removal from stomata
• Higher humidity reduces evaporation and transpiration rates

Environmental Factors and Water Usage

This page delves deeper into how environmental conditions affect plant water movement and usage.

Highlight: Light intensity significantly impacts transpiration as many plants close their stomata in darkness to conserve water.

Example: The main environmental factors affecting transpiration can be demonstrated using:

• Temperature controls
• Humidity measurements
• Wind speed variations
• Light intensity adjustments

Vocabulary:

• Stomata: Pores in leaves that control gas exchange and water vapor release
• Mesophyll: The internal leaf tissue where photosynthesis occurs

Understanding Osmosis and Cell Transport

This page introduces fundamental concepts of osmosis and its effects on cells. The content explains how water moves between solutions of different concentrations through selectively permeable membranes.

Definition: Osmosis is the movement of water from a dilute solution to a more concentrated solution through a selectively permeable membrane.

Vocabulary:

• Concentrated solution: Contains a low concentration of water
• Dilute solution: Contains a high concentration of water
• Turgid: Firm and swollen due to water pressure

Example: In plant cells, when water enters through osmosis, the vacuole expands and pushes against the cell wall, creating turgor pressure.

Highlight: The cell wall in plant cells prevents excessive water intake and cell bursting through turgor pressure. When a plant cell loses too much water, it becomes plasmolysed, with the cell membrane pulling away from the cell wall.