Page 2: Active Transport and Cell Structure

This section delves into active transport against concentration gradient and cellular pressure mechanisms. It explains how cells maintain balance and transport substances against concentration gradients.

Definition: Active transport is the movement of substances from a dilute to a concentrated solution against a concentration gradient, requiring energy from respiration.

Highlight: The greater the rate of cellular respiration, the more energy is available for active transport.

Example: When sugar molecules hit the cell membrane, they bounce away, while water molecules can pass through, demonstrating selective permeability.

The page also introduces chromosomes and their role in cell division, explaining how DNA is organized within the nucleus and its importance in genetic information storage.

Page 1: Transport Mechanisms in Cells

The page explores fundamental cellular transport processes, focusing on diffusion and its role in living systems. The text details how substances move across cell membranes and the factors affecting transport rates.

Definition: Diffusion is the net movement of particles from an area of high concentration to low concentration until equilibrium is reached.

Example: During photosynthesis, CO₂ diffuses into leaves through stomata, where palisade cells utilize it. The lower CO₂ concentration inside the leaf creates a concentration gradient.

Highlight: The rate of diffusion can be enhanced by:

• Increasing surface area
• Decreasing particle travel distance
• Increasing concentration gradient

Vocabulary: Partially permeable membranes are cell structures that allow some particles to pass through while blocking others.

The text explains how osmosis process in plant cells works, defining it as water movement from dilute to concentrated solutions through a partially permeable membrane. It also introduces the concept of water potential and its importance in cellular processes.