Cell Membrane Notes

2. Functions of Cell Structures

Functions of Cell Structures

Chapter 3: Cell Biology - Part B

Understanding the specific functions of cellular structures helps us appreciate how cells maintain life processes. Each organelle and structure has evolved to perform specialized tasks essential for cell survival and function.

Plant Cell - Functional Overview

Protection & Shape

Controls Entry/Exit

Control Center

Photosynthesis

Storage & Support

Animal Cell - Functional Overview

Controls Entry/Exit

Control Center

Energy Production

Temporary Storage

Detailed Functions of Cell Structures

Part/Structure	Function	Found in
Vacuole	It is the space that has a watery fluid (cell sap) that contains dissolved water, mineral salts and waste products. In plants: Large permanent vacuole maintains cell pressure and provides structural support. In animals: Small temporary vacuoles assist in storage and transport of materials.	Both plant and animal cells
Cell Membrane	Cell membrane is a thin layer around the cell that holds the cell together. It acts like a fence and controls what goes in and out of the cell. Therefore, the cell can take in substances it needs and get rid of waste products. This selective permeability is essential for maintaining cell homeostasis.	Both plant and animal cells
Cytoplasm	It is a jelly-like liquid that fills inside the cell. The cytoplasm is where chemical reactions of the cell take place. It also contains small structures called organelles which have special functions. The cytoplasm provides a medium for organelle movement and nutrient transport.	Both plant and animal cells
Nucleus	The nucleus carries genetic information and controls what happens or all the activities of the cell. It contains DNA which provides instructions for protein synthesis, cell division, and inheritance. Often called the "brain" or "control center" of the cell.	Both plant and animal cells
Cell Wall	It is a thick, tough layer made from cellulose found on the outside of the cell. It covers the cell membrane in plant cells. Cell wall helps the cell to keep its shape. It protects the cell from mechanical damages and provides structural support to the entire plant.	Plant cells only
Chloroplast	It is an organelle in the cytoplasm of plant cells. Chloroplast contain green pigment called chlorophyll. Chlorophyll absorbs light that is used by plants to make their own food through photosynthesis. This process converts light energy, carbon dioxide, and water into glucose and oxygen.	Plant cells only

🔬 Key Takeaways

Universal Structures

Cell membrane, cytoplasm, nucleus, and vacuoles are found in both plant and animal cells, each performing essential life functions.

Plant Specializations

Cell walls provide structure and protection, while chloroplasts enable photosynthesis - making plants autotrophic organisms.

Functional Integration

All cell structures work together as an integrated system to maintain life, with each organelle contributing to overall cell function.

Page 46 | Cell Biology Textbook