Cell Theory and Organelles

Study Notes

Cell Theory

All living organisms are composed of cells.
Cells are the smallest units of life capable of carrying out all life functions.
All cells arise from pre-existing cells through cell division.

Cell Types

Prokaryotes lack membrane-bound organelles and have few internal structures.
- Bacteria are examples of prokaryotes.
Eukaryotes contain membrane-bound organelles.
- Most living organisms are eukaryotes.

Cell Parts - Organelles

Cell Membrane
- Outer membrane of the cell, regulating movement in and out of the cell.
- Composed of a double layer.
Cell Wall
- Commonly found in plant cells and bacteria.
- Provides structural support and protection to the cell.
Nucleus
- Directs the cell's activities.
- Separated from the cytoplasm by the nuclear membrane.
Nuclear Membrane
- Encloses the nucleus.
- Comprised of two layers with openings for material exchange.
Chromosomes
- Located within the nucleus.
- Composed of DNA and contain instructions for traits and characteristics.
Nucleolus
- Found within the nucleus.
- Contains RNA, essential for protein synthesis.
Cytoplasm
- Gel-like mixture surrounding the cell membrane.
- Contains hereditary material.

Organelles Involved in Cellular Processes:

Endoplasmic Reticulum (ER)
- Network of membranes involved in the transportation of materials within the cell.
- Smooth ER lacks ribosomes.
Ribosomes
- Present in thousands in each cell.
- Responsible for protein synthesis.
- Found attached to the ER or free-floating within the cytoplasm.
Mitochondria
- Generate energy through chemical reactions, breaking down fats and carbohydrates.
- Regulate water and other material levels within the cell.
- Recycle and decompose proteins, fats, and carbohydrates.
Golgi Apparatus
- Acts as the cell's protein "packaging plant".
- Moves materials within the cell and transports them out of the cell.
Lysosomes
- Act as the cell's digestive system for proteins, fats, and carbohydrates.
- Transport undigested materials to the cell membrane for removal.
- If a lysosome explodes, the cell breaks down.
Vacuoles
- Membrane-bound sacs for storage, digestion, and waste removal.
- Contain a water solution.
- Help plants maintain their shape.
Chloroplasts
- Primarily found in plant cells.
- Contain chlorophyll, which gives plants their green color.
- The site of photosynthesis.

Description

Explore the fundamental concepts of cell theory and the types of cells. Learn about the differences between prokaryotes and eukaryotes, as well as the various organelles that comprise eukaryotic cells. This quiz will enhance your understanding of cellular structures and their functions.