Overview
This lecture introduces the main parts of an animal cell and explains their functions, focusing on structures visible under a microscope and their roles within the cell.
Animal Cell Structure
- Animal cells are eukaryotic, meaning their DNA is enclosed in a nucleus.
- Under a light microscope, you can see the nucleus, cytoplasm, and cell membrane of animal cells.
- The nucleus contains the cell’s genetic material (DNA) and controls cell activities.
- The cytoplasm is a watery solution where most chemical reactions, such as the first stage of respiration, take place.
- The cell membrane surrounds the cell and regulates the movement of molecules in and out.
Organelles and Their Functions
- Mitochondria are the sites of aerobic respiration and produce energy for the cell.
- Mitochondria are usually too small to be seen with a light microscope; special stains or electron microscopes are needed.
- Ribosomes are the sites where protein synthesis occurs.
- Ribosomes are extremely small and require an electron microscope to be seen.
- Proteins made by ribosomes serve many functions in the cell, including as enzymes.
Exam Preparation and Practice
- You may be asked to identify cell structures in diagrams, such as nucleus, cytoplasm, cell membrane, mitochondria, and ribosomes.
Key Terms & Definitions
- Eukaryotic — cells with DNA enclosed in a nucleus.
- Nucleus — organelle containing genetic material and controlling the cell.
- Cytoplasm — jelly-like fluid where chemical reactions occur.
- Cell membrane — controls what enters and exits the cell.
- Mitochondria — site of aerobic respiration, energy production.
- Ribosomes — organelles involved in protein synthesis.
- Protein synthesis — process of making proteins from amino acids.
Action Items / Next Steps
- Practice labeling animal cell diagrams and identifying structures.
- Review additional questions on animal cell structure in the vision workbook.