Understanding Cell Types and Structures
You'll encounter two main types of cells in biology: eukaryotic and prokaryotic cells, and the differences between them are massive. Eukaryotic cells are the complex ones that make up plants and animals, whilst prokaryotic cells are much simpler and include bacteria.
Animal cells contain several key organelles you need to know. The nucleus acts like the cell's control centre, containing all the genetic material that directs cell activities. The cytoplasm is a gel-like substance where most chemical reactions occur, packed with enzymes that speed up these processes.
Don't forget about mitochondria - these are the powerhouses where respiration happens to provide energy. Ribosomes handle protein synthesis by translating genetic information, whilst the cell membrane acts as a selective barrier controlling what enters and leaves the cell.
Plant cells share many features with animal cells but have some unique additions. The cell wall made of cellulose provides rigid support and protection. Chloroplasts are where photosynthesis occurs, allowing plants to make their own food from sunlight.
Quick Tip: Remember that plant cells have everything animal cells have, PLUS cell walls, chloroplasts, and large vacuoles!
Bacterial cells are completely different - they're prokaryotic, meaning they lack a proper nucleus. Instead, their chromosomal DNA floats freely in the cytoplasm. Many bacteria have a flagellum for movement and plasmid DNA that often carries genes for antibiotic resistance.