Cell Biology Fundamentals

Study Notes

Plasma Membrane: Semi-permeable membrane that surrounds the cell, regulating what enters and leaves
Cytoplasm: Jelly-like substance inside the cell where metabolic processes take place
Nucleus: Control center of the cell, containing most of the cell's genetic material (DNA)
Mitochondria: Organelles responsible for generating energy for the cell through cellular respiration
Endoplasmic Reticulum (ER): Network of membranous tubules and cisternae involved in protein synthesis and transport
Ribosomes: Small organelles found throughout the cytoplasm, responsible for protein synthesis
Lysosomes: Membrane-bound sacs containing digestive enzymes, responsible for cellular digestion and recycling
Golgi Apparatus: Complex of flattened sacs and tubules involved in protein modification, sorting, and secretion

Passive Transport: Movement of molecules from high to low concentration without energy input
- Diffusion: Random movement of molecules from high to low concentration
- Osmosis: Movement of water molecules through a selectively permeable membrane
Active Transport: Movement of molecules against their concentration gradient, requiring energy input
- Carrier proteins: Transport molecules across the membrane, using energy from ATP

Mitosis: Process of cell division resulting in two daughter cells with the same number of chromosomes as the parent cell
- Interphase: Cell grows, replicates DNA, and prepares for cell division
- Prophase: Chromatin condenses, nuclear envelope breaks down, and microtubules form
- Metaphase: Chromosomes align at the center of the cell
- Anaphase: Sister chromatids separate and move to opposite poles
- Telophase: Nuclear envelope reforms, and chromatin uncoils
- Cytokinesis: Cytoplasm divides, and the cell splits into two daughter cells
Meiosis: Process of cell division resulting in four non-identical daughter cells with half the number of chromosomes as the parent cell
- Meiosis I: Homologous chromosomes pair, exchange genetic material, and separate
- Meiosis II: Sister chromatids separate and move to opposite poles