Overview
This lab covers the structure and function of human cells, key organelles, disorders related to organelle malfunction, and the stages and significance of mitosis.
Human Cell Types and Functions
- Bone cells regulate bone formation and resorption for skeletal integrity.
- Muscle cells are responsible for movement and contractions.
- Red blood cells transport oxygen throughout the body.
- Sex cells fuse with opposite gametes to create new organisms.
- Skin cells protect against injury and hazardous substances.
- Stem cells replace damaged or lost cells.
Somatic vs. Sex Cells
- Somatic cells have a diploid number of 46 chromosomes.
- Sex cells (gametes) have a haploid number of 23 chromosomes.
Major Cell Structures and Organelles
- The nucleus stores genetic material (DNA).
- The nucleolus houses DNA, RNA, and proteins within the nucleus.
- Ribosomes synthesize proteins.
- Mitochondria produce cellular ATP using oxygen.
- Lysosomes contain hydrolases to digest worn-out cell parts.
- Peroxisomes oxidize organic substances.
- Smooth ER synthesizes and transports materials for cell growth.
- Rough ER, covered in ribosomes, is key in protein synthesis.
- Golgi apparatus modifies proteins and packages them for transport.
- Centrosomes organize microtubules during cell division.
- The cytoskeleton provides structural support for the cell.
Cell Disorders and Organelle Dysfunction
- Kearns-Sayre syndrome (mitochondria): causes energy deficiency and muscle weakness.
- X-linked adrenoleukodystrophy (peroxisomes): impairs fatty acid breakdown in neurons.
- Treacher Collins syndrome (ribosomes): disrupts protein synthesis, affecting facial development.
- Cystic fibrosis (rough ER): results from defective protein synthesis affecting mucus production.
- Tay-Sachs disease (lysosome): lipid buildup destroys nerve cells.
- Hutchinson-Gilford progeria (nucleus): mutation causes accelerated aging.
Mitosis and Cell Cycle
- Mitosis is cell division yielding two identical daughter cells.
- Occurs in somatic cells for growth and repair.
- Stages of mitosis: prophase, metaphase, anaphase, telophase, cytokinesis.
- Interphase (G1, S, G2) is the cell's non-dividing preparation phase.
- G0 is the resting phase; S phase involves DNA replication.
- Human somatic cells have 46 chromosomes after mitosis.
Stages of Mitosis (Key Features)
- Interphase: cell grows, replicates DNA, no visible chromosomal changes.
- Prophase: chromatin condenses, spindle forms, nucleolus disappears.
- Metaphase: chromosomes align at cell center, nucleus dissolves.
- Anaphase: sister chromatids separate to opposite poles.
- Telophase: nuclear envelope re-forms, chromosomes decondense, nucleoli reappear.
Key Terms & Definitions
- Mitosis — process of cell division producing two identical daughter cells.
- Somatic cell — any body cell except gametes, diploid chromosomes.
- Sex cell (Gamete) — sperm or egg cell, haploid chromosomes.
- Organelle — specialized cell structure with a specific function.
Action Items / Next Steps
- Review and label organelles on cell models in lab.
- Use slides and microscopes to identify mitosis stages.
- Study bold terms and be prepared to match organelles and their functions.