Overview
This lecture covers the main structures and functions of the cell model, focusing on organelles, their roles, and how materials are moved in and out of the cell.
Endoplasmic Reticulum
- The smooth endoplasmic reticulum (ER) is involved in lipid and hormone production.
- The rough ER, which has ribosomes attached, is the site of protein synthesis.
Organelles and Their Functions
- Mitochondria (kidney bean-shaped, orange) are where ATP (energy) is produced.
- Peroxisomes (yellow) help break down fatty acids.
- Lysosomes (brown) contain enzymes to break down cellular substances (waste management).
- Free ribosomes also produce proteins, not attached to the ER.
Nucleus and Related Structures
- The nucleus (blue) houses DNA and controls cell activities.
- Nuclear pores (dark blue) allow RNA to move in and out of the nucleus.
- The nucleolus (white, inside nucleus) makes ribosomal subunits.
- Chromatin (brown) is the genetic material (DNA and proteins) within the nucleus.
- Centrioles (pink) are involved in cell division.
Golgi Apparatus and Vesicle Transport
- The Golgi apparatus modifies, packages, and ships proteins (mail system of the cell).
- Proteins are sent to the Golgi from the rough ER or free ribosomes.
- Secretory vesicles allow proteins to exit the cell via exocytosis.
- Endocytosis refers to the cell engulfing materials and bringing them inside.
Key Terms & Definitions
- Smooth Endoplasmic Reticulum (Smooth ER) — site of lipid and hormone synthesis.
- Rough Endoplasmic Reticulum (Rough ER) — site of protein synthesis, studded with ribosomes.
- Mitochondria — produce ATP (cellular energy).
- Peroxisomes — organelles that break down fatty acids.
- Lysosomes — organelles with enzymes for breaking down waste.
- Free Ribosomes — unattached structures that make proteins.
- Nucleus — cell control center containing DNA.
- Nuclear Pores — openings allowing RNA movement in/out of the nucleus.
- Nucleolus — produces ribosomal subunits.
- Chromatin — DNA and protein within the nucleus.
- Centrioles — assist in cell division.
- Golgi Apparatus — modifies, packages, and ships proteins.
- Exocytosis — process where substances are released from the cell.
- Endocytosis — process where substances are brought into the cell.
Action Items / Next Steps
- Review the structure and function of each organelle.
- Be able to identify organelles and explain their roles on a cell model.