This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 1 April 1, 2008 April 1, 2008 Biology 113, Lecture 3 Biology 113, Lecture 3 Concepts: 6.1, 6.2, 6.3, 6.4, 6.5 and 6.6 Part 1 Part 1 - Overview Overview Tour of the cell Functions of individual organelles and macromolecular assemblies Organelles- Specialized cell compartments Most are bounded by membranes Membrane-bound organelles are found only in eukaryotes (cells with nuclei) Eukaryotic cells have internal Eukaryotic cells have internal membranes that compartmentalize their functions membranes that compartmentalize their functions Eukaryotic cell Overview of the animal cell Overview of the animal cell Figure 6.9 (free and membrane-bound) Figure 6.9 Overview of the plant cell Overview of the plant cell ? (storage) 1. Nucleus (genome, chromosomes) 2. Nucleolus (rRNA genes, ribosome synthesis) 3. Endoplasmic reticulum (smooth and rough) 4. Golgi apparatus (transport, modifications) 5. Mitochondria (energy production) 6. Lysosomes (digestion) and vacuoles (storage) 7. Chloroplasts (photosynthesis) 8. Cytoskeleton (structure and internal transport) Major organelles you should learn about. Major organelles you should learn about. Nucleus and the nuclear envelope Nucleus and the nuclear envelope Figure 6.10 DNA is organized into chromosomes which comprises chromatin Condensed during mitosis (transcriptionally inactive ) Dispersed at other time (transcriptionally active ) NUCLEUS Largest organelle Stores genetic information Site of RNA synthesis (transcription) Bounded by double membrane Pores permit molecular transport 2 Nucleolus Nucleolus Substructure within the nucleus Not membrane bound or enclosed Contains genes for ribosomal RNA Site of ribosome biosynthesis Performs protein synthesis Large and small subunits, both made up of RNA and proteins Ribosomes Ribosomes Small subunit Large subunit Ribosomes Ribosomes (contd.) (contd.) Ribosomes Cytosol Free ribosomes Bound ribosomes Large subunit Small subunit TEM showing ER and ribosomes Diagram of a ribosome 0.5 m Free ribosomes synthesize soluble cytoplasmic cellular proteins Endoplasmic reticulum (ER) Membrane-bound ribosomes synthesize exported or membrane-bound proteins Endoplasmic Reticulum (ER) Figure 6.12 Network of cyotplasmic tubes forms a pipeline Continuous with outer nuclear membrane Accounts for half the...
View Full Document