Principles of Cells
Human Anatomy Cells are the basic living structural, Eleventh Edition functional unit of the body
Gerard J. Tortora Cytology is the branch of science that & studies cells Mark T. Nielsen The human body has 100 trillion cells 200 CHAPTER 2 different cell types with a variety of Cells shapes, sizes and functions.
Copyright © 2007 by John Wiley & Sons, Inc.
Cell Diversity Generalized Cell
Sizes (diameter) Ovum – 140 µm RBC – 8 µm Major parts of a cell µm = 1/10,000 of a cm Shapes Plasma membrane Flat Cytoplasm Oval Cubed Organelles Star shaped Elongated Inclusions Concave Structures Flagella Cilia Microvilli
Fluid mosaic model of the plasma membrane Membrane Lipids
Phospholipids – 75% Lipid bilayer Glycolipids – 5% Self recognition Cholesterol – 20% Maintains integrity Maintains fluidity Membrane Proteins Functions of the Cell Membrane
Integral proteins Extend across the Communication phospholipid bilayer Shape & protection Channels Pores Maintains the electrochemical gradient Receptors Electrical separation of charge Transporters Enzymes Chemical (concentration gradient) Peripheral proteins Selective permeability Loosely attached to inner or outer surface Some substances easily travel across the Enzymes membrane and others do not Cytoskeletal anchors
Membrane Transport Membrane Transport
Active transport (uses ATP) Passive transport (kinetic energy not ATP) Primary active transport Net diffusion Molecule mover hydrolyzes ATP Movement of molecules from [high] to [low] Secondary active transport Facilitated diffusion Molecule mover does not hydrolyze ATP Movement of molecules from [high] to [low] Uses [gradient] created by primary active transport Transport molecule involved Vesicular transport Osmosis Endocytosis Movement of solvent from [high] to [low] Phagocytosis Filtration Pinocytosis Mechanical/hydrostatic pressure Receptor-mediated endocytosis Exocytosis
02_05 02_04 02_table_02 Cytoplasm
Made up of: Cytosol – aqueous part Organelles (except the nucleus) Inclusions
02_01 02_table_02
Nucleus Ribosomes
Largest organelle Synthesized in the Contains DNA nucleolus Ribosomal RNA Nuclear envelope Proteins Double membrane Protein synthesis Nuclear pores Free ribosomes Nucleolus Cellular proteins ER bound ribosomes Membrane or secreted proteins Endoplasmic Reticulum Golgi complex
Network of membranes Extends from nuclear envelope Provides a surface for chemical reactions Smooth ER Synthesis of lipids Rough ER Synthesis of membrane or secreted proteins
Golgi Complex Lysosomes
First described by Created by golgi Camillo Golgi Contain digestive Packaging and (hydrolytic enzymes) transport of protein & High acid (low pH lipids from the ER inside) Creates secretory H+ pumps in the vessicles membrane Creates lysosomes
Mitochondria Cytoskeleton
Powerhouse of the cell Microfilaments Actin Double membrane with enzymes on the inner Movement eg. muscles Mechanical support eg. membrane microvilli Cellular respiration Intermediate filaments Self-replicating Anchor organelles Have their own DNA Anchor cells to each other Microtubules Similar to prokaryotic cells Tubulin Get them from your Cell division mother Movement of cilia and flagella Microtubule arrangements in Centrosome w/ Centrioles cilia and flagella Organizing center for the growth of mitotic spindles in dividing cells & microtubules in non-dividing cells
Cell Division Somatic Cell Cycle
2 types of nuclear division Mitosis (somatic cell division) 2 identical daughter cells Diploid (2N) 23 pairs of homologous chromosomes Meiosis (reproductive cell division) 4 genetically different cells Haploid (1N) Sperm & Egg Cytokinesis Division of the cytoplasm
Mitosis For the next lecture period:
Visit my webpage and download the powerpoint handout for chapter 3 and bring it to class. http://napavalley.edu/apps/comm.asp?Q=P134
Read the sections in the text which discuss the topics on the outline for chapter 3 (tissues).