Cell Biology PDF

The Cell Grace M. Bardelosa, MD, FPDS, FPSAi Assistant Professor IV Department of Human Structural Biology FEU- Dr. Nicanor Reyes Medical Foundation  Intended Learning Outcomes Define cell and cellular differentiation. Explain the importance of the plasma membrane. Describe the parts and fu...

The Cell Grace M. Bardelosa, MD, FPDS, FPSAi Assistant Professor IV Department of Human Structural Biology FEU- Dr. Nicanor Reyes Medical Foundation  Intended Learning Outcomes Define cell and cellular differentiation. Explain the importance of the plasma membrane. Describe the parts and functions of cytoplasmic organelles. Distinguish between cytoskeletons as to their structural cell support and movements. Describe the parts and functions of the components of the nucleus. Illustrate the cell cycle and its phases. Differentiate between mitosis and meiosis Explain stem cells and their role in tissue renewal. Explain the concept of apoptosis and give its examples. Differentiate parenchyma and stroma as to their definition and examples. Categorize cells based on their morphological characteristics.  Cell Basic structural and functional unit Smallest living parts of the body Plasma membrane Nucleus Cytoplasm  Cell Differentiation A specialization process Expresses genes mediating cytoplasmic activities Organized as tissues Specialized functions Changes shape accordingly Cell Differentiation  Plasma Membrane Phospholipid bilayer Contains cholesterol, proteins, carbohydrates Boundary of the cell Functions: ○ Physical barrier ○ Selective permeable membrane ○ Electrochemical gradients ○ Communication Plasma Membrane Cytoplasm Cytosol Viscous fluid medium with dissolved solutes Provides support for organelles Medium through which diffusion occurs Organelles Carry out specific metabolic activities of the cell  Cytoplasmic Organelles Rough ER Smooth ER Golgi apparatus Modifies, transports, and stores Synthesizes, transports, and Modifies, packages, and sorts proteins produced by attached stores lipids; metabolizes materials that arrive from the ER ribosomes; carbohydrates; detoxifies in transport vesicles; forms these proteins are secreted, become drugs, alcohol, and poisons; secretory vesicles and lysosomes components of the plasma membrane, forms vesicles and or serve as enzymes of lysosomes peroxisomes  Cytoplasmic Organelles Vesicles Lysosomes Peroxisomes Transport cellular material Digest microbes or materials Detoxify specific harmful (ex: ingested by the cell, worn- substances either produced by EX: CHICKEN FOX out cellular components, or the the cell or taken into the cell; entire cell) engage in beta oxidation of fatty acids to acetyl CoA KILLER  Cytoplasmic Organelles Mitochondria Ribosomes Cytoskeleton Synthesize most ATP during Engage in protein synthesis: Maintains intracellular aerobic cellular respiration by Bound ribosomes produce structural support and digestion of fuel molecules proteins that are secreted, organization of cells; (ex: glucose) in the presence incorporated into plasma participates in cell division; of oxygen membrane, and within facilitates movement lysosomes; free ribosomes produce proteins used within the cell  Cytoskeletons Protein polymers that determine the shapes of cells Important role in the movements of organelles and cytoplasmic vesicles Allow the movement of entire cells Structure Important Function Microfilaments Actin protein monomers organized Maintain cell shape; support microvilli; separate into two thin, intertwined protein two cells during cytokinesis (a process of cell filaments (actin filaments) division); facilitate change in cell shape; participate in muscle contraction Intermediate Various protein components Provide structural support; stabilize junctions filaments between cells Microtubules Hollow cylinders composed of Maintain cell shape and rigidity; organize and tubulin protein move organelles; support cilia and flagella; participate in vesicular transport; separate chromosomes during the process of cell division  Nucleus The largest structure within a cell ○ Nuclear envelope ○ Chromatin ○ Nucleolus Houses genetic material ○ Directs all cellular activities and regulates cellular structure Produces ribosomal units in the nucleolus  Components of the Nucleus LIVER CELL Nuclear Envelope Chromatin Nucleolus Forms a selectively Chromatin is the A generally spherical, permeable barrier combination of DNA and highly basophilic sub- between the nuclear its associated proteins domain of nuclei in and cytoplasmic involved in the cells actively compartments organization and function engaged in protein of DNA synthesis The Cell  The Cell Cycle Regular sequence of events that produce new cells Four phases ○ Mitosis ○ G1: time gap between mitosis and beginning of DNA replication ○ S: period of DNA synthesis/ replication ○ G2: gap between DNA duplication & the next mitosis The Cell Cycle Phases of Mitosis  Mitosis phases Prophase Metaphase Nucleolus disappears Chromosomes dragged to Chromosome spindle or equatorial plate condensation Metaphase checkpoint Mitotic spindle Anaphase Telophase Splitting of the centromere Chromosomes uncoil Exact division of the Nuclear envelope duplicated genetic reassembles material Nucleolus reappears  Basic Differences Mitosis Meiosis Cell division of somatic Type of reproduction Division of germ cells cells EX: EGG AND SPERM Count of daughter cells 2 diploid cells 4 haploid cells Altered number of Same Halved chromosomes Number of Chromosomes 23 pairs 23 chromosomes Mitosis vs Meiosis  Stem Cells *EVERYTHING COMES FROM STEM CELL BUT NOT ALL WILL DIFFERENTIATE *VERY GOOD CELLS REPLACING CANCER CELLS Undifferentiated Renew the differentiated cells of tissues as needed Division is asymmetric One daughter cell remains as stem Progenitor cells or transit amplifying cells: committed to differentiation Stem Cells  Cell Population Rapidly Renewing Stable Static Rapidly dividing Cells that divide Cells no longer progeny of the cells episodically and slowly divide committed to Stimulated by injury Ex: CNS cells differentiation Skeletal muscles Ex: Blood cells Ex: Periosteal cells - BONE Cardiac muscles Skin cells Perichondrial cells - CARTILAGE Cells lining the Smooth muscle cells digestive tract and endothelial cells EX: NADAPA of blood vessels CAN BE FOUND IN Fibroblasts BLOOD CELLS OF THE SKIN, GI TRACT LINING  Apoptosis The process of cell suicide Rapid, highly regulated cellular activity Shrinks, eliminates defective & unneeded cells Do not rupture No release of contents EX: 1. Epithelial cells 2. destroying themselves T LYMPHOCYTES 3. cells that are programmed to die (ex: the webbed of the fingers Apoptosis  Examples of Apoptosis Preset limited lifetime (epithelial cells of skin or GIT lining) Triggered to destroy themselves (developing T lymphocytes in clonal deletion) During development, certain cells programmed to die (webs between fingers & toes) Certain cells grow & regress (ovarian follicles, corpus luteum to albicans) Cell death of abnormal cells (cells infected by viruses or with genetic mutations)  Cell Death Apoptosis Necrosis Programmed cell death Accidental cell death A physiologic process A pathologic process Activation of an internally encoded Cells are exposed to unfavorable suicide program physical or chemical environment Controlled autodigestion Rapid cell swelling and lysis  Classification of Cells Parenchyma Stroma Functionally specialized Less specialized cells supporting tissue Principal Other cells and fibers that Characteristic cells of the form the framework of organ tissues and organs EX: liver (hepatocyte), heart, collagen and fibroblasts Morphological Characteristics Parenchyma Shape of cell Arrangement of the cells Number of nucleus Location of the nucleus Thank you Do you have any questions? 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