CELLS AND MICROSCOPES

• Cells


  • Smallest unit that is capable of living
  • It makes all the tissues of an organisms
• Cell has THREE (3) main parts

  • DNA: Genetic material
  • Cytoplasm: Platform for organelles to function
  • Cell membrane: Separates the cell from the external environment

  
• Microscope


  Device used to view cells
• Types of microscopes


  • Light Microscope
  • Electron Microscope
  • Scanning Electron Microscope (SEM)
  • Transmission Electron Microscope (TEM)

  
• Prokaryotic cells


  • Cell membrane
  • Cell Wall
  • Cytoplasm
  • Nucleoid
  • Plasmids
  • Flagella
  • Pili
  • Fimbrae

  
• Animal cells (Nucleus)


  • Nucleus
  • Nucleolus
  • Chromatin
  • DNA
• Animal cells (Endomembrane System)

  • Mitochondria
  • Endoplasmic reticulum
  • Golgi Apparatus
  • Vesicles
  • Lysosomes
  • Peroxisomes
  • Plasma membrane

  
• Animal cells (Cytoskeleton)


  • Microtubules
  • Intermediate filaments
  • Microfilaments

  
• Plant cells


  • Chlorophyll
  • Cell Wall
  • Large Vacuoles

  
• Extracellular Matrix (ECM)


  • Complex network of macromolecules that surround and support cells in tissues
  • Components: Collagen, Glycoaminoglycans (GAG's), Proteoglycans
  • things outside of the cell

  
• Functions of ECM

  • Support and anchorage
  • Regulation of cell behavior
  • Signaling pathways
• Cell cycle


  Series of events that occur in a eukaryotic cell leading to its division and duplication
• Phases of the cell cycle

  • G1 phase
  • S phase
  • G2 phase
  • M phase
• G1 phase


  Cell growth and preparation for DNA synthesis
• S phase


  DNA replication
• G2 phase


  Protein and organelle synthesis, preparation for cell division
• M phase


  Cell division (Mitosis)
• Importance of the cell cycle

  • Growth and development
  • Tissue repair and regeneration
  • Maintenance of chromosome number
  • Reproduction
  • Evolution
• Mitosis


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase
• Cytokinesis


  Physical separation of the two daughter cells
• Meiosis


  Cell division that reduces the number of chromosomes in gametes
• Phases of Meiosis

  • Prophase I
  • Metaphase I
  • Anaphase I
  • Telophase I
  • Prophase II
  • Metaphase II
  • Anaphase II
  • Telophase II
• Specialized cells


  Cells that have developed unique structures and functions to carry out specific tasks in the human body
• Examples of specialized cells

  • Nerve cells
  • Muscle cells
  • Blood cells
  • Epithelial cells
  • Bone cells
  • Fat cells
  • Reproductive cells
• Number of daughter cells

  • Two
  • Four
• Chromosome number

  • Parents: 2n → Daughter: 2n
  • Parents: n → Daughter: n
• Stages


  • PMAT
  • PMAT I & PMAT II
• Meiosis (Summarize)
• Specialized cells

  Cells that have developed unique structures and functions that allow them to carry out specific tasks in the human body
• Specialized cells work together to form the tissues, organs, and systems that make up our bodies
• Specialized cells perform essential functions such as transmitting nerve impulses, contracting muscles, and transporting oxygen throughout the body
• Types of specialized cells

  • Nerve cells
  • Muscle cells
  • Blood cells
  • Epithelial cells
  • Bone cells
  • Fat cells
  • Reproductive cells
• Nerve cells


  Transmit electrical and chemical signals throughout the body
• Nerve cells

  • Cell body contains the nucleus and other organelles
  • Dendrites are short branching extensions that receive signals from other neurons
  • Axon is a long, thin extension that transmits signals away from the cell body
• Types of neurons

  • Sensory neurons
  • Motor neurons
  • Interneurons
• Synapse


  Junction between two neurons or between a neuron and a target cell
• Neurotransmitters

  Chemicals released at the synapse that transmit signals from one neuron to another
• Action potential


  Rapid change in the electrical charge of a neuron that occurs when it is stimulated, triggering the release of neurotransmitters and the transmission of signals to other neurons
• Myelin


  Fatty substance that surrounds and insulates the axons of some neurons, increasing the speed and efficiency of signal transmission
• Plasticity


  Neurons' ability to change and adapt in response to experience or injury, allowing the brain to reorganize itself and form new connections