General Biology 1 & 2 🦠🧪🧫🧬

• Cells


  Smallest unit of living organisms
• Discovery of Cells

  • Robert Hooke (1665) - Observed silver of cork-Saw "row of empty boxes" - Coined the term cell
  • Theodor Schwann & Matthias Schleiden (1839) - "All living things are made of cells"
  • Rodolph Rudolf Virchow (50 years later) - "all cells come from cells"
• Principles of Cell Theory

  • All living things are made of cells
  • Cell- smallest unit of organism
  • All cells arise from pre-existing cells
• Characteristics of Cells


  • Surrounding membrane
  • Protoplasm-cell contents in thick fluid
  • Organelles-structures for cell function
  • Control center with DNA
• Prokaryotic Cells


  First cell type on earth, no membrane bound nucleus, organelles not bound by membranes
• Eukaryotic Cells


  Cell type of Fungi, Protists, Plants and Animals, nucleus bound by membrane, possess many organelles
• Animal Cell


  • 10-30 micrometers in length
  • Typically round or irregular in shape
  • Possess many organelles
• Plant Cell


  • 10-100 micrometers in length
  • Typically Rectangular or cubic in shape
  • Possess many organelles
• Plasma membrane


  Double layer of phospholipids & proteins, interacts with water
• Membrane Proteins


  • Channels or transporters
  • Receptors
  • Glycoproteins
  • Enzymes
• Cytoskeleton


  • Made of microfilaments, microtubules, intermediate filaments
  • Provides mechanical support
  • Anchors organelles
  • Helps move substances
• Cell Walls


  Found in plants, fungi, and many protists, surrounds plasma membrane
• Cytoplasm


  Viscous fluid containing organelles, filaments, fibers, cytosol, storage substances
• Cilia and Flagella


  Provide motility, cilia are short and move substances outside cells, flagella are whiplike extensions found on sperm cells
• Centrioles


  Pairs of microtubular structures, play a role in cell division
• Nucleus


  Control center of cell, contains chromosomes and nucleolus
• Chromosomes


  DNA, proteins, form for cell division, chromatin
• Membranous Organelles


  • Lysosomes
  • Endoplasmic Reticulum
  • Golgi Apparatus
  • Vacuoles
• Lysosomes


  Contain digestive enzymes, digest excess or worn out organelles, food particles, and engulfed viruses or bacteria
• Endoplasmic Reticulum


  Helps move substances within cells, network of interconnected membrane, rough ER and smooth ER
• Golgi Apparatus


  Packaging and shipping station of cell, involved in synthesis of carbohydrates and lipids
• Vacuoles


  Membrane bound storage sacs, more common in plants than animals
• Mitochondria


  Have their own DNA, bound by double membrane, break down fuel molecules and release energy
• Chloroplasts


  Derived from photosynthetic bacteria, store solar energy
• Eukaryotes are multicellular organisms, Prokaryotes are unicellular organisms
• Eukaryotic/Prokaryotic describes the cell type, Eukaryote/Prokaryote describes the organism
• Leaf cell, Root hair cell, Yeast, Bacterial cell

  • Leaf cell absorbs light energy for photosynthesis, Root hair cell absorbs water and minerals, Yeast is a single-celled organism, Bacterial cell has different structure to animal or plant cell
• Cell membrane


  Membrane made of two layers of phospholipids with embedded proteins, separates the inside of the cell from its environment
• Components of cell membrane

  • Phospholipid bilayer
  • Proteins
  • Carbohydrates
  • Cholesterol
• Phospholipid


  Consists of a phosphate group (hydrophilic head) and fatty acids (hydrophobic tail)
• Types of membrane proteins

  • Integral (transmembrane or monoprotic)
  • Peripheral
• Functions of membrane proteins

  • Receptor
  • Channel
  • Transmembrane transport
  • Adhesion
  • Cell-cell recognition
  • Enzymatic function
• Carbohydrates


  Biomolecule made of carbon, hydrogen, and oxygen, found mostly on the external surface of the cell membrane
• Types of carbohydrates


  • Glycoproteins
  • Glycolipids
• Cholesterol


  Type of lipid, essential in production of other biomolecules, regulates fluidity of membrane
• Fluid mosaic model


  Describes the cell membrane as having a phospholipid bilayer with embedded proteins, carbohydrates, and cholesterol
• Functions of cell membrane

  • Protection
  • Material transport
  • Cell shape
  • Compartmentalization
  • Cell recognition
  • Cell function
• Cell cycle

  Series of events that occurs in a cell from one division to the next
• Phases of cell cycle

  • Interphase (G1, S, G2)
  • Mitotic (M) phase (Prophase, Metaphase, Anaphase, Telophase, Cytokinesis)
• Interphase


  Cell increases in size and volume, produces carbohydrates, lipids, proteins, and enzymes in preparation for S and M phases