Ch 1

• Cell


  • The simplest collection of matter that can live
  • The fundamental unit of structure and function of all organisms
• Common features of all cells

  • Have ribosomes to synthesize proteins
  • Transform energy (ATP) to make ATP
  • Respond to external environment
  • Replicate and are relatively small
• Why cells are small

  Large surface area needed to absorb nutrients and release waste
• A small cell


  Can grow and divide faster than a large cell
• A small cell


  Evolves faster than a large cell
• Microscope


  Enabled the discovery of cells in 1665 by Robert Hooke
• Cell Theory


  • All living things are made of cells
  • All cells come from pre-existing cells by division
  • Cells contain genetic information (DNA) which is passed from cell to cell during division
• Prokaryotic cells


  • DNA is concentrated in the nucleoid
  • No membrane-bounded compartments (organelles) inside the cell
• Eukaryotic cells


  • DNA located in a nucleus surrounded by a membrane
  • Divided into membrane-bounded compartments called organelles, each with a specialized function
• Prokaryotic cells are smaller and structurally simpler than eukaryotic cells
• Five Kingdom System


  Grouped organisms based on morphological similarities like size, shape, function, nutritional requirements, cell structure
• Physical similarity does not always indicate relatedness
• Three Domain System


  Groups organisms based on genetic relationships and common ancestry
• Similarities between the three domains

  • Plasma membrane made of lipids
  • Use of ATP to transfer energy
  • DNA as genetic material
  • Ribosomes to make proteins
• Each domain (Bacteria, Archaea, Eukarya) is distinct
• Ribosomes are responsible for protein synthesis.
• Mitochondria generate energy through aerobic respiration.