science bio

• Types of cells

  • Eukaryotic cells
  • Prokaryotic cells
• Eukaryotic cell


  Contains a membrane-bound structure called a nucleus and organelles
• Prokaryotic cell


  Lacks a nucleus and membrane-bound organelles
• Prokaryotic cells


  • Bacteria
  • Rickettsiae
• Cell theory


  • The cell is life's basic unit of structure and function
  • The cell is the smallest unit of living material that can carry out all activities necessary for life
• Light microscopes


  • Used to study stained or living cells
  • Can magnify up to 1,000 times
• Electron microscopes


  • Used to study detailed structure of a cell
  • Can magnify up to 250,000 times
  • Can only observe killed cells
• Plasma membrane


  • Regulates movement of substances into and out of the cell
  • Semi-permeable
• Nucleus


  • Control center of the cell
  • Home of hereditary information (DNA)
• Ribosomes


  • Sites of protein synthesis
  • Manufacture proteins required by the cell
• Endoplasmic Reticulum (ER)


  • Continuous channel extending into cytoplasm
  • Rough ER is studded with ribosomes
  • Smooth ER makes lipids and hormones
• Golgi bodies

  • Modify, process, and sort proteins
  • Packaging and distribution centers for materials
• Mitochondria


  • Powerhouses of the cell
  • Convert energy from organic molecules into useful energy (ATP)
• Lysosomes


  • Carry digestive enzymes
  • Break down old organelles and debris
• Centrioles


  • Active during cellular division
  • Produce microtubules to pull chromosomes apart
• Vacuoles


  • Fluid-filled sacs that store water, food, wastes, salts, or pigments
• Peroxisomes


  • Detoxify substances
  • Break down hydrogen peroxide
• Cytoskeleton


  • Network of fibers that holds the cell together
  • Determines cell shape
• Microtubules


  • Participate in cellular division and movement
  • Integral part of centrioles, cilia, and flagella
• Plant cells vs Animal cells

  • Plant cells have a cell wall
  • Plant cells have chloroplasts
  • Plant cells have a large vacuole
• Structural characteristics of different cell types

  • Cell Wall
  • Plasma Membrane
  • Organelles
  • Nucleus
  • Centrioles
  • Ribosomes
• Endocytosis is when the cell membrane engulfs large particles to form a vacuole or vesicle
• Cell metabolism

  1. Catabolism

  2. Anabolism
• Catabolism


  The cell breaks down complex molecules to produce energy
• Anabolism


  The cell constructs complex molecules and performs other biological functions
• Adenosine triphosphate (ATP)


  The energy molecule in the cell
• Energy cannot be created or destroyed
• The sum of energy in the universe is constant
• The second law of thermodynamics states that energy transfer leads to less organization
• Nutrient molecules processing

  1. Catabolism

  2. Anabolism
• Catabolism


  The cell breaks down complex molecules to produce energy and reducing power
• First law of thermodynamics

  Energy cannot be created or destroyed
• Second law of thermodynamics

  Energy transfer leads to less organization, tending toward disorder (entropy)
• Adenosine triphosphate (ATP)


  A molecule consisting of adenosine bonded to three phosphates, packed with energy
• Sources of ATP

  • Photosynthesis
  • Cellular respiration
• Photosynthesis


  The transformation of solar energy into chemical energy, producing glucose
• Photosynthesis stages

  1. Light reaction

  2. Dark reaction
• Light reaction


  Produces ATP and NADPH using sunlight
• Dark reaction


  Uses ATP and NADPH to make carbohydrates
• Cellular respiration


  Breakdown of nutrients to produce ATP