BIOLOGY

• Biology


  The science of life and living organisms
• Cells


  The basic unit of life. All living organisms are either single cells, or are multicellular organisms composed of many cells working together
• Plant Cell


  • Cell Wall
  • Cytoplasm
  • Chloroplast
  • Amyloplast
  • Centrosome
  • Rough ER
  • Smooth ER
  • Ribosomes
  • Mitochondrion
  • Golgi Body
• Animal Cell


  • Cell Membrane
  • Vacuole
  • Nucleus
  • Nucleolus
  • Nuclear Membrane
  • Centrosome
  • Cytoplasm
  • Rough ER
  • Smooth ER
  • Ribosomes
  • Golgi Body
  • Mitochondrion
  • Lysosome
• Amyloplast


  An organelle in some plant cells that stores starch
• Cell Wall


  A thick, rigid membrane that surrounds a plant cell. It gives the cell most of its support and structure
• Cell Membrane


  A semi-permeable membrane that regulates the entry and exit of specific substances within the cell
• Centrosome


  A small body located near the nucleus that has a dense center and radiating tubules. It is where microtubules are made
• Chlorophyll


  A molecule that can use light energy from sunlight to turn water and carbon dioxide gas into sugar and oxygen (photosynthesis)
• Chloroplast


  An elongated or disc-shaped organelle containing chlorophyll. Photosynthesis takes place in the chloroplasts
• Cytoplasm


  The jellylike material outside the cell nucleus in which the organelles are located
• Golgi Body


  A flattened, layered, sac-like organelle that packages proteins and carbohydrates into membrane-bound vesicles for "export" from the cell
• Mitochondria


  The double-membraned organelles found in the cytoplasm of all eukaryotic cells that provide energy by breaking down carbohydrate and sugar molecules
• Nuclear Membrane


  The membrane that surrounds the nucleus
• Nucleolus


  An organelle within the nucleus where ribosomal RNA is produced
• Nucleus


  The spherical body containing many organelles, including the nucleolus. It controls many of the functions of the cell by controlling protein synthesis
• Ribosome


  Small organelles composed of RNA-rich cytoplasmic granules that are sites of protein synthesis
• Rough Endoplasmic Reticulum (Rough ER)


  A vast system of interconnected, membranous, infolded and convoluted sacks that are covered with ribosomes
• Smooth Endoplasmic Reticulum (Smooth ER)


  A vast system of interconnected, membranous, infolded and convoluted tubes that transport materials through the cell
• Vacuole


  A large, membrane-bound space within a plant cell that is filled with fluid and helps maintain the shape of the cell
• Lysosome or Cell Vesicles


  Round organelles surrounded by a membrane and containing digestive enzymes where the digestion of cell nutrients takes place
• Differences Between Plant and Animal Cells

  • Cell Wall (Present in Plants, Absent in Animals)
  • Chloroplast (Present in Plants, Absent in Animals)
  • Centricle (Absent in Plants, Present in Animals)
  • Lysosome (Absent in Plants, Present in Animals)
  • Vacuole (One large in Plants, Many/small in Animals)
• Cell Theory


  • All living organisms are composed of cells
  • Cells are the fundamental building blocks used to create tissues, organs, and entire functioning organisms
  • Cells arise from pre-existing cells (not spontaneous generation)
• Biomolecules


  • Carbohydrates
  • Fats/Lipids
  • Proteins
  • Nucleic Acids
• Carbohydrates


  Composed of carbon, hydrogen and oxygen. Their building blocks are monosaccharides
• Fats/Lipids


  A set of chemical molecules resulting from fatty acids that exhibit high solubility in apolar solvents (organic) and low solubility in polar solvents (water)
• Proteins


  A large class of biological molecules consisting of chains of amino acids
• Nucleic Acids


  A chain of nucleotides which stores genetic information in biological systems. It creates DNA and RNA which store the information needed by cells to create proteins
• Cells According to Complexity

  • Prokaryotic cells - simple, single-celled organisms without membrane-bound organelles or nucleus
  • Eukaryotic cells - contain a nucleus and organelles, and are enclosed by a plasma membrane
• Passive Transport


  Movement of ions and other atomic or molecular substances across cell membranes without need of energy input. Moves particles through the concentration gradient
• Active Transport


  Movement of molecules across a membrane from a region of their lower concentration to a region of their higher concentration. Particles move against the concentration gradient
• Diffusion


  Net movement of molecules from a region of high concentration to one of lower concentration
• Osmosis


  Process where solvent molecules move through a semipermeable membrane from a dilute solution into a more concentrated solution (which becomes more dilute)
• Mitosis


  A single cell divides resulting in generally two identical cells, each containing the same number of chromosomes and genetic content as the original cell
• Meiosis


  Reduces the chromosome number by half, creating four haploid cells, each genetically distinct from the parent cell that gave rise to them
• Botany


  The branch of biology that deals with the study of plants, including their structure, properties, and biochemical processes
• Types of Plant Cells

  • Parenchymal - cube-shaped, loosely packed, thin-walled, relatively unspecialized, contain chloroplasts
  • Collenchymal - elongated, irregularly thickened walls
  • Sclerenchyma - very thick cell walls containing lignin
• Plant Tissues


  • Meristematic tissues - mass of young, immature and undifferentiated cells that remain young and divide throughout the life of the plant
  • Permanent tissues - epidermis, periderm, vascular tissues (xylem and phloem)
• Different Plant Parts


  • Root
  • Stem
  • Leaf
  • Flower
  • Fruit
• Photosynthesis


  The process by which green plants and certain other organisms transform light energy into chemical energy