Eukaryotic cells

• Light microscope 


  Is a tool that uses a beam of light and optical lenses to magnify specimens up to 1500 times life size
• electron microscope

  is a tool that uses a beam of electrons and magnetic lenses to magnify specimen up to 500,000 times life size
• Magnification 


  Is a measure of how much bigger the image you see is then the real object
• Resolution 


  Is a measure of how close together two objects can be before they are seen as one
• Transmission electron micrographs 


  Are micrographs produced by the electron microscope that give 2d images like those of a light microscope, but magnified up to 500,000 times
• Scanning electron micrographs 


  Are micrographs produced by the electron microscope that have a lower magnification then TEM’s, but produce a 3d image
• Organelles 


  Are sub-cellular bodies found in the cytoplasm of cells
• Eukaryotic 


  Are a group of organisms with cells that have the genetic material contained in a membrane-bound nucleus and also contain a number of membrane-bound organelles
• Prokaryotes 


  Are a group of organisms including bacteria that have a few organelles and do not have the genetic material contained in a membrane-bound nucleus
• Cell surface membrane 


  Is the membrane that forms the outer boundary of the cytoplasm of a cell and controls the movement of substances in and out of a cell
• Vesicle 


  Are membrane bags that hold secretions made In cells
• Polar lipids 


  Are lipids with one end attached to a polar group.
• Gated channels 


  Are protein channels through the lipid bilayer of a membrane that are opened or closed, depending on conditions in the cell
• Fluid mosaic model 


  Is the current model of the structure of the cell membrane including floating proteins forming pores, channels, and carrier systems in a lipid bilayer.
• Cytoplasm 


  Is a jelly like liquid that makes up the bulk of the cell and contains the organelles
• Nucleus 


  Is an organelle containing the nucleic acids DNA and RN, as well as protein, surrounded by a nuclear envelope with pores
• Protoplasm 


  Is the cytoplasm and nucleus combined
• Ultrastructure


  Is the detailed organisation of the cell, only visible using the electron microscope
• Intracellular


  Means inside the cell
• Chromatin 


  Is the granular combination of DNA bonded to protein found in the nucleus when the cell is not actively dividing
• Nucleolus 


  Is an extra dense area of almost pure DNA and protein found in the nucleus involved in the production of ribosome and control of growth and division
• Mitochondria 


  Are rod-like structures with inner and outer membranes that are the site of aerobic respiration
• Cristae 


  Are the infoldings of the inner membrane of the mitochondria which provide a large surface area for the reactions of aerobic respiration
• Eubacteria


  Are true bacteria
• Endosymbiotic theory 


  Is a theory that suggests that mitochondria and chloroplasts originated as independent prokaryotic organisms that began living symbiotically inside other cells as endosymbionts
• Centrioles 


  Are bundles of tubules found near the nucleus and involved in cell division by the production of a spindle of microtubules that move the chromosomes to the ends of the cell
• Spindle 


  Is a set of overlapping protein microtubules running the length of the cell, formed as the centrioles pull apart in mitosis and meiosis
• Cytoskeleton 


  Is a dynamic, 3D web like structure made up of microfilaments and microtubules that fills the cytoplasm and gives it structure, keeping the organelles in place and enabling cell movements and transport within the cell.
• Microfilaments 


  Are protein fibres that make up part of the structure of the cytoskeleton
• Microtubules 


  Are tiny proteins tubes about 20nm in diameter that make up part of the structure of the cytoskeleton
• Vacuole

  Is a fluid filled cavity within the cytoplasm of a cell surrounded by a membrane
• Contractile vacuoles 


  Are vacuoles that can fill and empty to help control the concentration of the cytoplasm of simple freshwater animals
• Endoplasmic reticulum 


  Is a 3D network of membrane bound cavities in the cytoplasm that links to the nuclear membrane and makes up a large part of the cellular transport system as well as playing an important role in the synthesis of many different chemicals
• 80s ribosome 


  Are the main type of ribosome found in eukaryotic cells, consisting of ribosomal RNA and protein, made up of a 60s and 40s subunit. They are the site of protein synthesis
• 70s ribosome 


  Are found in the mitochondria and chloroplasts of eukaryotic cells and in prokaryotic organisms
• Rough endoplasmic reticulum 


  Is endoplasmic reticulum that is covered in 80s ribosomes and is involved in the production and transport of proteins
• Exocytosis


  Is the energy requiring process by which a vesicle fuses with the cell surface membrane so the contents are released to the outside of the cell
• Smooth endoplasmic reticulum 


  Is a smooth tubular structure similar to RER, but without the ribosomes, which is involved in the synthesis and transport of steroids and lipids into the cell.
• Golgi apparatus 


  Consists of stacks of membranes that modify proteins made elsewhere in the cell and package them into vesicles for transport, and also produce materials for plant cell walls and insect cuticles
• Lysosome


  Is an organelle full of digestive enzymes used to break down worn out cells or organelles, or digest food in simple organisms