Prokaryotic cells

• Hypertonic solution 


  Is a solution with a higher concentration of solutes and lower concentration of water than the surrounding solution
• Peptidoglycan 


  Is a large, net like molecule found in all bacterial cell walls made up of many parallel polysaccharide chains with short peptide cross-linkages
• Pili 


  are thread like protein projections found on the surface of some bacteria
• Bacteriophages 


  Are viruses that attack bacteria
• Flagella 


  Are many stranded helices of the contractile protein flagellin found on some bacteria, they move the bacteria by rapid rotations
• Mesosomes 


  Are infoldings of the cell membrane of bacteria
• Nucleoid


  Is the area in a bacterium where we find the single length of coiled DNA
• Plasmids 


  Are small, circular pieces of DNA that code for specific aspects of the bacterial phenotype
• Gram staining 


  Is a staining technique used to distinguish types of bacteria by their cell wall
• gram-positive bacteria 


  Are bacteria that contain teichoic acid in their cell walls and stain purple/blue with gram staining
• teichoic acid 


  Is a chemical found in the cell walls of gram positive bacteria
• Gram-negative bacteria 


  Are bacteria that have no teichoic acid in their cell walls, they stain red with gram staining
• Cocci 


  Are spherical bacteria
• Bacilli 


  Are rod shaped bacteria
• Spirilla 


  Are bacteria with a twisted or spiral shape
• vibrios 


  Are comma-shaped bacteria
• facultative aerobes

  Are organisms that use oxygen if it is available, but can respire and survive without It
• Obligate aerobes 


  Are organisms that need oxygen for respiration
• Obligate anaerobes 


  Are organisms that can only respire in the absence of oxygen and are killed by oxygen
• Envelope 


  Is a coat around the outside of a virus derived from lipids in the host cell
• Capsid


  is the protein coat of a virus
• Capsomeres 


  Are the repeating protein units that make up the capsid of a virus
• Virus attachment particles 


  Are specific proteins (antigens) that target proteins in the host cell surface membrane
• DNA viruses 


  Are composed of DNA as the genetic material
• RNA viruses 


  Are composed of RNA as the genetic material
• Retroviruses 


  Are a special type of RNA virus that control the production of DNA corresponding to the viral RNA and insert it into the host cell DNA
• Reverse transcriptase 


  Is an enzyme synthesised in the life cycle of a retrovirus that makes DNA molecules corresponding to the viral RNA genome
• Pandemic 


  Is an epidemic that takes place in several countries at once