Cell Structure

• Parts of A Microscope:

  • Coarse Adjustment: Rough focus
  • Fine Adjustment: Precise focusing
  • Clip: holds slide in place
  • Stage: holds the slide
  • Condenser: focuses light onto the object
  • Eyepiece: Magnifies the image
  • Nose piece: Allows movement of different objective lenses
  • Objective lens: Magnifies the image
  • Diaphragm: controls the amount of light
• Ultrastructure is the fine detail of a cell seen with an electron microscope.
• Structure of a plant cell

  
• Structure of an animal cell

  
• Cell membranes are composed of phospholipids and proteins.
• Cell membranes retain cell content and control what enters and leaves the cell. (Selectively permeable)
• Mitochondria supply energy to the cell and function as a site for respiration.
• Many mitochondria are found in the muscle and liver.
• The nucleus is the control center of the cell. It contains strands of DNA (deoxyribonucleic acid) and is surrounded by a double membrane.
• Nuclear pores allow certain molecules to enter and exit the nucleus e.g RNA
• Ribosomes are made in the nucleolus. They consist of RNA and protein and their function is to make protein.
• Cell walls are made of cellulose and are fully permeable.
• Prokaryotic cells do not have a nucleus or membrane-enclosed organelles. e.g bacteria
• Eukaryotic cells have a nucleus and membrane-enclosed organelles. e.g humans