Animal and Plant Cells

• Animals are eukaryotes - their genetic material is enclosed in a nucleus
• All cells have structures inside them - these are called sub-cellular structures
• Sub cellular structures inside an animal cell

  • Nucleus 
  • Cytoplasm 
  • Cell membrane 
  • Mitochondria 
  • Ribosomes

  
• Plant cells have a regular structure
• Sub cellular structures inside a plant cell

  • Nucleus 
  • Cytoplasm 
  • Cell membrane 
  • Mitochondria 
  • Ribosomes 
  • Cell wall 
  • Permanent vacuole 
  • Chloroplasts

  
• Role of the nucleus

  The role of the nucleus is to enclose the genetic material
• Role of the cytoplasm

  • The cytoplasm is a watery solution where chemical reactions take place 
  • An example of this is the first stage of respiration
• Role of the cell membrane

  The cell membrane controls the molecules / substances that can enter and leave the cell
• Role of the mitochondria

  The mitochondria is where aerobic respiration takes place
• Role of the Ribosomes

  • Ribosomes are where proteins are synthesised (made) - proteins are very important and carry out lots of functions in cells e.g. enzymes
  • Ribosomes are extremely small so cannot be seen with a light microscope 
  • Instead , a much more powerful microscope has to be used , called an electron microscope
• Role of the chloroplasts

  • Chloroplasts contain chlorophyll 
  • Plants need to make their own food , so some of their cells contain chloroplasts 
  • Chloroplasts are the site of photosynthesis , and absorb light to make food
• Root cells

  • Not all plant cells have chloroplasts
  • For example , they are not present in root cells because they do not receive any light 
  • Because root cells do not receive this , they do not need to photosynthesize to make food
• Role of the cell wall

  • The cell wall is made from a chemical called cellulose 
  • This chemical strengthens the cell
• Role of the permanent vacuole

  • The vacuole is filled with a fluid called cell sap 
  • The vacuole supports the plant and gives it its shape
• The theory of endosymbiosis states that 1.5 billion years ago, some early eukaryotes (the ancestor cells of animals and plants) engulfed bacterial cells and kept them prisoner inside their cells. They did this to harvest the sugars the bacterial cells were producing. The bacterial cells used light to produce sugars from carbon dioxide and water. Eventually these engulfed bacteria became which type of organelles?

  Chloroplasts