Structure of eukaryotic cells

• What is an organelle?

  
  

  a distinct structure within a cell that completes a specific function
• What is the nucleus?

  
  

  - contains DNA which is the code for making proteins, wrapped around (associated with) histones

  - site of transcription (an mRNA copy of a gene is made)

  - site of DNA replication
• What is the nucleolus?

  
  

  Where ribosomes are produced from protein and rRNA
• What are ribosomes?

  site of protein synthesis
• What are mitochondria?

  
  

  -site of aerobic respiration

  -ATP is made here
• What is the rough endoplasmic reciculum?

  transports protein
• what is the smooth endoplasmic reticulum?

  
  

  Site of lipid and carbohydrate synthesis, storage and transport
• What is the Golgi body?

  
  

  - modifies and packages proteins

  - forms vesicles to transport molecules towards the cell surface

  - forms lysosomes
• What are vesicles?

  
  

  Sacs of chemicals that transport chemicals from the endoplasmic reticulum to the Golgi apparatus between Golgi cavaities and to the cell surface
• What are lysosomes ?

  
  

  -type of vesicle that contains enzymes

  - isolate enzymes from the rest of the cell before releasing them to the outside of the cell via exocytosis

  - or into the cell when it is damaged/no longer needed so that it is broken down
• Describe the structure of the nucleus

  • nuclear envelope that is a double membrane with pores within it
  • Chromatin/DNA associated with histones
  • Nucleolus which is the site of ribosome production