remember:

• An organelle is a subcellular structure that specific jobs to perform in the cell, they are membrane-bound structures within the cell.
• Compartmentalisation by organisation of structures within plasma membranes allows the development of specialised structures such as chloroplasts and mitochondria
• • only eukaryotic cells have membrane-enclosed organelles
• Compartmentalisation separates functions such as chemical reactions
• Advantages of compartmentalization:

  • Allows specific reactions to occur in specific locations
  • e.g. aerobic respiration in mitochondria
  • photosynthesis in chloroplasts
  • digestion in lysosomes
  • phagocytic vacuoles 
  • Nucleus and cytoplasm are separated
• Advantage of the organelles being separated from the cytoplasm:

  • The organelle can maintain its own internal environment.
• Significance of the separation of the nucleus and the cytoplasm in eukaryotic cells:

  • It allows for better regulation of gene expression
• What is a metabolite? 

  Metabolites are small molecules and are the intermediate and end-product molecules of metabolism. 

  end-product
• Main advantage is that the two stages of protein synthesis are physically separated

  1. Transcription - copying of DNA sequences onto mRNA
  2. Translation - conversion of mRNA sequence to amino acid sequence

  In eukaryotic cells, mRNA can be modified before translation which increases the number of proteins that can be made

  
• Clathrin helps to organise the formation of vesicles by assembling them into a lattice-like structure around the lipid membrane, thereby shaping the vesicle and aiding in its formation.

  them
• structure of the Golgi apparatus:

  Multiple stacked, flattened membrane-bound structures, many vesicles nearby. process proteins from rER. Most proteins are released from the cells or used in lysosomes for digestion.

  structure of ER:

  flattened membrane sacs called cisternae with ribosomes attached. Produces protein that will be released from the cell. Vasicle carry proteins to golgi apparatus for processing
• Free Ribosomes

  • synthesize proteins
  • mostly used for within the cells

  Bound Ribosomes

  • synthesize protein for export (secretion) from the cell
  • or for use in lysosomes, digestion of bacteria
• Advantages of double membranes:

  • Allow concentrations to be established between the inner and outer membranes
  • Inner surface area for proteins and reactions