Cell Organelles

• Ribosomes is the site of protein synthesis and are made of RNA. Does not have a membrane.
• The smooth endoplasmic reticulum makes lipids and consists of flattened membrane bound sacs called cisternae.
• The rough endoplasmic reticulum transports proteins, has ribosomes bounded to the surface and consists of flattened membrane bound sacs called cisternae.
• the golgi appratus receives proteins from the endoplasmic reticulum, modifies them then transports the protein. The stack of membrabe bound flattened sacs are cisternae.
• The plasma membrane controls which substances can enter and leave the cell
• The nucleolus produces RNA and ribosomes
• Chloroplast is the site of photosynthesis and contains pigments of chloropyll.

  made up of stroma, granum, lamellae and thylakoid membrane
• The vacuole is membrane lined sacs in the cytoplasm containing cell sap. The membrane is called a tonoplast, which is selectively permeable
• The cytoskeleton is a network of fibres that holds the cell together, helps the cell to keep its shape and aids in movement.

  made up of:

  microfilaments - formed from actin for contraction/movement

  microtubules - determines shape of cell

  Intermediate fibres - mechanical strength to cells
• Lysosomes are specialised forms of vesicles, contain digestive enzymes that break down molecules and is surrounded by a singular membrane.
• The nucleus contains genetic material, contains chromatin, contains instructions on how to make proteins, surrounded by a nuclear envelope and has nuclear pores which allows molecules through.
• Mitochondria is where aerobic respiration takes place and where ATP is produced.
• Vesicles are small membrane sacs that specialise in moving products into and out of a cell.
• cell wall

  plants = cellulose (complex carbohydrate)

  animal = no cell wall

  prokaryotes = murein (peptidoglycan) (formed from amino acids and sugars)

  fungi = chitin
• centrioles - component of the cytoskeleton involved in the organisation of spindle fibres during cell division
• flagella - whip like enables cells motility, used as a sensory organelle detecting chemical changes
• cilia - mobile or stationary

  • function in organs like the nose
  • beat in rhythmic manner creating a current and causes objects to move e.g in the trachea to move mucus away from the lungs
• prokaryote vs eukaryote

  • nucleus present eukaryote
  • dna circular in prokaryote
  • dna linear in eukaryote
  • non membrane bound in prokaryotes
  • ribosome smaller in prokaryotes