cell organelles

• prokaryotic cells have no membrane bound organelles
• plasma membrane - protects cell from surroundings, semi permeable so regulates materials going in and out
• the nucleus is made up of:

  • nuclear envelope
  • nuclear pores
  • nucleoplasm
  • nucleolis
• nuclear envelope- double membrane which surrounds nucleus
• nuclear pores - allow passage of molecules
• nucleoplasm- makes up most of nucleus
• nucleolis- makes rRNA and ribosomes
• lysosome - destroy bacteria and damaged organelles through phagocytosis
• ribosomes are made of a small sub unit and a large sub unit
• ribosomes synthesise protein during translation
• smooth endoplasmic reticulum - make and store lipids and carbohydrates
• Rough endoplasmic reticulum - folds and processes proteins made by ribosomes
• mitochondria has a double membrane
• mitochondrias inner folds called cristae. matrix is inside cristae for respiration
• mitochondria is where ATP is produced
• chloroplasts have a double membrane
• chloroplasts have thylakoid membranes which stack to make grana and grana are linked together by lamellae
• golgi apparatus - makes processes and packages new lipids and proteins and makes lysosomes
• golgi vesicles - stores lipids and proteins and transports them out of the cell
• cell wall made of cellulose and chitin in fungi
• cell wall supports cell and prevents it from changing shape
• vacuole helps maintain pressure inside the cell and contains sap
• prokaryotic cells have 70s ribosomes while eukaryotic have 80s ribosomes
• cell fractionation - process of breaking open cells and separating organelles
• homogenisation practical:

  • stage 1-homogenisation
  • 1 - cells broken up in a homogeniser (blender)
  • filter homogenate to remove debris
  • stage 2- ultra centrifugation
  • spin in centrifuge at different speeds
  • fluid at top (supernatant) removed
  • heaviest organelle goes to bottom