Cell organelles

• Eukaryotic cells have specialised organelles which facilitate biochemical processes
• There are many different organelles in cells
• Nucleus:

  • Acts as the 'control-centre' of the cell
  • Contains genetic material (DNA) packaged into chromosomes
  • Surrounded by the nuclear membrane with nuclear pores for material exchange
• Nucleolus:

  • Responsible for rRNA synthesis and ribosome biogenesis
• Mitochondrion (Mitochondria):

  • Site of cellular respiration, breaking down glucose to release energy
  • Double membraned and rod-shaped
  • Contains outer and inner membranes, matrix, and special proteins called porins
• Chloroplast:

  • Site of photosynthesis in plant cells
  • Contains chlorophyll for converting light energy into chemical energy
  • Only found in plant cells
• Vacuole:

  • Single membrane-bound sacs, larger and more common in plant cells
  • Functions as a storage facility for water, nutrients, and wastes
  • Maintains water-balance and shape retention in plant cells
• Golgi body (including vesicles):

  • Packages proteins, lipid molecules, and other materials into vesicles for transport
• Endoplasmic reticulum (rough & smooth):

  • Rough ER studded with ribosomes, packages proteins for transport
  • Smooth ER involved in detoxification and lipid synthesis
• Ribosome:

  • Site of protein synthesis, made up of proteins and rRNA
• Lysosome:

  • Contains hydrolytic enzymes for breakdown of non-functional organelles and cell debris
• Cytoskeleton:

  • Micro-filaments and microtubules that support and move organelles, maintain cell shape, and assemble spindle for cell division