Eukaryotic cells

• Prokaryotes vs Eukaryotes:

  • Pro = before, Karyote = nucleus
  • Prokaryotes don’t have a nucleus because they came before it evolved
  • They don’t have any membrane-bound organelles
• Nucleus:

  • Largest organelle
  • Structure: Nuclear envelope (double membrane with nuclear pores), nucleoplasm full of chromatin, nucleolus (dark centre) makes ribosomes
  • Function: Controls the cell's activities by controlling transcription of DNA
• Mitochondria:

  • Double membrane structure with outer membrane, matrix, inner membrane, and cristae
  • Produce ATP during aerobic respiration, folds are called cristae where respiration enzymes are found
  • Found in cells that require lots of energy for processes like active transport in intestine or muscle cells
• Smooth Endoplasmic Reticulum (SER):

  • Tubular structure with spaces
  • Involved in lipid synthesis and processing
  • "Smooth" because it doesn’t contain ribosomes
• Rough Endoplasmic Reticulum (RER):

  • A series of interconnected, flattened sacs
  • Have ribosomes attached and appear as dark blobs
  • Involved in folding and processing of proteins made by ribosomes
• Golgi Apparatus/Body:

  • A factory part of a cell that takes proteins from RER and free ribosomes, and lipids from SER to process, modify, and package them, including lysosomes
  • Processed molecules bud off in vesicles, used in the cell or leave by exocytosis
• Ribosomes:

  • Site of protein synthesis, translating mRNA into proteins
• Centrioles:

  • Important for the accurate separation of chromosomes during cell division, creating spindle fibers
• Lysosomes:

  • Spherical sacs containing digestive enzymes (lysozymes)
  • Involved in the breakdown of invading cells/foreign material or worn-down parts of cells
• what are the inner folds of mitochondria called?

  Cristae