lisosom Nama lysosome berasal dr kata Greek lysis,yg berarti

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lisosom
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• Nama lysosome berasal dr kata Greek lysis,yg
  berarti menghancurkan, and soma,yg berarti badan.
  
• Sering disebut "suicide-bags" or "suicide-sacs"
  krn berperan sebagai autolysis.
• Lysosomes ditemukan oleh orang Belgia
  (cytologist) Christian de Duve in 1949

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• organelles yg mengandung digestive enzymes (acid
  hydrolases).
• Ada pada semua sel eukariotik kecuali pd sel
  darah merah
• Banyak terdapat pd sel
• Enzim dibuat di retikulum endoplasma, dipaket di
  apparatus golgi
• Akan mencerna zat sampah, food particles, dan
  menelan viruses or bacteria.

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Membran lisosom

• Menyediakan pH asam bagi enzim hidrolitik
• Mempunyai pompa H
• Terdapat lysosomal-associated membrane protein
  (LAMP) sebagai penerima kantong vesikel pada
  lisosom

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• Macam Lisosom
• 1. Lisosom primer
• Hanya berisi enzim hidrolase
• 2. Lisosom sekunder
• Berisi enzim hidrolase dan substrat yg dicerna
• 3. vakuola pencernaan
• Fusi antara fagosom dan endosom dgn lisosom
  primer

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• Enzymes
• Lipase, which digests lipids,
• Carbohydrases, which digest carbohydrates (e.g.,
  sugars),
• Proteases, which digest proteins,
• Nucleases, which digest nucleic acids.
• Phosphatases, which digest phosphoric acid
  monoesters
• Lysosomal enzymes are synthesized in the cytosol
  and the endoplasmic reticulum, where they receive
  a mannose-6-phosphate tag that targets them for
  the lysosome.

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• Fungsi
• lisosom digunakan utk digesti macromolecules dr
• 1. phagocytosis (ingesti sel yg mati or material
  ekstraselular yg besar),
• 2. endocytosis (which receptor proteins are
  recycled from the cell surface), and
• 3. autophagy (organela, protein, mikroba yg
  mati dikirim ke lisosom).
• Autophagy juga sebabkan autophagic cell death, a
  form of programmed self-destruction, or
  autolysis, sel mendigesti dirinya sendiri.

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Receptor-Mediated Endocytosis
Receptor proteins make this a highly specific
form of transport.
Cholesterol is taken-up this way.
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Endocytosis Phagocytosis Transports Large
Particles
Endocytosis Phagocytosis Transports Large
Particles
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The Threshold of Phagocytosis - Capture of a
Yeast Cell (yellow) by Membrane Extensions of an
Immune System Cell (blue)
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• Fungsi lain
• memperbaiki kerusakan plasma membrane
• Berperan pada proses programmed cell death
  seperti pada pembentukan jari-jari fetus umur 3-6
  bulan (disebut apoptosis)

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The Lysosome
Functions
Digesting food or cellular invaders
Recycling cellular components
Cell suicide (suicide is bad for cells, but good
for us!)
(The lysosome is not found in plant cells)
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The Lysosome
This bacterium about to be eaten by an immune
system cell will spend the last minutes of its
existence within a lysosome.
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• Mekanisme pencernaan lisosom
• Bila yg dicerna berasal dr luar sel dsbt
  Heterofagi, jika dr dlm dsbt autofagi
• Proses pencernaan heterofagi trjadi scr
  endositosis---mbntuk endosom---melebur dengan
  lisosom primer---mebntuk lisosom sekunder---sisa
  pencernaan dikeluarkan dr sel dgn eksositosis.