Lysosomes, Peroxisomes and Vacuoles Flashcards
what membrane bound sac containing acid hydrolases is created by the addition of hydrolytic enzymes to early endosomes from the golgi apparatus?
lysosomes
what is the term for when lysosomes digest excewss or worn out organelles?
autophagy
what organelles fuse with and dispense enzymes into vacuoles to digest their contents?
lysosomes
which organelles heal cell membranes by providing a ‘membrane patch’
lysosomes
which organelles are nicknames suicide bags or suicide sacs due to their role in autolysis?
lysosomes
if enzymes leak into the cytosol from lysosomes why is cell damage reduced?
whent the enzymes mix with the cytosol the pH is altered to a non optimum level
which is more acidic, the interior of a lysosome or the surrounding cytosol?
interior of lysosome
why is it important for the enzymes in lysosomes to be separated from the cytosol
so that the digestive enzymes can work optimally due to requiring a lower pH
how does the lysosome gain a lower pH than the surrounding cytosol?
proton pump and chloride ion channel facilitated H+ transfer
nucleases, proteases, glycosidases, lipases, phosphatases, sulfatases and phospholipases are examples of what
acid hydrolases
what are the three pathways leading to lysosomes?
phagocytosis
endocytosis
autophagy
what is the name of the membrane bound organelle containing a urate oxidase core?
peroxisomes
what organelle participates in the metabolism of fatty acids and other metabolites?
peroxisomes
which organelle contains enzymes that rid cells of toxic peroxides?
peroxisomes
which organelle contains enzymes that oxidise alcohol?
peroxisomes
which organelle contains enzymes that oxidise toxic products
peroxisomes
which organelle contains enzymes that generate h2o2?
peroxisomes
what does catalase do?
uses H2O2 to oxidise other substances
H2O2 + R1H2 —CATALASE—>
R1 + 2H20
RH2 +O2 —PEROXISOMAL OXIDASE–>
R1+ H2O2
Which enzyme uses H202 to oxidise substrates such as phenols, formic acid, formaldehyde and alcohol?
catalase
what disease causes children to be born with ‘empty’ peroxisomes due to enzymes failing to be imported into the organelles?
Zellwegers syndrome
what can peroxisomes do that mitochondria cannot?
regulate 02 tension in the cell
what lipid constituting 80-90% of the lipid in myelin sheath is synthesised by peroxisomes
plasmalogens
what molecule contains a fatty alcohol, fatty acid, and polar head group attached to a glycerol backbone by an ester linkage?
plasmalogen
what is the membrane of the vacuole called?
tonoplast
what organelle do plants typically have large versions of that animal cells either lack or have significantly smaller ones?
vacuoles
what is a vacuole
a membrane bound compartment that can serve a variety of secretory, excretory and storage functions, also provides turgidity to plant cells
what type of vacuole is used by some protists and macrophages as a stage in phagocytosis and is also called a storage sac?
food vacuoles
what type of vacuole is used to pump excess water out of the cell to reduce osmotic pressure and prevent bursting (cytolysis or osmotic lysis)
contractile vacuole
why does the vacuole push cell contents against the membrane in plant cells?
to keep chloroplasts closer to the light
what organelle stores pigments in flowers and fruits?
vacuole
what organelle is involved in exocytosis and endocytosis?
vacuoles
what type of endocytosis happens when material contacts the membrane and is invaginated, leaving engulfed material in a membrane enclosed vacuole and cell membrane intact?
phagocytosis
what mode of endocytosis in which small particles suspended in extracellular fluid are brought into the cell through an invagination of the cell membrane, resulting in a suspension of the particles within a small vesicle
pinocytosis
