Flashcards in Extra Bits To Know Deck (10):
What evidence is there that mitochondria evolved from prokaryotes?
Both have circular DNA in the form of a plasmid
Both have 70s smaller ribosomes
Both are double membrane bound
Where are enzymes produced?
In the rough endoplasmic reticulum
Why do cells produce inactive enzymes inside the cell?
So it doesn’t digest proteins within the cell
So cell doesn’t become damaged or destroyed
What are the steps of cell fractionation?
Preparing the sample
What is involved in preparing a sample for cell fractionation?
Sample kept cold - reduce enzyme activity to break down organelles
Buffered - so that the the pH doesn’t fluctuate and denature organelle s or enzymes
Isotonic - Sam water potential as the tissue to prevent osmotic or loss and this organelles bursting or shrinking
What is involved in fractionation?
Cells broken down in a blender which releases organelles from cell
Resulting fluid known as homogenate is the filtered to remove debris
What is the process of ultracentrifugation?
Filtrate placed in tube and spun at a low speed and heaviest organelles forced to the bottom as a pellet
Fluid at the top is removed and re-spun at a faster speed the next heaviest organelles are separated
What speeds are used in ultracentrifugation? What is produced?
Nuclei 1000 revs per min
Mitochondria 3500 revs per min
Lysosomes 16500 revs per min
Where are the main enzymes produced?
Amylase - salivary glands, pancreas and small intestine
Protease - stomach, pancreas and small intestine
Lipase - pancreas and small intestine