Chapter 3 Flashcards
I A M triangle
Image size/ Actual size X Magnification
Resolution definition
The ability to distinguish between two objects 
What is the buffer solution be like a cell fractionation?
Call to reduce enzyme activity, buffered to keep pH, the same, and the same water potential to prevent osmosis
What is homogenisation
So is that a broken by a homogeniser, resulting in the release of organelles from the sale, creating a liquid, called a homogenate
What is ultracentrifugation?
The process where organelles in homogenate, separated in a centrifuge by spinning the homogenate at different speeds
Describe ultracentrifugation
The tube of homogenate is placed in the centrifuge and spun at loose speeds, the heaviest organelles, like the nucleus sink to the bottom and form a thin sediment at the bottom. The supernatant is then removed, leaving just the sediment. The supernatant is then spun at a slightly quicker speed. The next heaviest organelle would sink to the bottom. The process is repeated until all organelles are separated out.
Order largest to smallest of organelles, separated in ultracentrifugation
Nuclei, chloroplasts, mitochondria, lysosomes, endoplasmic reticulum, ribosomes
Supernatant definition
The fluid left wants to sediment has collected after ultracentrifugation
4 stages of the cell cycle
Interphase, nuclear division, cell division
4 stages of mitosis
Prophase, metaphase, anaphase, telophase
Prophase
The chromosomes thicken, nuclear envelope disappears
Metaphase
Chromosomes move to the equator, spindle fibres attach to the centromeres
Anaphase
Spindle fibres contested, pulled apart to opposite poles
Telophase
Nuclear envelope appears around each chromatid, spindle fibres disintegrate, cell membrane starts to invaginate
Mitotic index
Number of cells undergoing mitosis/ Total number of cells observed
