Chapter 7 (A Tour of the Cell)
Terms
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- open system
- organism that interacts and is affected by its environment
- light microscope (LM)
- basic microscope, light goes through specimen then lens then eye
- magnification
- how much larger an organism appears compared to its actual size
- resolving power
- clarity of image
- organelles
- subcellular structures
- electron microscope (EM)
- electrons pass through specimen
- transmission electron microscope (TEM)
- uses electromagnet lenses; focused onto a screen for viewing; used mainly for internal ultrastructure of cells
- scanning electron microscope (SEM)
- used mainly for detailed study of the surface of a specimen; 3D appearance: electrons become excited; specimen usually coated in gold
- cytology
- the study of cell structure
- What is the objective of cell fractionation?
- to separate organelles so functions can be studied
- ultracentrifuge
- most powerful kind of centrifuge (used in cell fractionation)
- homogenization
- disruption of cells (first step in cell fractionation)
- pellet
- large structures packed at bottom of test tube after being spun in centrifuge at various intervals of time
- supernatant
- smaller cell parts suspended in liquid above pellet
- What organisms are composed of prokaryotic cells? Eukaryotic?
-
prokaryotic: bacteria only
eukaryotic: all others - A prokaryotic cell does not contain a _____.
- nucleus
- nucleoid
- DNA is enclosed in this in prokaryotic cells (but there is no membrane between DNA and the rest of the cell).
- A eukaryotic cell has a ________ __________ enclosed in a _________ ___________.
- true nucleus enclosed in a membrane envelope
- cytoplasm
- region between nucleus and membrane
- cytosol
- makes up cytoplasm; semifluid in which organelles are suspended
- What is the relation in size between eukaryotic and prokaryotic cells?
- eukaryotic cells are 10 times larger (in general)
- plasma membrane
- selective barrier allowing oxygen, nutrients and wastes to pass into the cell in order to provide sufficient service to the cell
- A cell's surface area must be _______ than it's volume.
- larger
- What do internal membranes do?
- partition the cell into compartments
- Biological membrane have a double layer of ______________. ___________ are embedded into membranes.
-
double layer of phospholipids
proteins are imbedded in membranes (enzymes too)