CHAPTER 3 Highlights 67
Key Concepts
Study CHAPTER HIGHLIGHTS
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Key Terms
Section 1
light microscope (51)
electron microscope (51)
magnification (51)
resolution (51)
scanning tunneling
microscope (54)Section 2
cell theory (55)
cell membrane (56)
cytoplasm (56)
cytoskeleton (56)
ribosome (56)
prokaryote (57)
cell wall (57)
flagellum (57)
eukaryote(58)
nucleus(58)
organelle (58)
cilium (58)
phospholipid(60)
lipid bilayer (60)Section 3
endoplasmic reticulum (63)
vesicle (63)
Golgi apparatus (64)
lysosome (64)
mitochondrion(65)
chloroplast (66)
central vacuole (66)BIOLOGYBIOLOGY
Unit 1—Use this unit to review the key
concepts and terms in this chapter.Looking at Cells
Microscopes enable biologists to examine the details of cell
structure and to understand how organisms function.
Scientists use the metric system to measure the size of objects.
Light microscopes have a low magnification and can be used
to examine living cells.
Electron microscopes have a high magnification but cannot
be used to examine living cells.
The scanning tunneling microscope uses a computer to
generate a three-dimensional image of an object.Cell Features
The cell theory has three parts.
Small cells function more efficiently than large cells because
small cells have a higher surface-area-to-volume ratio than
large cells.
All cells have a cell membrane, cytoplasm, ribosomes, and DNA.
Prokaryotic cells lack internal compartments.
Eukaryotic cells have a nucleus and other organelles, as well
as a cytoskeleton of microscopic protein fibers.
The lipid bilayer of a cell membrane is made of a double
layer of phospholipid molecules.
Proteins in cell membranes include enzymes, receptor
proteins, transport proteins, and cell-surface markers.Cell Organelles
The nucleus of a eukaryotic cell directs the cell’s activities
and stores DNA.
In eukaryotic cells, an internal membrane system produces,
packages, and distributes proteins.
Mitochondria harvest energy from organic compounds to ATP.
Lysosomes digest and recycle a cell’s used components.
Plant cells have three structures that animal cells lack: a cell
wall, chloroplasts, and a central vacuole.