Читать книгу Cell Biology - Stephen R. Bolsover - Страница 31

1 All living organisms are made of cells.

2 There are only two types of cells, prokaryotic and eukaryotic.

3 Prokaryotic cells have little visible internal organization. They are usually 1–2 μm in size.

4 Eukaryotic cells usually measure from 5–100 μm. They contain a variety of specialized internal organelles, the largest of which, the nucleus, contains the genetic material.

5 The endosymbiotic theory proposes that some eukaryotic organelles, such as mitochondria and chloroplasts, originated as free‐living prokaryotes.

6 In multicellular organisms, cells are organized into tissues. In animals there are four tissue types: epithelium, connective tissue, nervous tissue, and muscle.

7 The extracellular matrix is found on the outside of animal cells.

8 In tissues, specialized cells arise from unspecialized stem cells.

9 Light microscopy revealed the diversity of cell types and the existence of the major organelles, such as the nucleus and mitochondria.

10 The electron microscope revealed the detailed structure of the larger organelles and resolved the cell ultrastructure, the fine detail, at the nanometer scale.

11 Fluorescence microscopy can reveal the location of specific molecules within the cell by using antibodies or genetically encoded fluorescent chimeras.

12 Super‐resolution microscopy is an advanced form of fluorescence microscopy that can reveal objects tens of nanometers in size.

13 Cells can be engineered to express fluorescent proteins that reveal many aspects of cell organization and behavior.