Cell Biology: Cell biology is the study of cell structure
and function. All living organisms are composed of cells.There are two primary
types of cells: eukaryotic and prokaryotic cells. Eukaryotic cells have a
defined nucleus, while the prokaryotic nucleus is not defined or contained
within a membrane. While all organisms are composed of cells, these cells
differ among organisms. Some of these differing characteristics include
cell structure, size, shape, and organelle content. For example, animal cells, bacterial
cells, and plant cells have similarities, but they are also noticeably
different. Cells have different methods of reproduction. Some of these methods
include: binary fission, mitosis, and meiosis. Cells house an organisms genetic
material , which provides instructions for all cellular activity.
Important Events in the Discovery of Cells
1665 -
Robert Hooke looks at cork under a microscope. Named them as "cells"
1665 - 75 Anton Van Leeuwenhoek invented microscope
studies organisms living in pond water . He calls them
"Animalcules."
1830 -
German scientists Schleiden and Schawann summarize the
findings of many scientists and conclude that all living organisms are made of
cells. This forms the basis of the Cell Theory of Biology
in vivo means inside organism or cell
·
Principles of the Cell
Theory
·
A. All living things are made of one or more cells .
·
B. Cells are the basic unit of structure &
function in organisms.
·
C. Cells come only from the reproduction of
existing cells.
D.All
organisms are composed of cells.
Types of cells ,Prokaryotes ,Archaea and Eukaryotic CellDifference Between Prokaryotes and EukaryotesDifference between plant and animal cellsCell OrganellesCell CyclesChromosomes and chromatin structureCell DivisionMitosisMeiosisEukaryotic Gene and Gene Expression |
· Cell Diversity
· 1. Not all cells are alike
· 2. Cells differ in size, shape, and function
· 3. The female egg cell is the largest cell
in the body & can be seen without a microscope
· 4. Bacterial cells are some of the smallest
cells & are only visible with a microscope
· 5. Cells need surface area of their cell
membrane large enough to adequately exchange materials with the environment
(wastes, gases such as O2 & CO2, and nutrients)
· 6. Cells are limited in size by the ratio between their outer surface
area & their volume
· 7. Small cells have more surface area for their
volume of cytoplasm than large cells
· 8. As cells grow, the amount of surface area
becomes too small to allow materials to enter & leave the cell quickly
enough
· 9. Cell size is also limited by the amount
of cytoplasmic activity that the cell’s nucleus can control
