|
|
| (20 intermediate revisions by 6 users not shown) |
| Line 1: |
Line 1: |
| Living organisms can be sorted into two groups; these are the [[Prokaryotes]] and the eukaryotes. Eukaryotes are organisms that contain cells with a membrane-bound nucleus as well as membrane-bound [[Organelles]]. Examples of eukaryotes include all [[Animal|animals]], [[Plant|plants]], [[Fungi|fungi]] and protists. Eukaryotes may variably be multicellular or unicellular. Conversley, [[Prokaryotes]] contain no nucleus, no membrane bound organelles and the majority are known to be unicellular, very rarely are they multicellular. Examples of prokayotes are, [[Bacteria|bacteria]] and [[Cyanobacteria|cyanobacteria]]
| | See [[Eukaryote|Eukaryote]] |
| | |
| = Cell Structure =
| |
| | |
| *'''<u>Plasma Membrane</u>''':
| |
| | |
| [[Plasma membrane|Plasma membranes]] protect the internal parts of the cell from the environment. [[Proteins|Proteins]] and [[Lipid|lipids]], importantly [[Phospholipid]]s, make up the majority of the plasma membrane. The lipids are arranged in a fluid bilayer, with protein embedded which control the movement of [[Molecule|molecules]] and [[Ions|ions in]] and out of the [[Cell|cell]].
| |
| | |
| *<u>'''[[Cytoplasm|Cytoplasm]]:'''</u>
| |
| | |
| May also be referred to as the [[Cytosol|cytosol]]. This is a gel-like substance that is contained by the [[Plasma membrane|plasma membrane]], and within it is found all the [[Organelles|organelles]] of that cell.
| |
| | |
| *'''<u>[[Endoplasmic Reticulum|Endoplasmic Reticulum]]:</u>''''''<u></u>'''
| |
| | |
| There are two types of [[Endoplasmic reticulum|endoplasmic reticulum]]; [[Rough endoplasmic reticulum|rough]] and [[Smooth endoplasmic reticulum|smooth]]. [[Rough endoplasmic reticulum|Rough endoplasmic reticulum]], so called due to the [[Ribosomes|ribosomes]] found on its surface, synthesises [[Proteins|proteins]], and [[Smooth endoplasmic reticulum|smooth endoplasmic reticulum]] synthesizes [[Lipid|lipids]] and [[Carbohydrate|steroids]] and metabolizes [[Carbohydrate|carbohydrates]] and [[Steroids|steroids]]. The general structure is a network of sac-like structures called [[Cisternae|cisternae]], held together by the [[Cytoskeleton|cytoskeleton]].
| |
| | |
| *'''<u>Golgi Apparatus:</u>'''
| |
| | |
| The [[Golgi apparatus|Golgi apparatus]] gathers simple molecules and combines them to make molecules that are more complex which then get packaged them in [[Vesicles|vesicles]], and either stores them for later use or sends them out of the cell. It is builds [[Lysosome|lysosomes]]. The structure of the [[Golgi apparatus|Golgi apparatus]] can be described as a series of flattened sacs.
| |
| | |
| *<u>'''Mitochondria:'''</u>
| |
| | |
| [[Mitochondria|Mitochondria]] are vital organelles that provide energy for the cell to carry out all its functions, for example division. [[Mitochondria|Mitochondria]] have double membranes, with the outer membrane fairly smooth, and the inner membrane folded in to cristae, which greatly increases the surface area. It is on these cristae that sugar is combined with [[Oxygen|oxygen]] to produce [[ATP|ATP]] - the primary energy source for the [[Cell|cell]].
| |
| | |
| *<u>'''Nucleus:'''</u>
| |
| | |
| The [[Nucleus|nucleus]] controls all functions of the cell and contains genetic information in the form of [[DNA|DNA]], and its associated [[Proteins|protein]], [[Histones|histone]], which forms [[Chromosome|chromosomes]]. The [[Nucleus|nucleus]] is bounded by a double membrane, called the [[Nuclear envelope|nuclear envelope]]. Within the double membrane nuclear envelope are passages which large molceules can pass through called [[Nuclear pores|nuclear pores]]. Each Nucleus contains one or more nucleolus; the site of ribosome synthesis.
| |
| | |
| *<u>'''Cell Wall:'''</u>
| |
| | |
| [[Cell wall|Cell wall]] are present in [[Fungi|fungi]] and [[Plant cells|plant cells]], and exist around the outside of the [[Plasma membrane|plasma membrane]]. In [[Fungi|fungi]] [[Peptidoglycan|peptidoglycan]] forms the [[Cell wall|cell wall]] and in [[Plant|plants]], the strongest component of the cell wall is a [[Carbohydrate|carbohydrate]] called cellulose. Cells walls provide structural support and have no affect on the passage of [[Molecule|molecules]] and [[Ion|ions]] into and out of the [[Cell|cell]].<br>
| |
| | |
| = Reproduction =
| |
| | |
| The cell cycle of eukaryotic cells has two major phases: the [[Interphase|interphase]] and cell division. During the interphase, the [[Cell|cell]] takes in nutrients, grows, and duplicates its [[Chromosome|chromosomes]]. During the cell division phase, the nucleus divides in a process called [[Mitosis|mitosis]] and then the divided [[Nucleus|nuclei]] are established in separate cells in a process called [[Cytokinesis|cytokinesis]]. Each [[Daughter cell|daughter cell]] produced will be genetically identical to that of the [[Parent cell|parent cell]].
| |