ULTRASTRUCTURE OF CELLS
Electronic microscopes have a much higher resolution than light microscopes.
Note: The Electronic microscopes cost over 21 million dollars but with them you can see a much better resolution of the things observed in the microscopes.
Cells are small because of the surface area. The volume of the cells cant be that big because if not the organism cant metabolic the proteins and food, and it will take to long to process all the essential material for their function.
The Conversion of units:
1 meter= 10-0
1 centimeter = 10-2 meters
1 millimeter = 10-3 meters
1 micrometer = 10-6 meters
1 nanometer = 10-9 meters
PROKARYOTIC CELLS:
They divide by binary fision. They are smaller and have a simpler structure than the eukaryotics. They are also the earliest form of life in earth.
Cell wall: protects and maintain the shape of the cells.
Plasma membrane: controls the movements of the material in and out of the cell
Cytoplasm: all the cellular process in the prokaryotic cells occur in the cytoplasm, also regulate the liquid in the cell
Pili: used for attachments, they join bacterial cells to in preparation to transfer the DNA from one cell to the other.
Flagella: longer than the pili, it is used for cell motivity
Ribosomes: involved with the synthesis and creation of proteins
Nucleoid: contains DNA, cell control and reproduction
EUKARYOTIC CELLS: there are two types of this cells:
Cytoplasm: is where the functions of the cells expansion, growth, metabolism and replication are carried out
Endoplasmic Recticulum: transport of the material in the internal region of the cells it has 2 types:
Lysosomes: contain and transport enzymes
Golgi apparatus: collection, packaging, modification and distribution of the proteins
Mitochondria: they are organelles that has its own DNA and posses double membrane. Carries the respiration of the cells
Nucleus: contain DNA,it is often in form of chromosomes
Chloroplast: organelle that has its own DNA and double membrane (photosynthesis)
Centrosomes: allows movements and it is important for cell division
Vacuoles: storage food and water.
Endoplasmic Recticulum: transport of the material in the internal region of the cells it has 2 types:
- Rough: has ribosomes in the exterior and is involved with the synthesis of protein
- Smooth: production of the cell hormones, detoxification of drugs in the liver, storage calcium and transport.
Lysosomes: contain and transport enzymes
Golgi apparatus: collection, packaging, modification and distribution of the proteins
Mitochondria: they are organelles that has its own DNA and posses double membrane. Carries the respiration of the cells
Nucleus: contain DNA,it is often in form of chromosomes
Chloroplast: organelle that has its own DNA and double membrane (photosynthesis)
Centrosomes: allows movements and it is important for cell division
Vacuoles: storage food and water.
differences between prokaryotic cells and eukaryotic cells
- The prokaryotic cell has DNA without protein, the eukaryotic has DNA with protein in form of chromosomes
- The prokaryotic cells has 70s ribosomes, and the eukaryotic has 80s ribosomes
- The prokaryotic cells has a much simpler structure and it is smaller than the eukaryotic cells
- The prokaryotic cells have the DNA free in the cytoplasm, and the eukaryotics have the DNA inside the nucleous
- The prokaryotic cell dont have mitochondria, and the eukaryotics do have
differences between the plant cells and the animal cells
Plant cell
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Animal cell
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source: Pearson Baccalaureate, higher level Biology.
Theory of knowledge:
- The world that we inhabit is limited by the world that we see. Is there any distinction to be drawn between knowledge claims dependent upon observations made by sense perception and knowledge claims dependent upon observations assisted by technology?