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The cell is the smallest unit of a living thing that shows all the characteristic properties of life, as distinguished from the surrounding environment (with its membrane), has a metabolism and can replicate itself (every cell comes from another previous cell).
The most important division between living things is not that between animals and plants, as you might think, but that of eukaryotes andprokaryotes. Because your organization more complex eukaryotic cells should appear after evolutionarily prokaryotes. According endosymbiotic theory, eukaryotes emerged from the association of several prokaryotic cells.
A eukaryotic cell is that having the core surrounded by a membrane that isolates the cytoplasm, i.e., which possesses a true nucleus, and other intracellular organelles, whichoccur in many cellular functions. While a prokaryotic cell lacking core and other membrane-bound organelles, although the physiological processes that are performed in these organelles, such as respiration and photosynthesis, can also occur in these cells.
UNIT 2: THE CELL. Structure and function.
Fig 1: prokaryotic cell.
AGENDA OF BIOLOGY. UNIT 2: THE CELL.
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Fig.2: eukaryotic plant cell.Fig.3: eukaryotic animal cell.
AGENDA OF BIOLOGY. UNIT 2: THE CELL.
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CHART
DIFFERENCES
PROKARYOTES
Cells EUKARYOTES small size generally large size cells scattered throughout the cytoplasm DNA (genóforo) DNA in the nucleus surrounded by a membrane Ribosome Ribosome 80 S 70 S (present in mitochondria and chloroplastsare 70 S) No cellular organelles organelles Division direct cell (no mitosis) cell division by mitosis without centrioles, and spindle microtubules with centrioles and mitotic spindle microtubules few multicellular forms. No forms are unicellular and multicellular tissues. The latter can be large differences in tissue metabolism Identical obtaining energy metabolism (glycolysis and Krebs cycle)2. Eukaryotic cell components.
There is a cell which can be considered typical and representative of all others. However, they all share common features which allow a model. The outer surface is limited by the cell or plasma membrane, which isolates the cell from the environment and through which incoming and outgoing nutrients and waste materials (chemical equilibrium controls). Inside is thenucleus, the control center of their activities (headquarters is genetic material DNA). The remaining volume corresponds to the cytoplasm. All components and the membrane enclosing substances are often given the generic name of protoplasm.
Plant and animal cells have in common, essentially three parts: the plasma membrane, cytoplasm and nucleus.
Animal cells are different from the first plantin which the energy obtained from food eaten by humans and animals. The centrio9los, directing mitosis, are unique to animal cells.
The elements (or organelles) typical of plant cells are:
- The cell wall, which is composed of cellulose and the membrane covering.
- Chloroplasts in which photosynthesis takes place.
- Vacuoles, that help store and remove metabolicproducts toxic products.
AGENDA OF BIOLOGY. UNIT 2: THE CELL.
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The component parts of the cell are:
1. Plasma membrane. Cell wall. 2. Cytoplasm • Cytoskeleton. Hyaloplasm. • Systems membranes and membranous organelles: - Endoplasmic reticulum: smooth and rough. - Golgi apparatus. - Lysosomes. - Peroxisomes or microbodies. - Vacuoles. - Mitochondria. - Chloroplasts.
• Organelle without membranousportions: - Ribosomes. - Centrioles
• cellular inclusions.
3. Core: • nuclear membrane. • Chromatin. Chromosomes. • Nucleolus.
2.1. Cell membranes: chemical composition and structure.
The cells may have different types of wraps but always membranes, basically laminar structures formed by lipid membranes. The extracellular matrix in animal cells and plant wall of vegetable cells are...