Chloroplast Research Paper

Chloroplasts

Chloroplasts are a group organelles called plastids. The most primitive form of plastids are the progenitor of which, under the influence of sunlight formed chloroplasts. Chloroplasts are oval in shape and size of 3 to 10 nm. They contain photosynthetic pigments, among others chlorophyll carotenoids. Chloroplasts are covered with double cytoplasmic membrane. Inner membrane delimits a space, which is called steep. In the stroma they are flattened membranous vesicles (thylakoid) set on top of one another. The thylakoid membranes and stroma of photosynthesis take place in two stages: light and dark phase. The most important dye photosynthetic are chlorophylls that build the so-called. cents active thylakoids gran. The active center

takes place starting in the photosynthesis, ie. Killing of the electron of the chlorophyll molecule. During photosynthesis, carbon dioxide and water is generated, with the participation of the solar radiation, the organic matter in the form of glukozy. Other type of plastids are Chromoplast containing coloring agents which are not used in photosynthesis, but impart a characteristic color of flowers and fruits .Some of the plastids do not have dye and they are used to backup storage of substances, eg. leucoplast collecting starch. Chloroplasts, as mitochondria have their own DNA molecule, and therefore are also semi-autonomous organelles.
The Cell wall
The cell wall occurs in plant cells only, is situated on the cell membrane. The basic building block cell wall polysaccharide is cellulose-. Cellulose fibrils form a dense network that provides a rigid wall. Between the fibrils are voids (pores) of which the band onto the cytoplasm (plasmodesmata) providing contact between adjacent cells. The cell walls of plant cells provides immunity to mechanical injuries, protection from harmful germs and protects plants against excessive water loss.Organelle are elements of cells, each with a specific function for themselves. The smooth operation of these structures ensures proper functioning of the cell. The advanced development of modern biology can watch cell organelles under a microscope with a very high accuracy. The use of specific radiation or dyes allows for distinction and color of the structure of interest to us.
Cell membrane
The plasma membrane is composed of two primary components - lipids and proteins. In addition, it may consist of cholesterol and carbohydrates. The lipid content ranges from 25 to 70%. The model called the cell membrane. "Fluid mosaic" developed by Singer and Nicolson is the best model so far constructed. It shows the relationships and how to connect the membrane proteins and lipids.
Mitochondria
Mitochondria are organelles of a cylindrical shape of a size from 0.5 to 1 nm.

Their number, structure and shape depend on the type of tissue composed of cells. Most mitochondria present in the cell tissue with high activity, for example. Muscle. This is due to the fact that the mitochondria processes of cellular respiration of oxygen, which are the source of energy for cells. Mitochondrion is surrounded by two membranes: external and internal. The film has a large internal surface area, which creates corrugations within the organelle called combs. WnętrzeMitochondrium is defined as a matrix (matrix) and it contains ribosomes and mitochondrial DNA. Inner membrane exhibits poor permeability, in contrast to the outer membrane - highly permeable. Mitochondria are a kind of energy generators, because inside them, specifically in the membrane of the combs takes the second stage of aerobic respiration, or respiratory chain. The product of changes in the chain of energy is accumulated in ATP molecules. Mitochondria have their own DNA and therefore have the ability to produce its own proteins. Creating new mitochondria occurs through the division of existing mitochondria in the cell. Thanks to our own DNA mitochondria are organelles of a certain

autonomy.
Kernel
It is the most important cellular organelle, due to the fact that it contains a carrier of genetic information or genes. The kernel has a size of about 0.5 nm to 600 nm, is generally spherical in shape, although there are also clubbed and lenticular nuclei. As a rule, a single cell contains one nucleus. However, some cells contain more than one or do not have them at all(eg. sieve tubes of green plants, mammalian erythrocytes). Fungal cells have sometimes two nuclei lying next to each other, called nuclei coupled.
Some organisms (eg. Protozoa) have two nuclei with a different structure called micronuclei and macronuclei. The nucleus is surrounded by a double cytoplasmic membrane called the nuclear envelope. Between films, there is a narrow space, in some places these membranes links and create openings - nuclear pores. With these pores, it is possible to transport of certain molecules from both the nucleus to the cytoplasm, and vice versa. The outer membrane of the nuclear envelope is connected directly with endoplasmic reticulum located near the nucleus. Adjacent to the inner layer was laminated specific proteins that form the skeleton attitude nuclear envelope. White, these are extremely important in playing the envelope after cell division. Inside the kernel is koloid- karyolymph, which is suspended and chromatin.Chromatin core is a twisted strand of DNA linked with strongly basic histone proteins. DNA strands are very thin and long and they contain highly twisted packed in a regular manner -chromosome structure. In addition to histones, and the chromosomal DNA consists of more non-histone protein and RNA strands. Chromosomes are the condensed form of chromatin. On the other hand, there is also a form of loose - in the form of slightly twisted strands.
The chromosomes contain genes, which is an important genetic information.

During cell division, it is important for this information to reach to both daughter cells. The amount of chromosomes in the cells of progeny agreed with the number of chromosomes present in a cell of the parent is necessary amplification before distribution. After proliferation of each chromosome has a copy of which is connected so. telomere. At the time of the division of cells is observed in the condensation of chromatin into a short and thick chromosomes highly packed structure. Chromosomes in this embodiment can be observed in the

microscope.
The largest structure in the core is a core in the process for producing ribosomes. The core is not surrounded by a cytoplasm membrane or does not have a complicated structure. It contains special enzymes needed to produce ribosomes.

Question 2

Construction is the primary characteristic of the young, the peak sections of the stems of herbaceous plants and sections shoots of trees and shrubs.
The primary function is to keep the stems of leaves, flowers, fruits and intermediation in the distribution of nutrients, gathering up materials are also organs of assimilation (herbaceous plants). The result of the initial growth of the stem is to extend the momentum and the establishment of basic construction plan. Primary tissue stems arise from the activities of apical meristem. In angiosperms there are two basic plans for the construction of the original: monocotyledonous and dicotyledonous.
In the construction of the original distinguished successively skin - epidermis, cortex primary within which there is no vascular tissue, and an axial roller comprising a conductive beam.
The cells form a layer of skin covered with cutin, among them there stomata. Skin helps to maintain the cell turgor parenchymatous cylinder axis, because it protects against drying.
Bark original, filled with parenchyma contains chloroplasts and large intercellular spaces; a ventilation system of the plant. Are scattered in the sclerenchyma fibers and cells collenchyma, increase resistance to tearing. The last, deepest layer of cortex is endoderm - intradermally; its cells transport substances between the bark and roll.
The roller axle beam comprises a conductive complex phloem trees, arranged in a distinctive ring (dicotyledonous plants), or scattered throughout the stem (monocots). The arrangement of beams is always such that the bark is directed outside and inside of the stem wood.

Question 3

Secondary growth, growth of stem and root of the thickness of the wood due to the accumulation of secondary (toward the center) and the secondary phloem (the periphery) by the pulp creative (cambium) and an increase in secondary tissue. Secondary growth does not occur in most monocots. In plants, gymnosperms and angiosperms dicotyledonous roots grow between the thickness of the secondary side through meristem - cambium and fellogen.
Meristem cambium bands appear between the timber and the corrugated swallow as a shell, and form the center of the secondary wood elements (the inner side of the ring cambium), and outside the secondary phloem elements (on the outer side of cambium).
The entire root growth to a thickness that is within the cylinder axis, which it grows is disrupted layer cortex and rhizodermis. This process causes peeling of the primary root of the outer layers and the formation of secondary tissue covering - plug saturated impermeable to water and gases suberin. The growth of the secondary timber is substantially higher than secondary phloem, so grown root consists essentially of wood. On the basis of the secondary timber gain can be determined age of the trees. In monocots secondary growth occurs only in a few cases (eg. In dracaena, yucca), and its mechanism is different.