UNIVERSITI TEKNOLOGI MARA CAWANGAN SARAWAK KAMPUS MUKAH
FACULTY OF PLANTATION AND AGROTECHNOLOGY
DIPLOMA IN PLANTING INDUSTRY MANAGEMENT
PROGRAM CODE: AT110
COURSE CODE: AGR122
COURSE NAME: PLANT SCIENCE
TASK NUMBER: 2.A.3
TASK TITLE: CELL REPORT 2
DATE OF ASSIGNMENT: 11/10/2018
DATE OF SUBMISSION: 14/10/2018
NAME: ODILIA ANAK JAMES
STUDENT ID: 2018696958
LECTURER: MOHAMAD IZWAN BIN ISMAIL (DR.)
CELL REPORT 2
THE FUNCTION OF THE ORGANELLES SUCH AS NUCLEUS, CLOROPLAST AND MITOCHONDRIA
Nucleus is the most important organelle in plant cell as in animal cell. Nucleus contains genetic material of eukaryotic cell. The nucleus is a membrane-bound organelle that contains most of cell genetic material. The interior of the nucleus does not contain any membrane-bound organelles or compartments. The content is not uniform and consists of a several of sub-nuclear bodies such as nucleolus. The genetic material in the nucleus is organized as multiple linear DNA molecules combined with various of proteins to form chromosomes. The genes with these chromosomes are the cell’s nuclear genome. The function of the nucleus is to maintain integrity of the genes and to control the activities of the cell by controlling the expression of the gene. The nucleus can also be considered as center which can control the cell.
Nucleus consists of 4 parts which are nuclear pore, nuclear envelope, nucleoplasm and nucleolus. Each part has their own function and importance. The nuclear membrane consists of two lipid bi-layers, the inner nuclear membrane, and the outer nuclear membrane. Nuclear membrane has its own function which is to separate the nucleus and nucleolus from the rest of the cell contents. The nuclear membrane is embedded with specialized proteins called nuclear pores which act as special gateway that allowing substances such as nutrients, waste, and cellular information to pass into and out of the nucleus. Nuclear pores are hollow protein structures that penetrate the nuclear membrane and act as doorways between the nucleus and cytoplasm. They allow small molecules and ions to freely pass into or out of the nucleus, but also may allow larger protein to enter the nucleus from cytoplasm if the proteins have special sequences. It indicates that that they belong in the nucleus. In the same way as proteins are allowed to enter, RNA transcribed in the nucleus, and proteins destined to enter the cytoplasm, have exports sequences that tag them for release through the nuclear pores. The nucleolus is a dense, spherical, non-membrane-bound structure found in nucleus of the cell. It is consists of primarily of proteins and nucleic acids. Its main function is to synthesize ribosomal RNA and combine it with proteins to form ribosomes. The nucleolus also can capture and immobilize proteins, thereby preventing cellular interaction with their binding partners. This helps regulating their cellular activity. Chromosomes are the bundles form of the DNA strands. Inside each human cell there is approximately 6 feet of DNA existing as 46 chromatin strands. Normally, this DNA is dispersed in a somewhat loose configuration, however, when the cell is preparing to divide, each strand of DNA condensed by a factor of 10000 times into a structure called a chromosomes. This folding and repackaging serves to facilities the process of cell division. When the cell divides, the chromosomes separate, providing a complete copy of the genetic information to each cell. The function of Chromatin is to efficiently package DNA into a small volume to fit into nucleus of cell and protect DNA structure and sequence. Packaging DNA into chromatin allows for mitosis and meiosis, prevents chromosome breakage and control gene expression and DNA replication.
Chloroplasts are structures in plant cells that contain large amounts of chlorophyll. Chloroplasts play an important role in the process of photosynthesis and convert light from sun to chemical energy (carbohydrates) for plants. Although not all the cells in the plant contain chloroplasts, it is contained in all parts of the green plant. The chlorophyll found in chloroplast which will give a plant its green colour. Chloroplasts circulate within plant cells and are greatly affected by light. When conducting photosynthesis, a chloroplast takes light energy from the sun and converts it to chemical energy. This process results in plants producing oxygen and other essential nutrients that a plant needs to survive. In addition to being a part of process of photosynthesis, chloroplasts have several important functions. This function includes producing of amino acids and fatty acids, and the reaction of a plant’s immune system.
A plant cell can contains various of chloroplast in it. For example, algae may only have one chloroplast, while a plant like wheat may have up to 100. Even though chloroplasts are an important part of a plant cell, the cell itself cannot produce them and they must be passed from one cell to another during cell division.
Chloroplasts are available in the cells of the mesophyll in plant leaves. Usually there are 30-40 per mesophyll cell. Chloroplast has inner and outer membrane with intermediate space in between. Inside the chloroplast, there is an arrangement of thylakoids, called grana and stroma, dense fluid inside the chloroplast. Thylakoids contain the chlorophyll that is needed for plant to go through process of photosynthesis. Chlorophyll filled space is called the thylakoid space.
The role of chloroplasts in photosynthesis is mainly contains most of the reaction during photosynthesis. The plant will pump water into the leaves, and the leaves will absorb carbon dioxide. All of the thylakoids, chlorophyll, water, carbon dioxide and so on can be found in chloroplast. The whole process of photosynthesis starts and completes inside of the chloroplast. Chloroplast basically works as the ‘powerhouse’ for the cell, similar to the mitochondria, except that it produces its own food which is then used to power the plant.
A mitochondrion is an organelle, a specialized structure found inside almost all eukaryotic cells. Eukaryotic cells contain a nucleus and membrane-bound organelles, like mitochondria. Mitochondria have been called the powerhouse of the cell because of their role in cellular respiration and energy production. Without mitochondria, we would not able to properly use our energy and live.
The major role of mitochondria is to produce energy currency of cells, ATP (i.e., ADP phosphorylation), through respiration, and to regulate cell metabolism. The set of reaction that is involved in the ATP production is known as the citric acid cycle, or the Krebs cycle. They convert sugar into adenosine triphosphate (ATP) and enzymes associated with cell metabolism. Mitochondria are special because they are surrounded by two membranes and contain their own independent genome. They also can divide independently of the cell in which they reside, meaning that mitochondrial replication is not tied to cell division. The amount of mitochondria in cell depend on how much energy that cell need to produce. The more energy a cell need, the more mitochondria it will have. For example, muscle cells have many mitochondria because they need to provide energy to move the body. Red blood cells, which carry oxygen to other cells, have none; they don’t have to produce energy. This show that any cells may contain only one mitochondria, while others may contain as many as several thousand. Mitochondria are present in both plants and animal cells.
Mitochondria are perfectly formed to maximize their productivity. They are made of two membranes, an outer membrane and an inner membrane which made of phospholipid layers. The outer membrane covers the surface of the organelle, while the inner membrane is located within and has many folds called cristae. The inner membrane is loaded with proteins involved in electron transport and ATP synthesis. The membrane surrounds the mitochondrial matrix, where the citric acid cycle provides electrons that travel from one protein complex to the next inner membrane. Thus, the fluid contained in the mitochondria is called the matrix. Mitochondria are very special because they have their own ribosomes and DNA floating in the matrix. The inner membrane fold increases the surface area inside the organelle. Due to the fact that many chemical reactions occur on the internal membrane, the rising surface area creates more space for the reaction to occur. If you have more space to work, you can get more work. A similar surface area strategy is used by microvilli in your gut.
As a conclusion, nucleus is basically plays an important role among eukaryotic organelle because it is the location of a cell DNA. Two other important organelles are mitochondria and chloroplast, which play important roles in energy conversion which is chloroplast convert sunlight into food during photosynthesis, then mitochondria produces energy out of the food in the form of ATP whereby critical chemical reactions occur in the cell that allow for the release of energy from food.