Cell organelles
Cells are incredibly complex and most complex cell would be a eukaryotic cell. It has many different organelles and each hold a specific job. Nucleus is very large and is controlling the whole system of the cell. The nucleus contains DNA in the form of chromosomes and is the site of synthesis of RNA. It is separated from the rest of the cell by a double membrane (envelop), which has pores to allow the movement of substances in or out. For example, messenger RNA passes out of the nucleus during protein synthesis. (Clamp, 2000, pg. 102) Endoplasmic reticulum is a system of membranes found in the cytoplasm of a cell. The ER provides a very large surface area for chemical reactions within the cell. It also acts as a pathway for
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There are two types of ER. One of them is Rough ER that has an outer surface lined with ribosomes and is involved in the synthesis of proteins and there is Smooth ER that has no ribosomes and is concerned with the synthesis of lipids and steroids. (Clamp, 2000, pg. 52) Ribosomes are spherical structures composed of ribosome RNA and protein, they are very small organelles and they act as a site of protein synthesis in a cell. They are found free in the cytoplasm and attached to ER (making it rough ER). (Clamp, 2000, pg. 128) Mitochondrion is known as the powerhouse of the cell it is a rod-shaped organelle and its main job is to release energy from carbohydrates into ATP. Mitochondrion is responsible for cell respiration. It has an interesting feature, the mitochondria has a double membrane where the internal membrane is folded up and this where the cell respiration takes place. Also mitochondria have own DNA and its own set of ribosomes. (Clamp, 2000, pg. 92) Another important organelle is a Golgi apparatus; it is a collection of membranes and vesicles. The Golgi body is an organelle with a number of functions, including the synthesis of glycoproteins; the secretion of enzymes and hormones; and the …show more content…
As a result cell becomes more efficient and becomes more specialized. Its chief function is to regulate and control what goes in and out of the cell. Plasma membrane is a double-layered structure. The plasma membrane has two main components: phospholipids and proteins. The phospholipids form two layers of molecules with their hydrophobic “tails” oriented away from the water and hydrophilic “heads” oriented toward the water. Proteins and substances as cholesterol are embedded in the membrane, and are able to move across the membrane, that’s why we call it fluid mosaic model. Only uncharged molecules such as water, carbon dioxide, oxygen and ammonia can pass through the membrane freely. Larger charged molecules like amino acids, sugars, and charged ions go through the cell membrane with the help of the proteins that are embedded in the membrane. (Alters and Alters, 2006, pg.
parts, and each part has its own job. The nucleus of a cell is very similar
This happens because the mitochondria now has more surface area connecting it to its surroundings. The processes that the mitochondria make are to break down the high energy organic molecules into smaller more useful packages. The endoplasmic reticulum is a network of tubes and channels that transport and with the help of ribosomes produce proteins. The rough endoplasmic reticulum contains ribosomes which are not present in the smooth endoplasmic reticulum.
Organelles work together to carry out life processes and functions. Each organelle has a certain responsibility to carry out. Organelles are always working diligently to maintain a cell’s internal process and functions. Firstly, the “brain” of the cell is the nucleus. The nucleus administrates all of the cell activities. And, found within the nucleus there is genetic material called chromosomes. Secondly, the nuclear membrane surrounds the nucleus. Additionally, the mitochondria makes ATP energy from food. The lysosomes has digestive enzymes that help break food down. Furthermore, the ribosomes make protein. Then, the Golgi apparatus process and package the
The most important and largest cellular organelle is the nucleus, which houses most of the eukaryotic cell’s DNA and is surrounded by a double membrane. The nucleus contains most of the cells genetic material. The nucleus is the control center of the cell.
Q1.The cell cycle is the series of events which occur in a cell leading to its division and replication.
Eukaryotic cells have their chromosomes contained in a nucleus. Unicellular orgasisms such as amoebas and yeast, or multi-cellular organisms such as plants and animals consist of eukaryotic cells. Human being consist of approximately 1 billion cells per gram tissue. DNA located in 23 pairs of chromosomes is contained in each cell nucleus. Schleiden in 1838 and Schwann in 1839 made very important discoveries that we consist of cells, and Remark discovered that cells prolifarate through division in 1850. Three decades ago, the molecular mechanisms that regulate the cell cycle and thus cell division was able to be identified. It has been known that these vital mechanisms are conserved through evolution and function in the same way in eukaryotic organisms.
The cell cycle is the process by which cells progress and divide. In normal cells, the cell cycle is controlled by a complex series of signaling pathways by which a cell grows, replicates it’s DNA and divides, these are called proto-oncogenes. A proto-oncogene is a normal gene that could become an oncogene due to mutations. This process has mechanisms to ensure that errors are corrected, if they are not, the cells commit suicide (apoptosis). This process is tightly regulated by the genes within a cell’s nucleus. In cancer, as a result of genetic mutations, this process malfunctions, resulting in uncontrolled cell proliferation. Mutations in proto-oncogene or in a tumour suppressor gene allow a cancerous cell to grow and divide without the normal control imposed by the cell cycle. A change in the DNA sequence of the proto-oncogene gives rise to an oncogene, which
The nucleus of a cell keeps the cell going as a result of its the mainframe of a cell therefore it controls what happens inside a cell,what the cell will do and the way the cell is going to be used. Found inside of the nucleoplasm, the nucleolus is a consolidated district of chromatin where ribosome manufacturing happens.
The mitochondria is an organelle which is generally an oval shape and is found inside the cytoplasm and is again apart of the eukaryotic cells. The main function of the mitochondria is to complete cellular respiration; in simple terms it acts like a digestive system to break down essential nutrients and to convert it into energy. This energy is usually found to in ATP which is a rich molecule taken from the energy stored in food. Furthermore, mitochondria stores calcium for signalling activities; such as heat, growth and death. They have two unique membranes and mitochondria isn’t found in human cells like the red blood cells yet liver and muscle cells are filled entirely with mitochondria.
Cells are able to grow and reproduce. Cells reproduce by splitting and passing on their genes (hereditary information) to Daughter cells. The nucleus always divides before the rest of the cell divides. Therefore each daughter cell contains their own nucleus. The nucleus controls the cells activities through the genetic material DNA. The cells in a body are all the same except the gametes they were all made from one cell, the Zygote. This is the cell that was formed when two gametes from your parents fused.
The cytoskeleton is a highly dynamic intracellular platform constituted by a three-dimensional network of proteins responsible for key cellular roles as structure and shape, cell growth and development, and offering to the cell with "motility" that being the ability of the entire cell to move and for material to be moved within the cell in a regulated fashion (vesicle trafficking)’, (intechopen 2017). The cytoskeleton is made of microtubules, filaments, and fibres - they give the cytoplasm physical support. Michael Kent, (2000) describes the cytoskeleton as the ‘internal framework’, this is because it shapes the cell and provides support to cellular extensions – such as microvilli. In some cells it is used in intracellular transport. Since the shape of the cell is constantly changing, the microtubules will also change, they will readjust and reassemble to fit the needs of the cell.
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. But it also contains highly organized physical structures which are called intracellular organelles. These organelles are important for cellular function. For instance Mitochondria is the one of most important organelle of the cell. Without Mitochondria more than 95% of the cell’s energy, which release from nutrients would cease immediately [Guyton et al. 2007].
The Animal Cell is a little bit different than the Plant Cell for only a couple of reasons. One is how the Plant Cell has a cell wall and the Animal Cell doesn’t. The cell wall protects and gives structure to the cell. Then there is the Nucleus, which serves as a control center for the cell. Inside the Nucleus there are one or more Nucleoli. They are dense, granular bodies that disappear at the beginning of cell division and reappear at the end. Then you have the Cytoplasm. This is the watery material lying within the cell between the cell membrane and the nucleus. The Cytoplasm also contains organelles, which have specific functions in the cell metabolism. Then there are the Golgi Bodies, which serve as processing, packaging, and storage for the cell. These organelles package and ship things out. Another parts of the cell, a very important one in fact, are the Lysosomes. These organelles are used to break things down and contain enzymes.
Cell biology is the study of cells and how they function, from the subcellular processes which keep them functioning, to the Their main purpose is to survive and their functions allow them to do so. All cells have common features whether they are eukaryotic or prokaryotic cells. The common features include a plasma membrane, cytoplasm, ribosomes, and DNA. A plasma membrane which is also known as a cellular membrane, surrounds all cells and its primary function is to protect them.
What is the cell cycle? It’s the way we reproduce. A series of events lead up from the beginning that which gives them life to the splitting of cells, The separate steps make up this very important process. Without the division of cells, we simply would not be here today.