Cloning and Genetic Engineering, by YY

          It is quite astounding to think about how everything began, or why it is the way that it is. Each and everyone one of us began our journey as one single embryo created by our parents. From those few cells, we begin to grow and mature into a whole different individual, and eventually become sustainable on our own.

          The countless processes which we undergo as we transfer from that one cell to an entire being composed of billions of cells are through a very important process called mitosis. Mitosis is a process named and discovered by Walther Flemming in the 1800s, which allows cells to divide into two identical cells. It is a fact that nothing can live forever, and the same applies to cells. As a cell becomes larger, soon its surface area to volume ratio decreases too fast for the cell to absorb nutrients thoroughly, and so it is left with the option to die or to divide.

          During mitosis, the cell undergoes 6 main phases; interphase, prophase, prometaphase, metaphase, anaphase, and telophase. Interphase is the regular activity of the cell, and when organelles are replicated. In prophase, the chromosomes condense, and each chromosome is made up of two sister chromatids. Prometaphase is when the nuclear envelope breaks down completely and the spindle fibres having attached to the centromeres and the centrosomes have reached the poles of the cell. When the chromosomes have all aligned at the center of the cell, it is then at the metaphase stage. During anaphase the spindle fibres pull the chromosomes to opposite ends of the cell. Finally, in telophase the membrane begins to pinch in and the actin filaments separate the cytoplasm. Each minute, cells are constantly undergoing mitosis, and dividing into two new diploid cells.

          Yet as we speak, scientists are constantly working on new forms of technology of improving and introduce new ideas into our lives. Centuries ago, it would have been crazy to think that other ways of life can be produced other than by sexual reproduction, but now as we look at our technology, it is understood that there is a vast, unexplored side to science that will always drive the curiosity of humans. In recent years, new ideas such as cloning, DNA alterations, and other genetic engineering methods have been introduced and explained to the public.

          In 1996, scientists finally succeeded in understanding artificial cloning, and Dr. Ian Wilmut successfully cloned the first ever mammal, a sheep named Dolly. Cloning is a complicated process, but in the end produces an exact replica of the original organism cloned. Dolly was the product of 3 parents, and is genetically identical to the DNA donor, an adult Finn Dorsett ewe. Cloning involves a somatic cell donated from one sheep, with the nucleus removed. Nucleus from another sheep is then inserted into the egg cell and fused together, and fertilized. Finally as the egg cell divides into an embryo, it is then inserted into a third sheep, where the normal birthing process takes place. The newborn lamb Dolly is genetically identical to the adult Finn Dorsett ewe of the nucleus donor, which would not have been dreamed of being possible decades ago. Even Dr. Ian Wilmut himself had doubts of the experiment, and was amazed to see that the experiment had succeeded.

          By discovering cloning, we have taken a huge leap forward in technology and to improving our lives. It also opens a wide doorway to immense possibilities to what human beings can achieve. But along with new discoveries, there will always be debated issues on the morality of doing so. People argue whether or not it is right to “play God” in situations like these where genetic structures are altered and life is created through a complicated and unnatural process in petri dishes. But whether or not these new technologies are allowing us to improve our lives, or if it is ethically wrong to create altered organisms, is another story for another time.

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Modern Classification of Blood Types, by SY

     Ever since the start of evolution and maturation of what is known as mankind and Homo sapiens today, scientists have been interested in the different compartments that make up the human body, allowing it to function phenomenally with the ability to perform various tasks and types of chemical reactions, reproductive hormones and the different array of diseases and virus control within the different systems. An interesting factor of the human body is contained within the genetic information and DNA models of each individual, no individual on the planet is alike, even the tiniest differences could tell people apart based on the inheritance traits derived from combinations of chromosomes that carry single long molecules of DNA and associated protein in prokaryotic cells and multiple linear chromosomes located in the nucleus. Based on these unique structures present in the human body, a fascinating point reveals itself known as the different blood types.

     Bloody types were not discovered until 1901; biologists had difficulties understanding why only a percentage of transfusions worked and others did not. The different reactions from patients displayed to scientists that there are indeed, human blood is not identical, and certainly does not contain similar characteristics from person to person. Karl Landsteiner from Vienna, Austria made an astonishing discovery in 1901 that human blood differs from one another with four main blood groups; he also distinguished a distinct system used for classification of the different blood groups based on his observations regarding the presence of agglutinins in the blood. Alongside with Alexander S. Wiener, the discovery of the Rhesus factor in 1937, enabled physicians and doctors to transfuse blood successfully without endangering the patient’s life. Since the discovery of the four main blood type groups, over 300 more have been identified throughout history, these sections are correlated to one specific main component of the four major types.

     The Classification of blood groups is identified by the existence or deficiency of inherited antigenic substances on the surface of red blood cells, or in some rare cases, available on the surface of other cells or on various types of tissues. These antigens maybe acknowledged as carbohydrates, glycoproteins, proteins, or glycolipids. The majority of red blood cell surface antigens from allele or closely linked genes will ultimately form a blood group system. About 30 human blood systems are recognized by the ISBT (International Society of Blood Transfusion). Before complex DNA testing and blood test, blood types were a quick and efficient way to determine paternity from the result of reproducing offspring. The reason for this mechanism is because the main blood types of a child are directly linked to the blood types of their parents. The determination of blood type is not a complex process as there are only four major blood type categories to choose from. A, B, AB, and O. Each parents has two of these ‘characters’ in their blood type and passes it on similar to DNA transport of genetics. At this point, anyone may be wondering how the classification of blood types into determining the blood type of the child works; for example, if a father possessed type AA blood and the mother possessed type BB blood, the only possibility of the blood type of the child is AB. If both the mother and father possessed OO blood, the child’s blood type could only be OO. Another case scenario that is common in many individuals is if the mother contained type AA blood, and the father contained AB, the chances of the child being AA or AB is half and half. This system is known as the ABO blood group system which is the most important and significant blood-group system in human blood-transfusion today.

     The patterns and details in the human body determine the variation and uniqueness within each individual. The complexity of this topic is reflected based upon the distinctive traits and characteristics that make up individual, blood type may not seem significant in a person’s comparative source of difference from another individual, but it is the genesis of human life as DNA genetics and genotyping are major components of this subject.

 

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Monkey Business, by SX

         I like monkeys a lot. However, even with my adoration for monkeys, I had my doubts when I learned that Japanese scientist had managed to breed glow-in-the-dark monkeys. I mean, first of all, why anyone would want to make glowing monkeys baffles me and animal rights activists probably won’t be very happy. But seeing that they’ve already got things like magic slipper cleaning machines, and shoe washing machines, glow-in-the-dark monkeys don’t actually seem like that big of a deal. After my initial shock, I’ve come to appreciate both the attractiveness of these monkeys and their other scientific benefits.

          First off, it’d be nice to know how they were bred right? Well, Japanese scientists at the Central Institute for Experimental Animals in Kawasaki, Japan, injected a gene found only in jelly fish into marmoset embryos that produced a chemical called green fluorescent protein (GFP). GFP was used because the gene is an easy one to track as cells that have the gene glow green under fluorescent lighting. Now, the glowing monkeys that grew from the embryo aren’t really that big of a deal because glowing animals have been created before, but what is a big deals are the baby monkeys that the original monkeys gave birth to. The baby monkeys’ feet glowed when exposed to fluorescent lights, meaning that the gene was passed down from the mother. This is significant because this is the first time in history that the gene has been passed down successfully from the mother to the offspring.

          Because the scientists have successfully passed down green fluorescent protein (GFP) in monkeys, they are now able to recreate human type neurodegenerative diseases in monkeys. Scientists plan to create families of monkeys that develop neurodegenerative diseases found in humans so they can study human diseases and progress toward cures for human health genetic disorders. Researchers say that these monkeys are a step toward cures for human health genetic disorders like Parkinson’s and motor neurone disease. Scientists will also study the monkeys to find why certain genes cause diseases in some babies but not others. The Japanese scientist, Erika Sasaki and her team who breed these monkeys states that: “Our method promises to be a powerful tool for studying the mechanisms of human diseases and developing new therapies.” Now, although transgenic mice have also been used to observe human diseases, they are too different from human beings to accurately model many human diseases. Using primates will be more informative to scientists and will give them a better chance to study how diseases affect humans because they are similar to primates.

         Although this a huge step towards finding cures for human diseases, there are still many people that oppose the use of monkeys as test subjects. Animal rights groups say that the transgenic monkey research by the Japanese team may result in many other families of primates that will be forced to suffer an overabundance of cruel illnesses and risky medical experiments.

          Also, due to human beings having a close genetic relationship with primates like marmosets, some animal rights groups have voiced their concern that the glow in the dark transgenic techniques could even be used on humans. Dr Gerald Schatten of Pittsburgh University warns, “Although the future for using transgenic primates for research looks bright, scientists need to engage with the public in inf­ormed bioethical debate.” and added that there are many ethical concerns with colonizing families of monkeys with human diseases. While Vicky Robinson, who campaigns to reduce use of animals, also said: “We can’t assume a transgenic marmoset will be better for disease research than, for example, a transgenic mouse. Any researcher will need to show the added scientific value of using a monkey outweighs the significant ethical considerations accompanying its use.”

          Although there are many pros and cons, I think it’s amazing how an experiment with glow-in-the-dark monkeys could possibly lead to the discovery of cures for diseases like Parkinson’s disease. And while these green monkeys are certainly nice to look at, this experiment also holds a higher significance as the method can also be used to pass on neurodegenerative diseases in monkeys, which gives scientists a chance to study these diseases in animals that are closely related us.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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The Cell Theory: Unity of Life, by NW

          The Cell Theory is among many unique aspects of biological science. In fact, it is the basic building block of the evolution of the study of biology. The vast amount of knowledge we contain of biodiversity is in part due to the contributions of the cell theory. It consists of the foundation for the development of ideas and theories which altered the way scientists understood life on Earth.

          First of all, what is a theory? It is a justification for a general class of observations or discoveries. The cell theory was found and established by three scientists over the course of the mid 1800’s. Their discoveries led to the improvement of the cell and opened a whole new world of discovery.

 The Cell Theory states:

 1.  All life functions take place inside of cells, making them the basic unit of life.

2.  All organisms are made up of cells.

3.  All cells originate from pre-existing cells.

          The earliest recorded discovery in the history of cells is in 1665, when the concept of cells first emerged. Robert Hooke, an English natural philosopher, used a light microscope to examine thin slices of plant tissue: cork. He carefully observed the specimen and saw that it contained a massive amount of tiny pores which he noticed looked very similar to compartments monks would live in.. He therefore called these tiny chambers “cells”. However, Hooke’s observations on cells specified there were no organelles or nucleus present, so the samplings he studied were not living.

          The first scientist to survey living cells was Anton van Leeuwenhoek, who in 1678 observed algae Spirogyra and obsereved that they were like “little animals”. Based on his discoveries and findings, he drew the conlcusion: “All life functions take place inside of cells, making them the smallest unit of life.” This is the first component of the Cell Theory.

         In 1838, Matthias Schleiden, a German botanist, began studying and examining different kinds and species of plants to identify any details on the characteristics of cells or any restrictions in the organisms in which cells existed. He observed and noticed that all plants and specimen he examined consisted of cells, and came to the conclusion: “All plants are made of cells.” His friend and lab research partner Theodore Schwann was a German scientist, a zoologist, who studied the structure and composure of animals. Through the influence from his friend, Schwann was inspired to conduct the observations Schleiden made about plants and convert it to animals. In 1939, after much examination, he stated that since all of the animals from the variety he chose contained cells, “All animals are made of cells.” Having reached a satisfying finale throughout well-conducted experiments and through observations, Matthias Schleiden and Theodore Schwann claimed: “All living things are made up of cells, completing the second element of the Cell Theory.

         The final stage of the Cell theory was accomplished by a German physician named Rudolf Virchow. He is widely-known for his involvement in the founding of the Cell Theory, who built on the work of Theodore Schwann. Virchow studied medicine and chemistry inBerlinand became interested in discovering more about the existence and creation of cells. He is recorded in history as the first person to examine and recognize leukemia cells. Although at first he did not accept the past discoveries of cell division, and believing that it only occurred in certain types of cells, he later began to do more research and conduct his own experiments on a variety of specimen. This declined the concept of spontaneous generation. which stated that organisms could arise from non-living matter. It was believed, for example, that maggots could spontaneously appear in decaying meat however Louis Pasteur carried out experiments which disproved this. Virchow concluded that according to his observations that it was only possible “for cells to arise only from pre-exsisting cells.”

            The Cell Theory has affected the perspective scientists and biologists look at the world and understand its concepts. The first component of the theorym states, “All life functions take place in the cell, making it the smallest unit of life.” To elaborate in this contention, I will connect specific examples to this idea. First, the human body contains cells, organs, muscles, and systems which opereate to perform various functions that assist the body in some way. Likewise, a cell is like a human body, except a magnitude smaller in size, yet the similarities are quite clear. The cell has organelles and various operations which function for a variety of purposes that assists the cell in survival. The second compartment of the cell theory, claims “All living things are made up of cells”, which recent reseach and discoveries have proven to be true. From micromolecules to the giant whales in the ocean, all living organisms consist of cells because they are the essential ingredient for survival and perhaph adaptation. Although it may range, from a bacteria containing one cell to the billion cells contained by an animal, the theory applies with no restrictions.

         Moving on to the third stage of the Cell Theory: “All living cells arise from pre-existing cells”. Cellular division is one of the most important components of biology. It is the reason that the human population is what it is today, and why Earth contains a vast amount of diversity with its life systems. Although there are many forms of cellular division, all go through the process for one main purpose: the replication of DNA which eventually leads to reproduction and new life forms. Mitosis and Meiosis are two methods of cell division, that are used by unicellular and multicellular oragnisms. Each contain its own advatages and disadvantages, howver biodiversity is hugely part of both.

          Wrapping up, the cell theory has been the foundation of a basis of experimentation and discovery of one of the most essential elements of science. the Cell Theory led to the development and improvement of microscopes which further changed the view of cells for scientists. These are all events which have occurred in the past that have affected us in the present more than we could know, and there’s no saying where we would be if it weren’t for these discoveries and theories.

 References

 Freeman, S. 2008 Biological Science, Tenth Edition

 

 

 

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The Vital Organelle, by NV

          Many scientists around the world focus on obvious cell organelles such as nuclei and cell membranes, and they do not notice other vital organelles that are necessary for the survival of living things. An organelle in plant cells that carries out an astonishing process is called a chloroplast. A chloroplast is defined as a chlorophyll- containing organelle, bounded by a double membrane, in which photosynthesis occurs. It is essentially the food producer of plant cells. It is found in plants and protists, and it is the location of amino acids, fatty acids, purine, and pyrimidine synthesis. Chloroplasts also carry out photosynthesis, which is defined as the complex biological process that converts the energy of light into chemical energy stored in glucose and other organic molecules. Chloroplasts derive from proplastids. As cells mature, proplastids develop into chloroplasts or other types of plastids specialized for the cell’s task. Chloroplasts also grow and divide independently of nuclear division and cell division. This blog entry describes the history of chloroplasts, its structure, and its various functions.

            The combined knowledge and experiments of many scientists resulted in the discovery of the chloroplast and its various components. Chloroplasts were first described in the 7th century by Nehemiah Grew and Antony van Leeuweenhoek. But, in 1837, Henri Dutrochet observed that chlorophyll was essential for the development of oxygen in plants. After this observation, Meyer described the structure of the chloroplast in 1883. He pointed out the thykaloid disks, double- membranes, granum, lumen, lamellae, and stroma, which will be described later on in this blog entry. Also, in 1883, Schimper stated that chloroplasts belong to the group of plastids, and he also stated that chloroplasts closely resemble cyanobacteria (a photosynthetic prokaryotic organism containing a blue pigment in addition to chlorophyll). Mereschkowsky stated in 1905 that cells synthesize sugar from just water, carbon dioxide, and sunlight. In 1909, the idea that genetic factors existed in chloroplasts was proposed. Half a century later, the existence of DNA in chloroplasts was confirmed. When electron microscopy became available in the 1950s, researchers and scientists observed that chloroplasts are extremely membrane rich. When membranes derived from chloroplasts were found to release oxygen after exposure to sunlight, scientists concluded that chloroplasts are the site of photosynthesis. Experiments with plant tissues established that photosynthesis only takes place in the green parts of plants, and other work with light microscopes showed that these reactions take place inside chloroplasts.   

            Although chloroplasts are only present in plant and algae cells, they play an essential role in the survival of the cell. The basic function of the chloroplast is to use chlorophyll for the production of sugars and starches in the cell. Plants then use the sugars (glucose) for food and energy. When sunlight hits a chloroplast, the chlorophyll uses the light energy and carbon dioxide to form sugar and oxygen. This process is commonly known as photosynthesis. Plants use the sugars that are produced for their own survival and they release oxygen for our survival. In conclusion, the main function of chloroplasts in plant cells is to produce ATP (adenine triphosphate, a molecule consisting of adenine, a sugar, and three phosphate groups that can be hydrolyzed to release energy) via photosynthesis.

            The number of chloroplasts per cell varies from none to several dozen. Typically, leaf cells contain 40-50 chloroplasts. A square millimetre of leaf has around 500,000 chloroplasts!

            The structure of the chloroplast is highly- structured and membrane bound. Chloroplasts contain pigments and enzymes that catalyze oxidization- reduction reactions and drive ATP synthesis. Two membranes contain and protect the inner parts of the chloroplasts. The stroma of the chloroplast is an area inside the chloroplast where reactions occur and where starches are created. Certain critical enzymes and substrates are found outside the thykaloids in the stroma. Chloroplasts also contain thykaloid disks, which are flattened- membrane bound vesicles that convert light energy into chemical energy. This occurs because thykaloid disks have chlorophyll molecules on their surface, which results in the usage of sunlight to create sugars and energy. Many of the pigments, enzymes, and molecular machines responsible for converting light energy into carbohydrates are embedded in the thykaloid membranes. The space inside a thykaloid disk is called lumen, which is a general term for the interior of any sac- like structure. A stack of thykaloids is called a granum. Granum are connected by stromal lamellae, which functions to keep all of the sacs a safe distance from each other and increase the efficiency of the organelle. Chloroplasts also contain chloroplast DNA, which is independent of the main genetic material inside the nucleus. This DNA codes for redox proteins involved in electron transport in photosynthesis.

            Why are plants green? When researchers analyzed the chemical composition of thykaloid membranes, they found that these membranes had large quantities of pigments. A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. Pigments have colours because we see the wavelengths that pass through or bounce off of them. The most abundant pigment found in the thykaloid membrane is chlorophyll, which absorbs light during photosynthesis. This pigment reflects or transmits green light, and as a result, it is responsible for the green colour of plants. From this, we can conclude that chloroplasts are the reason behind plants being the colour green.

            Chloroplasts often go unnoticed, but it cannot be disregarded that they play a vital role in plant cells. They are responsible for the energy and food production of the cell. Through photosynthesis, light energy is converted into a form of chemical energy called ATP, which provides energy to the cell. It is a highly-structured organelle, since it contains thykaloid disks, granum, inner and outer membranes, stroma, stromal lamellae, and lumen. In conclusion, chloroplasts are significant organelles in plant cells that carry out an astonishing process and aid in the survival of the human race.

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Cancer, by JZ

          Cancer is a word that almost everyone on the world would know.  However they probably don’t understand what cancer is except it’s an illness.  Cancer is when cells divide excessively, invade other tissues and don’t respond to the body’s control mechanisms.  Cancerous cells also don’t have a dividing limit.  When normal cells might divide 50 times; cancerous cells can keep on dividing indefinitely if there is a constant supply of nutrients.  The excessive division will lead to the development of a malignant Tumour or a benign Tumour.  If the abnormal cells stay where it is originally then the Tumour is considered benign.  Most benign Tumours do not cause any serious problems and can be completely removed by surgery.  A malignant Tumour is the opposite; it spreads and impairs the function of organs.

          The cells of a malignant Tumour are abnormal in several ways first is their excessive proliferation.  They may also have an unusual number of chromosomes and the cells may cease to function in any constructive way.  When these cancerous cells enter blood vessels and lymph vessels, they can travel to other parts of the body and form new Tumours.  This movement process is called metastasis.

            People who are at the most risk from cancer are usually smokers and alcoholics.  Cancer gives most people no symptoms that exclusively indicate the disease.  Most of the cancer symptoms can also be symptoms for common illness.  Some of the common symptoms for cancer include fatigue, cough, and weight loss.  Fatigue is the most common symptom for cancer because the body’s immune system has to destroy the cancerous cells.  The battle to destroy malignant cells is an on-going battle for month or even years.  Coughing is a symptom from many illnesses.  In terms cancer, coughing with blood or mucus is a symptom for lung cancer.  Weight loss can also be a symptom of different types of cancer.  Cancerous cells live off of our nutrients and release wastes inside our body.  This will cause your body to lose a slight bit of nutrients, which will eventually lead to a more significant decrease in weight.

            So what causes cancer?  Cancer like most other illnesses requires a couple of factors to cause it.  Some of the causes are sunlight, smoking and age.  Cancer happens when some of the genes in a cell are changed.  This change may result from an accident during division, or can be long term mistakes that our cells make.  The older people get the more potential mistakes a cell can make.  The genetic damage can also be done by the environment.  This would be smoking, sunlight and radiation, these things have a potential to cause genetic mutations.  Aside from changes to the genes, people can be born with the mutations.  Although this doesn’t necessarily mean those people will have cancer, but the risk definitely increases.  Overall the best way to prevent cancer is to maintain a healthy body weight, healthy diet and regular physical activities.

            A couple of ways to treat cancer is surgery, radiation and chemotherapy.  Surgery is the physical way of removing a Tumour, surgery is also useful in analysing the Tumour.  Samples of the Tumour can be taken through surgery and viewing the cells under a microscope can further identify the nature of the cancer.  Surgery is also often used with other forms of treatment.  It is believed by removing a majority of the cancer will make other treatments more effective.  Radiation treatment is using higher-energy radiation to damage the cancer cells’ DNA.  This is effective because cancerous cells have lost the ability to repair such damages.  Chemotherapy is used when the type of cancer is known or suspected metastatic Tumours.  Chemotherapy uses drugs to interfere with the specific steps in the cell cycle.  This form of treatment will have side effects on normal cells; some examples include nausea, hair loss and infections. 

 

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Endomembrane Transport System, by GZ

            The endomembrane system is responsible for shipping different proteins into certain compartments of a cell. Lysosomes need to receive enzymes whereas the nucleolus may need additional ribosomal proteins. Since proteins are more sophisticated than ions and small molecules that diffuse throughout the cell, they need to be specially apportioned. The proteins assembled by chains of amino acids in the ribosome must be able to displace from their location on the rough endoplasmic reticulum to the extracellular matrix, nucleolus, lysosome, peroxisome and other organelles that require proteins. In essence, protein transport, whether of enzymes, catalase or hormones, is aided by other motor proteins. Organelles that are part of the endomembrane system include the rough endoplasmic reticulum which is continuous with the nuclear envelope, the Golgi apparatus and the cell membrane. Transport vesicles are the organelles that connect the whole system. Transport can happen within the cell or can occur from the cell to the extracellular environment.
            Proteins like hormones that carry special signals may use the endomembrane system to exit its immediate cell to reach other cells in the organism. In order for proteins to be expelled, the proteins produced in ribosomes bud off the rough endoplasmic reticulum into transport vesicles that have a unit membrane. After, the proteins are directed to the cis face of the Golgi apparatus where lumen of the Golgi apparatus catalyzes the protein for it to become a glycoprotein. The Golgi apparatus is composed of flattened stacks of cisternae; the number of stacks correlates to how active the cell is in secreting proteins.  From the trans face of the Golgi apparatus, the transport vesicle is dispatched. Another type of protein, a motor kinesin protein must now attach to the transport vesicle.  ATP which phosphorylates to ADP in order to release the chemical potential energy attaches to the kinesin protein that moves the glycoprotein along microtubules tracks. These microtubule tracks lay the pathway towards the cell membrane. When the transport vesicle finally reaches the cell membrane, the vesicle’s membrane fuses with the cell membrane. Microtubules are responsible for holding the membrane open for expulsion. Exocytosis occurs for the protein to exit the cell. The high concentration of the protein will diffuse to the extracellular matrix to minimize the concentration gradient and reach other cells in different region of the multi-cellular organism, to where they were destined for.
            Other modes of transport of the endomembrane system happen intracellularly. Perhaps a mitochondrion has become damaged. It must be directed to the lysosome to be digested. This process is part of the endomembrane system in that enzymes and membranes of the lysosome are synthesized in the rough endoplasmic reticulum and processed through the Golgi apparatus. Once again vesicles containing the damaged organelles will be directed to lysosomes. A lysosome will fuse with the vesicle and digest the matter. Through lysosomes, cells can renew themselves.
            The endomembrane system is an extensive system responsible for the movement of proteins and other sophisticated molecules since the simple diffusion of them will not work. They must be specially directed. This system assists in regulating protein traffic. Proteins play many roles in organisms from acting as signals (hormones), helping to quicken reactions (enzymes) and are involved in structural roles (actin filaments of a cell). However, this is another story for next time.

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