Medical biology
Introduction
General medical biology is one of the required courses that are related to the department course. I have learned a variety of lessons from this course, such as cell structures and its functions, different types of cells, and how cells can divide—studying microorganisms such as bacteria, parasites, and viruses. The combinations of all lectures helped me understand the life and structures of living and non-living organisms, all the information related to the human body. We studied several lectures by the E-Learning mechanism due to the global pandemic. Generally, the subject was delivered correctly. Besides general medical biology class, we had a general medical biology lab. In the Lab, we introduced to the microscope and its types, observing different human tissues under a microscope, learning what will happen to blood in three different solutions: Hypertonic, Isotonic, and Hypotonic solutions. DNA isolation and PCR technique. Furthermore, these lectures will influence my future job, Pharmacist, because I understood how the body works, and in the next years, I will know how to treat the disorders with medicines.
- What are the environmental factors that affect the growth of bacteria? Enumerate and describe only two of them.
Answer/ Bacteria is one of the types of microorganisms. Some environmental causes can affect bacteria’s growth, for example, Temperature, Oxygen, Osmosis, and pH. Temperature: Bacteria have the lowest, optimum, and highest temperatures for growth and can be divided into three groups based on their optimum growth temperature: for instance, psychrophiles are cold-loving bacteria. Their optimum growth temperature is between -5C and 15C. They usually could be found in the Arctic and Antarctic regions and streams fed by glaciers. Mesophiles are bacteria that grow best at average temperatures. Their optimum growth temperature is between 25C-45C. Most types of bacteria are mesophilic and include common soil bacteria and bacteria that live in the body. Thermophiles are heat-loving bacteria. Their optimum growth temperature is between 45C and 70C and is commonly found in hot springs and in compost heaps. Hyperthermophiles are bacteria that grow at remarkably high temperatures. Their optimum growth temperature is between 70C and 110C. They are usually members of the Archaea and can be found growing near hydrothermal vents at great depths in the sea. Another factor is oxygen requirement. According to the different amounts of oxygen that bacteria want to grow, they can be placed under the following groups: Obligate aerobes are organisms that grow only in the presence of oxygen. They get their energy through aerobic inhalation. Microaerophiles are organisms that need a low intensity of oxygen (2% – 10%) for growth, but higher concentrations are inhibitory. They get their energy through aerobic inhalation. Obligate anaerobes are organisms that only grow in the lack of O2. Indeed, they are often inhibited or killed by their presence. They get their energy through anaerobic inhalation or fermentation. Aerotolerant anaerobes, like obligate anaerobes, cannot consume oxygen to transform energy but can grow in its presence. They get energy only by fermentation and are recognized as obligate fermenters. Facultative anaerobes are organisms that grow with or without oxygen, but generally better with oxygen. They get their energy through aerobic respiration if oxygen is present but use fermentation or anaerobic respiration if it is missing.
- What are the main differences between meiosis and mitosis?
Answer/ Cells divide by two different mechanisms, which are meiosis and mitosis. Here are some significant differences between meiosis & mitosis: In mitosis, the cell involves one division. The result is two daughter cells, while in the meiosis involves two successive cell divisions, and the result is four daughter cells. The chromosome number remains the same as parent cell in mitosis, but in meiosis, the chromosome number is halved from the parent. In mitosis, the daughter cells are identical, but in meiosis, the daughter cells are generally different. Mitosis division occurs in all organisms except viruses, and it created all body cells apart from germ cells (egg and sperm). However, meiosis division occurs only in animals, plants, and fungi and creates germ cells only.
- What is the reverse transcriptase enzyme? Moreover, why do retroviruses need reverse transcriptase?
Answer/ Reverse transcriptase, also known as RNA-directed DNA polymerase, an enzyme encoded from the genetic material of retroviruses that catalyzes the transcription retrovirus RNA into DNA. This catalyzed transcription is the reverse process of normal cellular transcription of DNA into RNA, therefore the names polymerase and retrovirus, the polymerase is central to the infectious nature of retroviruses, some of which cause disease in humans, including human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS), and human T-cells lymphotropic virus I (HTLV-I), which causes leukemia. A polymerase is also a critical component of a laboratory technique known as reverse, transcription-polymerase chain reaction (RT-PCR), a strong tool applied in research and within the diagnosis of diseases.
- Briefly describe the types of cell transport.
The answer/ Cell transport mechanism allows the molecules to pass through and out of the cell membrane. We have two different types of cell transport: Active transport and passive transport, Active transport needs energy as (ATP) form to transport molecules from the low-concentration area to the high-concentration area. Also, active transport has three different types which are: primary active transport moves the sodium and potassium ions through the plasma membrane, secondary active transport, and vesicular transport move macromolecules or large particles across the plasma membrane. There are two types of vesicle transport, endocytosis, and exocytosis. Passive transport does not need the energy to transport molecules from the high-concentration area to low-concentration areas. There are three forms of passive transport: Simple diffusion, which is for movement of small molecules like Oxygen and Carbon dioxide through cell membranes. Osmosis, which is for the movement of water, it depends on solute concentration. The last one is Facilitated diffusion, which is for movement of large or charged molecules passing through membrane proteins like ions, sucrose.
- Why does Fasciola hepatica produce cyst?
Answer/ Most of the parasites produce cyst to protect themselves from any dangerous condition. Dangerous substances, to increase their numbers, and to live without having water, food, and target cell for a long period of time.
- Why does Giardia lamblia cause diarrhea?
Answer/ Giardia lamblia is a parasite that causes diarrhea is human. It has two forms: Cyst and trophozoite, when you drink contaminated water or food with this parasite, it goes into your stomach, and stomach acid HCl activates the cyst, then the trophozoites go into your small intestine and attach to the linear mucosa surface of the small intestine and block the small intestine to absorb fat and carbohydrates from digested food.
References:
1) Burton J.Bogitish, Clint E.Carter, Thomas N.Oeltmann. (2013). Human Parasitology (4 th ed.,
pp.73-77). Academic Press.
2) Elizabeth R.C.Cregan. (2008). All About mitosis and meiosis. Huntington Beach, CA: Teacher
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3) Skowron, G.Ogden, R. (2007). Reverse Transcriptase Inhibitors in HIV/AIDS Therapy (pp.1-26).
Springer Science & Business Media.