Microbiology
1. Are viruses alive or not alive?
This is a type of question that can be argued either way. Some may say that viruses are definitely alive while others say that are not alive. So which one is right? Overall, viruses are not living for many reasons. For example, all life is made up of a cell or many cells. However, viruses are not made up of cells, instead they consist of a nucleic acid molecule in a protein coat. All life also responds to its environment and which viruses do not. Viruses don't care about their surroundings. The only thing that they do is attach themselves to host cells, infect them and multiple themselves. This is another reason why viruses are not living. Another strong example is viruses do not eat which also implies that their biomass also does not increase. These are two more characteristics in which viruses do not contain. You can argue that they are alive because they contain DNA/RNA which is the basis of all life but there is too much evidence to support that they aren't alive.
2. Why someone is never cured of herpes
To start off the explanation for why someone is never cured of herpes first I will explain the 2 virus cycles: lytic cycle and lysogenic cycle.
Lytic cycle:
In basic terms the lytic cycle is when a virus enters a cell, replicates itself, then bursts the cell causing multiple viruses to leave and find new cells to attack. The lytic cycle is also known as the impatient cycle because unlike the lysogenic cycle, the virus tries to infect as many cells as quickly as possible. This cycle can be put into 5 main steps as shown below.
1. Attachment- In this step the virus attaches itself to the host cell.
2. Entry- In this step the virus injects its DNA/RNA into the cell forming a circle (doesn't join cells genome)
3. Replication- In this step the cell starts replicating mRNA because they cannot tell the difference between the viral DNA and their own DNA. The mRNA then gets translated into viral proteins where start creating more viruses.
4. Assembly- In this step the viruses have finished replicating and are ready to infect new cells.
5. Lysis- In this step the virus breaks the cell wall with a special enzyme and infects a new cell starting the cycle over again.
1. Attachment- In this step the virus attaches itself to the host cell.
2. Entry- In this step the virus injects its DNA/RNA into the cell forming a circle (doesn't join cells genome)
3. Replication- In this step the cell starts replicating mRNA because they cannot tell the difference between the viral DNA and their own DNA. The mRNA then gets translated into viral proteins where start creating more viruses.
4. Assembly- In this step the viruses have finished replicating and are ready to infect new cells.
5. Lysis- In this step the virus breaks the cell wall with a special enzyme and infects a new cell starting the cycle over again.
Lysogenic cycle:
In basic terms the lysogenic cycle is when a virus integrates its DNA into a host cell, the cell replicates along with the viral DNA, causing each newly replicated cell to contain the viral DNA. This cycle is know to be more "lay back " or "hitch a ride" type of cycle because although every replicated contains some viral DNA, that viral DNA remains dormant until an event occurs causing the viral DNA to separate from the host's thus beginning the lytic cycle. The Lysogenic can be shown in the steps below.
1-2. The first 2 steps are the same as in the lytic cycle where the virus attaches itself to a host cell and injects its DNA/RNA
3. Integration- In this step the viral DNA integrates into the hosts DNA (Prophage)
4. Cell Multiplication- In this step cell division takes place in which each new cell contains host and viral DNA. After however much time, the viral DNA will separate from the host's and will begin the lytic cycle.
1-2. The first 2 steps are the same as in the lytic cycle where the virus attaches itself to a host cell and injects its DNA/RNA
3. Integration- In this step the viral DNA integrates into the hosts DNA (Prophage)
4. Cell Multiplication- In this step cell division takes place in which each new cell contains host and viral DNA. After however much time, the viral DNA will separate from the host's and will begin the lytic cycle.
Answer:
When someone first gets herpes, the virus gets into your body and infects a cell. As this virus infects your cell it begins to replicate itself causing more viruses to attack more cells. Although you may think this may repeat forever, the virus will die off. For example, for 1 week you have a cold sore but after that week it disappears. From this point on even though the herpes seems to be gone, it is actually still in your body. In fact, it's in your cells at any given moment in it is just in the form of DNA through the lysogenic cycle. Then once the virus feels like it is ready to attack again, it separates its DNA from the host's and starts infecting more cells which is the lytic cycle. At that moment you may get another cold sore like the one before that you thought was gone forever. Overall, once infected you are never cured from herpes because it is embedded in some of you cells DNA and is only used at various moments. Yes, it seems like it eventually goes away but it is just dormant, waiting to infect again!
3. 3 ways the body can defend against micro-organisms
Phagocytosis- This is the process in which the host's white blood cells eat the pathogens that have infected cells. Once the infection is detected, the white blood cells, mostly phagocytes enter the infected area and eat the pathogens. Once they engulf the pathogen it is then destroyed by using enzymes in their lysosomes. However, some virus particles are blended in well making it hard for the phagocytes the detect and destroy them.
Interferon- This is the process by which before an infected cell is about to die it creates a protein called interferons. These proteins interfere with the growth and replication of the virus which slows down the process of infection. The interferons also send signals to nearby cells which triggers the immune system bringing in white blood cells to destroy the virus.
Antibodies- these are proteins released from plasma cells that are created to bind to antigens. When different antigens enter the host's cells, different antibodies are produced to attach themselves to that specific antigen. Once the antibodies have attached themselves to antigens, many antibodies clump together, and deactivate the pathogens. The antibodies bind with one another because this allows the white blood cells to eat many at one given time. Antibodies are shaped like a "Y" and have small changes at each binding site which allows most antigens to bind with an antibody.
4. 3 methods bacteria alter its genetic information
1. Transduction- This is the process when a virus (bacteriophage) carrying bits of bacterial DNA from its previous host gets injected into a new host. Thus the foreign bacterial DNA then gets incorporated into the new bacteria cell's genetic material which may add new genes and change traits about the new bacterium. However, this does not always happen as most times when a virus is replicating it doesn't contain any bacterial DNA which when passed on to a new bacterium new genes wouldn't get added.
2. Conjugation- This is the process in which bacterium directly transfer genes/genetic material to one another. When conjugation takes place a hollow bridge is created between 2 bacteria cells and a plasmid which contains genetic material gets passed through to the other bacteria. This process increases genetic diversity in bacteria populations.
3. Transformation- This is the process in which once a bacteria cell bursts open, a living bacteria cell can absorb or take in short strands of DNA from the burst cell . Once the bacteria cell takes in the genetic information it then gets placed into its chromosome and can potentially add new genes it hadn't already had.
5. Antibiotic resistance
From the beginning scientists believed antibiotics could cure almost any infectious disease. However, today and from the 19th century these "super bugs" are out smarting us and are becoming harder to kill. When these super bugs break out in areas you may think that they can easily be detained, but thanks to cheap travel these bugs are able to quickly spread from continent to continent. When antibiotics are used, they kill off bacteria but sometimes the most resistant bacteria survives which it will then reproduce and become even more resistant to antibiotics due to mutations. All of these reasons all relate to us as humans as to how we handle these problems. People today are carelessly using antibiotics for problems that don't require them. Now you may think that this wont harm anything but actually by using them too often it gives them a greater chance that they will become resistant to antibiotics. Then one day when you actually need antibiotics you will have developed resistant bacteria which wont die off from the antibiotics. Humans are also contributing to the development of super bugs by not finishing a proper amount of drugs. Say someone feels better after 4 days of drugs and thinks they have killed off the drug. Sometimes some bacteria survive which are the most resistant and will then mutate and reproduce becoming more resistant to what they were originally taking. Overall, through time antibiotic resistance occurs naturally but thanks to humans and their technology it is occurring much more rapidly than we want.