Biology Unit 1 The Flu
Reproduce
Although they can't reproduce asexually or with each other, viruses do reproduce by hijacking a regular cell to create more viruses.
Host Cell
Living cell in which a virus can actively multiply or in which a virus can hide until activated by environmental stimuli
T lymphocytes
Which are white blood cells produced in the bone marrow.
pathogen
a bacterium, virus, or other microorganism that can cause disease
Influenza
flu virus
Macrophages
A large white blood cell that has the ability to locate and "eat" particles, such as bacteria, viruses, fungi, and parasites. Macrophages are born from white blood cells called monocytes, which are produced by stem cells in our bone marrow.
List when an ELISA would be useful.
ELISAs, or an enzyme-linked immunosorbent assay, is a test that detects the presence of antibodies in liquid samples. One common ELISA test is a home pregnancy test. They can also be used for disease detection in people, animals, and plants. They also can detect illegal drug use, test indoor air quality, and determine if food is labeled accurately.
protective proteins
One variety of these are called complement proteins, which act as molecular tags that identify pathogens for destruction by the immune system.
Explain how vaccines prepare our immune systems for pathogens
Vaccines introduce the body to the virus. The body then learns how to fight this virus and when it comes back, the body is able to fight it off quicker.
Transmission
The way a microbial organism moves from one host to another.
Antigen
a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.
5 characteristics of life
1) Process energy and materials. 2) Maintain an internal environment. 3) Respond to stimuli from the environment. 4) Reproduce. 5) Adapt to changing environmental conditions.
Memory cells
B cells that were not activated to create antibodies and thus wait for future exposure to the same infection so the response time will be quicker.
B-Cells
Cells manufactured in the bone marrow that create antibodies for isolating and destroying invading bacteria and viruses.
Describe how you would analyze a blood sample for a pathogen.
If I were to analyze a blood sample for a pathogen, I would have a few things: A blood sample with no pathogen A blood sample with the pathogen (untouched original sample) A blood sample with the pathogen with a detection agent A blood sample that 100% has the pathogen.
mutations
Mutations occur in viruses when their genetic "message" is altered in some way. In the case of influenza, its RNA is easily changed because of its lack of a proof-reading function. This means that any mistakes that happen during the copying of the viruses genetic code during replication go unnoticed, and thus the structure of the virus is changed.
Process energy and materials
They attack cells and use their "energy" to create more viruses.
Virus
a biological agent that reproduces inside the cells of living hosts
Innate immune response
barriers to entry, protective proteins, phagocytes and natural killer cells, and inflammatory response
Adaptive immune response
cell mediated immunity and antibody mediated immunity
Primary response
first time the immune system combats a particular foreign substance
DNA
A complex molecule containing the genetic information that makes up the chromosomes. Double stranded
Vaccine
A harmless variant or derivative of a pathogen that stimulates a host's immune system to mount defenses against the pathogen
viral envelope
A membrane that cloaks the capsid that in turn encloses a viral genome.
phagocytes and natural killer cells
A phagocyte is a type of cell capable of engulfing and absorbing bacteria and other small cells and particles
Interpret the results of an ELISA test.
After making 3 trials of each, I would check to see if the blood sample tested positive for having the pathogen. I would do this by comparing the three samples with the detection agent inside with the blood sample that was 100% infected. If they match, I would know that the blood sample was contaminated with the pathogen.
antibody-mediated immunity
Antibody mediated immunity (AMI) is also called as humoral immunity. ... Binding of antibody to an antigen on a microorganism activates the complement system by opsonization of bacteria, leading to phagocyctosis by cells; and neutralization of toxins released by bacteria.
Antigenic Drift
Antigenic drift occurs when there are small changes in the surface spikes of the influenza virus. This happens because of the lack of an "RNA proof-reader." Our immune systems are usually able to recognize the virus, but with a reduced level of efficiency, meaning that local outbreaks are still possible. One of the biggest problems with antigenic drift is that it can make the annual flu vaccine less effective if the virus mutates after the vaccine has been developed.`
Antigenic Shift
Antigenic shift occurs when two forms of a virus infect the same cell. This often then produces a new form of the virus that we've never seen before. Usually this happens when a different animal host, such as a pig or bird, contracts more than one strain. The problem with this is that it causes a more rapid change in the virus, and since our immune systems have not been exposed to the new form, an outbreak is easier to happen.
Lymph nodes
Bean-shaped filters that cluster along the lymphatic vessels of the body. They function as a cleanser of lymph as wells as a site of T and B cell activation
Explain to someone else why a robust immune system is our best defense against disease
Because we will have multiple things throughout our body trying to fight off the disease and keep us healthy. We have the innate immune response and the adaptive immune response which both have different parts to help protect our body's from disease.
inflammatory response
Damaged tissues and nearby immune cells release histamine, which not only causes fluid to leak from nearby capillaries, thus slowing the movement of pathogens, but also increase blood flow to the area to deliver additional white blood cells (such as macrophages) and clotting factors to repair the wound. The macrophages identify and destroy any bacteria or viruses in the wound area. Neutrophils remove dead cells, wound debris and any pathogens in the area by phagocytosis. If additional assistance is needed, neutrophil may release cytokines to recruit more immune cells to the area. Clotting factors close off the wound. This causes pressure to build and accounts for the red, tender appearance of inflammation.
H and N spikes
H and N spikes are a type of glycoprotein, and are referred to as viral spikes
Explain the future of viral medicine - antivirals and a universal flu vaccine. What do each target and how are they different from the vaccines we use now?
One way to combat a virus that has the ability to rapidly evolve is to target its life cycle. Typically, one of the following three aspects of the viral life cycle is targeted: Attachment: Viruses are specific in the types of cells they infect. Therefore, it is possible to target either the molecules on the surface of the host cell that the virus identifies with or the proteins that the virus uses to attach to the cell. Uncoating: Once inside the cell, some viruses provide an enzyme to remove their genetic material from the capsid. Release: Many viruses provide an enzyme that interacts with specific molecules in the host cell's membrane to allow the newly formed viruses to escape the host cell. Antiviral medications target one of these stages to stop the virus from spreading. For example, Tamiflu targets the release stage of the flu life cycle by inhibiting a viral enzyme, called neuraminidase, that allows the virus to leave the host cell. One issue with the flu is that it seems impossible to make a universal vaccine for it. However, newer vaccines are being designed to use other proteins within the capsid of the virus as the basis for programming the adaptive response. These proteins, sometimes called core proteins, do not change at the same rate as H and N spikes, so they would be easier to target with one vaccine that would work long term.
Explain why you need an annual flu shot
Since influenza uses RNA, it easily mutates and changes. Since the viral spikes on the viruses change so often, the antibodies that body produced to take care of the last strain are ineffective. Antigenic shift is the cause of most of these changes. Scientists create a new vaccine each year based on predictions on what the next flu mutation will be, and they do this by taking samples of those with the flu all over the world. The H and N spikes of influenza are antigens, which means that they're recognized by the immune system and are capable of triggering an immune response, including the production of antibodies that can block an infection.
barriers to entry
Skin: Normal bacteria (flora) on the surface, along with chemicals released by oil and sweat glands, inhibit bacterial growth Respiratory Tract: Mucous membranes trap microbes; they contain chemicals that protect against pathogens; cilia Stomach: Hydrochloric acid (low pH) destroys bacteria and other pathogens
Antibodies
Specialized proteins that aid in destroying infectious agents
Explain why the flu makes you feel miserable
The main reason that influenza causes people to get sick is because the flu's main target are the epithelial cells lining the respiratory system. Epithelial cells form the boundary, called the epithelium, between the tissues of our bodies and internal environments (essentially the skin of the inside of our body). These cells play a very important role in regulating the activities of the body because any substances that enter or leave the body must pass through them before entering the bloodstream and other body tissues. Influenza disrupts these functions, which accounts for many flu symptoms.Most flu symptoms are not the direct result of the influenza virus, but are due to the body's response to the virus, which is the activation of the immune system. This is mainly because of the chemical signals released by the immune system in response to an infection. The white blood cells of the immune system release proteins called cytokines. Cytokines act as an alarm to the organ systems of the body, alerting them that a pathogen is present.
Explain to someone else basic ideas of evolution, especially by natural selection
The scientific term for evolution refers to changes in a species or population over time. Darwin's Theory of Natural Selection states that: Individuals vary in their traits, Individuals struggle to exist, Individuals differ in their fitness (reproductive success), and Populations become adapted to the environment. Certain traits that help a species survive and reproduce are often passed down to newer generations because those with those traits are the ones that survive and reproduce. The "good" traits are transmitted through DNA.
Describe how viruses attack cells
The virus first uses the proteins on its capsid, which each have complex shapes, to target specific molecules on the surface of the target cell. Viruses then use their H and N spikes to enter the cell. After the virus is in the host cell, either by ejecting its genetic material or being engulfed by the host cell, the virus infects the host cell. The virus hijacks the host cell and uses it to manufacture new capsid proteins and copies of the virus's genetic material. After the manufacturing is finished, the pieces of the virus are assembled, and the new viruses are released from the host cell. This happens when either the host cell bursts (lysis) or by leaving through the plasma membrane (exocytosis). Viruses that possess an outer envelope leave by exostosis. As they exit, they often create an envelope around themselves by acquiring pieces of the host cell's plasma membrane.
Secondary response
This is a result of the primary response. Memory cells are activated when the body is exposed to a virus that has already been eliminated, and since you save time in the detection and production processes, the virus is taken care of faster.
Maintain an internal environment
Viruses do not achieve this because they rely on an outside source to maintain functionality.
Respond to stimuli from the environment
Viruses interact with their environment, and are affected by the cells around them.
Adapt to changing environmental conditions
Viruses like the flu are able to adapt to their environment with their ability to quickly evolve due to their RNA.
cell mediated immunity
is an immune response that does not involve antibodies. Rather, cell mediated immunity is the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to antigen.
RNA
single-stranded nucleic acid that contains the sugar ribose
viral capsid
the protein shell, which may or may not contain viral enzymes function: acts to package the nucleic acids so they can be delivered to a new host cell