Table of Contents
How does HIV infect at cell?
When HIV infects a cell, it first attaches to and fuses with the host cell. Then the virus uses the host cell’s machinery to convert the viral RNA into DNA and replicate itself. The new copies of HIV then leave the host cell and move on to infect other cells.
What is the role of ribosomes and Golgi apparatus in HIV infection?
The short spliced RNAs are transported to the cytoplasm where the ribosomes and golgi apparatus use the code to construct viral proteins. Color the golgi apparatus (q) light blue. The longer splices are the full length viral RNA and will become the core of new viruses.
Which type of cells does HIV infect and hide in during latency?
It is truly amazing that the virus can give rise to AIDS 20 years after the initial infection,” Cohn says. Researchers think the reservoir of latent virus may be hiding out in a type of CD4 T cell: long-lived memory cells that help the immune system remember particular pathogens.
Is HIV single or double stranded?
The HIV genome consists of two identical single-stranded RNA molecules that are enclosed within the core of the virus particle.
What happens to organelles when a virus attacks a cell?
Then the viral genome hijacks the host cell’s machinery, forcing it to replicate the viral genome and produce viral proteins to make new capsids. Next, the viral particles are assembled into new viruses. The new viruses burst out of the host cell during a process called lysis, which kills the host cell.
What organelle protects cells from invading viruses?
The researchers have identified that MxB is an inner mitochondrial membrane GTPase, which plays a pivotal role in the form or shape and function of the mitochondria. The proteins help cells protect themselves and fight infections without using systemic antibodies or white blood cells.
What breaks down toxins and poisons in a cell?
Peroxisomes chemically neutralize poisons through a process that produces large amounts of toxic H2O2, which is then converted into water and oxygen.
What are the 4 main ways viruses cause tissue damage?
Direct cell damage and death from viral infection may result from (1) diversion of the cell’s energy, (2) shutoff of cell macromolecular synthesis, (3) competition of viral mRNA for cellular ribosomes, (4) competition of viral promoters and transcriptional enhancers for cellular transcriptional factors such as RNA.
How do antibodies destroy pathogens?
The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies. Antibodies attach to an antigen and attract cells that will engulf and destroy the pathogen.
How do viruses infect cells answers?
DNA released into the cell integrates with the cell’s DNA. From there, the virus controls the cell and makes the cell produce more virus particles. When the process is completed, the cell will release the new viruses which will then infect other cells.
How do cells defend against a virus?
Virally infected cells produce and release small proteins called interferons, which play a role in immune protection against viruses. Interferons prevent replication of viruses, by directly interfering with their ability to replicate within an infected cell.
How does the cell wall protect against viruses?
When cells are confronted with an invading virus or bacteria or exposed to an irritating chemical, they protect themselves by going off their DNA recipe and inserting the wrong amino acid into new proteins to defend them against damage, scientists have discovered.
How do viruses defend themselves?
Viral infection When infected, a cell sends out a chemical alarm called interferon. In response, neighboring cells ramp up production of Mx proteins. These proteins block entry into the nucleus, preventing a virus genome from replicating.
How do toxins enter cells?
The toxins bind to receptors on the surface of susceptible cells and enter them by endocytic uptake. With the exception of pore-forming protein toxins, which compromise the permeability barrier of the target cell plasma membrane, the bacterial toxins act catalytically to modify substrates within mammalian cells.
How do chemicals enter cells?
Chemicals can enter the human body by several methods, but most must pass through living cell membranes before entering the bloodstream. Mechanisms for moving chemicals through the cell membrane include: passive diffusion, facilitated diffusion, active transport, and endocytosis.
What are the two types of toxicity?
The two types of toxicity are acute and chronic. Acute toxicity of a pesticide refers to the chemical’s ability to cause injury to a person or animal from a single exposure, generally of short duration. The four routes of exposure are dermal (skin), inhalation (lungs), oral (mouth), and eyes.
How does a virus damage cells?
Most viral infections eventually result in the death of the host cell. The causes of death include cell lysis, alterations to the cell’s surface membrane and various modes of programmed cell death. Some viruses cause no apparent changes to the infected cell.
How does a virus leave a cell to infect other cells?
Many animal viruses, such as HIV (human immunodeficiency virus), leave the infected cells of the immune system by a process known as budding, where virions leave the cell individually. During the budding process, the cell does not undergo lysis and is not immediately killed.
What are the 5 stages of viral replication?
Most productive viral infections follow similar steps in the virus replication cycle: attachment, penetration, uncoating, replication, assembly, and release.
How does antibody destroy antigen?
Each antibody has a unique binding site shape which locks onto the specific shape of the antigen. The antibodies destroy the antigen (pathogen) which is then engulfed and digested by macrophages.
How do antibodies inactivate antigens?
Antibodies attack antigens by binding to them. The binding of an antibody to a toxin, for example, can neutralize the poison simply by changing its chemical composition; such antibodies are called antitoxins.
How do antibodies destroy cells?
1) Antibodies are secreted into the blood and mucosa, where they bind to and inactivate foreign substances such as pathogens and toxins (neutralization). 2) Antibodies activate the complement system to destroy bacterial cells by lysis (punching holes in the cell wall).
How does a virus infect?
Once inside the body, a virus infects a host cell by injecting its genetic material.
How do viruses enter cells?
Virus entry into animal cells is initiated by attachment to receptors and is followed by important conformational changes of viral proteins, penetration through (non-enveloped viruses) or fusion with (enveloped viruses) cellular membranes. The process ends with transfer of viral genomes inside host cells.
Why Do viruses have to infect host cells?
Virus. A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. A virus cannot replicate alone. Viruses must infect cells and use components of the host cell to make copies of themselves.
