Once infected the t helper cell turns into an hiv replicating cell. How hiv infects cells worksheet for 8th 9th grade lesson. Lesson hiv structurelife cycle 2 and implications for. X4 virus preferentially infects naiveactivated t cells biology. Hiv is a retrovirus, which means it carries singlestranded rna is its genetic material rather than the doublestranded dna human cells carry. There are typically 1 million t cells per one milliliter of blood. When hiv destroys this cell, it becomes harder for the body to fight off other infections. The hiv human immunodeficiency virus has a lipid membrane similar to the cell. Like all viruses, hiv is not able to reproduce or express its genes without the help of a living cell. Answer key hiv webquest morgridge institute for research. It infects cells with a particular surface receptor.
Retroviruses also have the enzyme reverse transcriptase, which allow it to copy rna into dna and use that dna copy to infect human, or host, cells. Reduction in the number of thelper cells weakens the immune system, ultimately leading to acquired immunodeficiency syndrome aids, which is characterized by increased bacterial, fungal, and parasitic infections. When the body does not show symptoms of an infection or illness. Ask the students to complete the handout as they listen to the presentation. Most productive viral infections follow similar steps in the virus replication cycle. In general, viruses have very small genomes, which means they can encode a very limited number of their own proteins. The viral core enters the thelper cell, and the virions protein membrane fuses. In this how hiv infects cells learning exercise, learners read the given information about how hiv infects cells. For example, cold and flu viruses will attack cells that line the respiratory or digestive tracts. Retroviruses are distinguished from other types of viruses by two key steps in the. Once infected, the thelper cell turns into an hiv replicating cell. Students explain the role of various structures in hiv infection.
The term avian means bird, and avian flu is adapted to infect birds. In reality we found that how hiv infects cells worksheet answers worksheets weather instruments weather worksheets pdf was being one of the subjects about instances of business archives. Hiv human immunodeficiency virus is composed of two strands of rna, 15 types of viral proteins, and a few proteins from the last host cell it infected, all surrounded by a lipid bilayer membrane. Most people infected with hiv are still healthy and can live for years with. Hiv infects lymphocyte white blood cells called t cells. Macrophages are large white cells whose job it is to clean up foreign material by engulfing it. To do so, hiv uses a veil of human proteins in a trojan horse manner to infect immune cells. List four characteristics that human immunodeficiency virus hiv and ebola virus have in common. Hiv infects a type of white blood cell in the bodys immune system called a thelper cell also called a cd4 cell. List four characteristics that hiv and ebola virus do not share.
Viruses make a person sick when they get into the cells and make more viruses, which kills the cells. Once infect, the thelper cell turns into an hiv replicating cell. The disease can become life threatening due to the risk of the cysts rupturing and may require surgery. For this lesson, it is sufficient for students to understand that hiv directly infects the immune systems cells.
Some viruses can jump species, like the swine flu which originated in pigs and then jumped to human hosts. Explain the role of each of the following in hiv infection protease assembles the viruses from the proteinsreverse transcriptase converts viral rna to dnacd4 receptors where the virus fuses with the t helper cells rna polymerase assembles rnaintegrase fuses viral dna with host. Together, these molecules allow the virus to infect cells of the immune. A person is diagnosed with aids when the person has a very low number of t cells or cd4 cells or shows signs of a serious infection. Lets look at how the hiv virus infects immune system cells and replicates. Sep 12, 20 these structural details should help us understand more precisely how hiv infects cells, and how we can do better at blocking that process with nextgeneration drugs, said beili wu, phd. Hiv will slowly reduce the number of these cells until the person develops the disease aids. Hiv will slowly reduce the number of these cells until the person develops the. Worksheet students read about how hiv infects cells, answer 3 questions, and then color the virus cell parts for 15 keywords.
Hiv becomes part of the cells, and when they multiply to fight an infection, they also make more copies of hiv. Dec 18, 2018 hiv will slowly reduce the number of these cells until the person develops the disease aids. Interestingly, the virus does not typically sicken the wild bird species that carry it. Choosing not to engage in an activity or set of activities. Hiv coloring key denton independent school district. Lets look at how the hiv virus infects immune system cells and replicates binding. Hiv infects a particular type of immune system cell, the t helper cell. How hiv infects a cell international partnership for. Hiv hiv infects helper t cells without t h cells, the patients immune system stops functioning aids patients become very susceptible to other infections. As the number of healthy cd4 tcells decrease, immune function is compromised and its difficult for the immune system to fight infections that a healthy immune system can. Once hiv enters the body, it heads for the lymphoid tissues, where it finds thelper cells source.
List four characteristics that human immunodeficiency virus hiv and ebola virus have in. Of the nine viruses shown, which is the only one that infects bacteria. These vital cells keep us healthy by fighting off infections and diseases. Sdf1cxcr4 responsible for migrationhoming of naive t cells to lymph node. Aug 20, 2018 like all viruses, hiv is not able to reproduce or express its genes without the help of a living cell. Chapter 08 biology of infectious diseases flashcards. How hiv infects a cell international partnership for microbicides. These structural details should help us understand more precisely how hiv infects cells, and how we can do better at blocking that process with nextgeneration drugs, said beili wu, phd. Answer key and coloring guide to the hiv worksheet students read about how hiv infects the cell and color a diagram on the life cycle of a virus. The human immunodeficiency virus hiv, which causes aids, attacks the tcells of the immune system. How hiv infects the body and the lifecycle of hiv avert. Teachers pay teachers is an online marketplace where teachers buy and sell original educational materials. Handson activity viral dna integration overview this activity is part of a series of activities and demonstrations focusing on various aspects of the human immunodeficiency virus hiv life cycle. For example, the chickenpox virus infects humans, but does not infect dogs.
The new viruses then leave the t cell and destroy other healthy t cells as they multiply inside the body. Aug 07, 2018 hiv attacks a specific type of immune system cell in the body. Handson activity viral dna integration student worksheet. First, hiv attaches to the immune cell when the viruss gp120 protein binds with the cd4 protein of the thelper cell. Hiv infection hiv infects a particular type of immune system cell the cd4 t helper cell or just plainly the t helper cell. This strategy hinders the bodys ability to defend itself against the.
These viruses all belong to a group called influenza a viruses. However, the damage to the cells that hiv infects may make it impossible for the cells to function as mediators of immunity, even though the cells remain alive for a period of time. Hiv infects lymphocyte white blood cells called tcells. There are typically 1 million tcells per one milliliter of blood. It can only infect cells on the surface of the body where the temperature is lower. Humans can develop cysts in internal organs, especially the lungs and liver, if they ingest eggs from an infected animal.
Hiv is a disease in which the original clinical observations of severe opportunistic infections gave the first clues regarding the underlying pathology, namely that hiv is essentially an infection of the immune system. Hiv infects and destroys helper t cells of the immune system causing a marked reduction in their numbers. As the number of healthy cd4 t cells decrease, immune function is compromised and its difficult for the immune system to fight infections that a healthy immune system can. It can only infect cells that are actively growing and dividing. Handson activity viral dna integration educator materials. After fusion, the virus releases rna, its genetic material, into the host cell. Hydatid disease is caused by a tapeworm which infects dogs, dingoes and foxes. First, the virus must be able to successfully infect a cell. Instead, the virus attaches itself to a thelper cell and fuses with it. Hiv will slowly reduce the number of these cells until the person. Student worksheet handson activity viral dna integration hhmi. T cells invaded by hiv can no longer fight infections properly. To go from cell to cell, hiv is packaged in an envelope or capsid made from viral proteins and proteins from human cell membranes.
Hiv attacks a specific type of immune system cell in the body. Chapter 08 biology of infectious diseases flashcards quizlet. This how hiv infects cells worksheet is suitable for 8th 9th grade. Hiv webquest answer key morgridge institute for research. Over time, hiv infection weakens a persons ability to fight other infections and some diseases. T cells invaded by hiv can no longer fight infections. Sep 27, 20 how hiv infects cells by argonne national laboratory the structure of the ccr5 cell surface receptor, which most strains of hiv use to enter human immune cells. T cells, are small white blood cells that are critical in immune defense and are hivs principal target. Hiv human immunodeficiency virus is a lentivirus and a member of the retrovirus family. This virus infects several types of cells in the body including a set of white blood cells called thelper t h cells.
Most people in north america get infected by hiv by. Click on these icons and answer the questions below associated with. Published september 2016 page 2 of 6 click and learn virus explorer g. Loss of cd4 cells leads to generalized failure of the immune system and susceptibility to life threatening opportunistic infections. How a virus infects you how viruses work howstuffworks. Answer keys are no longer provided due to an overwhelming number of requests to. In a longawaited finding, a team of chinese and us scientists has determined the highresolution atomic structure of a cellsurface receptor that most strains of hiv use to get into human immune cells. Competes with hiv binding, but not produced in inflammation or by t cells receptor. Begin the activity with a short presentation on hiv infection and aids and will hand out a copy of the hiv infection and aids basics. Someone could choose to abstain from oral, vaginal, and anal sex as a way to reduce the risk of stis. Hiv infects helper t cells by binding to the cd4 receptor on these cells.