GIZMO Virus Lytic Cycle Student Exploration Sheet

Exam (elaborations) GIZMO Virus Lytic Cycle Student Exploration Sheet Student Exploration: Virus Lytic Cycle Vocabulary: bacteriophage, capsid, host cell, lyse, lytic cycle, virus Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. A computer virus is a program that can copy itself and infect a computer without the permission of the owner. How do you think a computer virus compares to a real virus? A computer virus infects a computer, and a real virus infects an organism. During an infection, both types of viruses make copies of themselves so that more infections can occur. A computer viruses disrupts the functions of a computer, while a real viruses destroys its host cells. 2. Have you ever been infected with a virus, such as the cold virus or flu virus? yes 3. If so, how did the virus affect you? The viruses affected me by giving me fevers and congestions. Gizmo Warm-up A virus is a microscopic particle that can infect a cell. Viruses are primarily composed of a protein coat, called a capsid, and nucleic acid. In the Virus Lytic Cycle Gizmo™, you will learn how a virus infects a cell and uses the cell to produce more viruses. 1. Viruses are extremely small. A typical virus is about 100 times smaller than a single cell, such as a bacterium. 2. Bacteriophages are viruses that infect bacteria. This study source was downloaded by from CourseH on :31:46 GMT -05:00 This study resource was shared via CourseH GIZMO Virus Lytic Cycle Student Exploration Sheet 2019 Activity A: Lytic cycle Get the Gizmo ready:  If necessary, click Reset ( ). Introduction: Unlike living organisms, viruses cannot reproduce on their own. Instead, viruses infect host cells, taking over the cell’s machinery to produce more viruses. This process is called the lytic cycle. Question: What are the steps of the lytic cycle? 1. Observe : Use the navigation arrows on the DESCRIPTION tab to read about the stages of the lytic cycle. Using your own words, summarize each step of the cycle. Step Summary 1 A lytic bacteriophage virus attaches itself to a bacterial cell. The virus is a very simple structure, composed of a protein capsid, nucleic acid, and a tail section. ↓ 2 The virus injects its nucleic acid into the cell. The nucleic acid uses the cell’s ribosomes to make virus proteins. The proteins break up the cell’s DNA. ↓ 3 The virus capsid and tail, now useless, detach from the cell and disintegrate. Inside the cell, the viral nucleic acid takes over and directs the production of new virus proteins and nucleic acid ↓ 4 The virus proteins and nucleic acid assemble into new viruses. ↓ 5 Special proteins produced by the viral nucleic acid cause the host bacterial cell to lyse (burst), destroying the cell in the process. The numerous new viruses are now free to infect other cells. (Activity A continued on next page) This study source was downloaded by from CourseH on :31:46 GMT -05:00 This study resource was shared via CourseH 2019 Activity A (continued from previous page) 2. Analyze : The yellow ring inside the bacterial cell represents the bacterial DNA. Why does this structure disappear by step 3 of the lytic cycle? In step 2, the viral nucleic acid takes over control of the cell by destroying the host cell’s DNA. 3. Describe : How does a virus destroy the host cell’s DNA? The viral nucleic acid uses the cell’s ribosomes to make proteins and these proteins break up the bacterial cell’s DNA. 4. Describe : How are new viruses reproduced? Viral nucleic acid takes control of a cell’s mechanisms, including the structures the cell uses to make proteins and copy nucleic acid. The viral nucleic acid uses these mechanisms to make new viruses parts then the parts assemble into new viruses. 5. Think and discuss : Why can’t a virus reproduce on its