Viruses vs Cells
By: Chloe Bergman
HIV
Influenza
Bacteriophage Virus
Plant Cell
Animal Cell
Lytic Cycle
In the picture above, the lytic cycle is shown. Number one is showing the first step of the lytic cycle, when the virus attaches itself to a cell. Number two shows the virus, which has attached itself, inserting its DNA. In number three, the host cell is copying that DNA that the virus inserted into it. Number four is showing how the new viruses are crowding the cell before the cell bursts and sends the viruses out to infect other cells in number five.
Lysogenic Cycle
The lysogenic cycle also includes the Lytic cycle. It starts with a virus attaching itself to a cell. Then the virus's DNA is incorporated with the cell's DNA. Once the cell divides, each of the daughter cells have the virus's DNA and that is when the lytic cycle begins
Characteristics of Life
1) grow and develop
2) have DNA
3) respond to the environment
4) have cells
5) reproduce
6) maintain homeostasis
7) obtain and use materials and energy
8) evolve as a group
Characteristics of Life in Viruses
The characteristics that viruses don't have include reproduction, have cells, and obtain and use materials and energy. Viruses cannot reproduce on their own, they rely on cells to reproduce. Viruses also do not have cells or eat.
The characteristics that viruses do have include grow and develop, have DNA, and evolve as a group. Viruses are some of the fastest growing and developing organisms. Viruses also have DNA which is covered by a capsid and sometimes another layer made of lipids.
Questions
Describe the typical structure of a virus. What is a virus made of? What biomolecules would you find in a virus?
The structure of a virus includes DNA or RNA surrounded by a protein coat called a capsid and some enzymes. Sometimes viruses have a lipid membrane around the capsid called an envelope.
Viruses have the biomolecules Nucleic Acid, because of their DNA and RNA, Protein, because of the protein coat, and Lipids, because of the envelope.
Discuss the different ways viruses gain entry into a cell
In order to gain entry into their host cell, the virus must access the cytoplasm without destroying the host cell. There are different entry mechanisms depending of the type of host and the type of virus.
Explain why the Ebola virus would not infect a tobacco plant
The Ebola virus would not infect a tobacco plant because viruses are very specific things and their outer layer will only allow itself to attach to certain cell membranes.
Name five viruses and the type of cell they attack
The HIV virus attacks T cells
The flu virus attacks epithelial cells
Rabies attacks nervous system cells
The herpes virus attacks epithelial cells
Chickenpox attacks cells in the sensory nerves
You have been diagnosed with the flu. Explain why a doctor will not provide you with a prescription for antibiotics in order to cure your infection.
Antibiotics are used to treat bacterial diseases, not viral diseases, and the flu is a viral disease. Using antibiotics to treat the flu virus will not work.
How is it that a person can be infected with a virus such as HIV and not exhibit symptoms?
The HIV virus kills T Cells, which are used in the body to destroy disease cells that cause the body to get sick. If somebody gets sick while they have HIV, there are not enough T cells to help fight off the infection and therefore could die from a simple cold. A person with HIV may not be sick and in need of the use of T Cells, therefore not showing the symptoms.