Viruses vs. Cells
Comparing and Contrasting
By: Holly Bowling
Human Immunodeficiency Virus
Lytic Cycle and Lysogenic Cycle
The left side (red color) is the Lytic Cycle, which is the fastest cycle. The bacteria attaches to a cell, enters it, replicates with the cell, assembles, and then kills the host cell and moves on the other cells to infect. An example of this cycle is bacteriophage lambda.
The right side (blue color) is the Lysogenic Cycle, which is longer. Basically once you have a disease/virus with this you will have it forever. The virus or whatever it is stays dormant and then its triggered, then it will react and show. So again, the bacteria attaches, enters, then gives its DNA to the host( host now has its own DNA plus the virus), it is then copied (reproduces), and then will become dormant. An example of this cycle is Herpes Virus.
8 Characteristics of Life
1. Living things grow and develop
2. Respond to their environment
3. All living things have DNA
4. Living things are made up of cells
6. Living things maintain homeostasis
7. Living things obtain, use material and energy
8. Living things evolve
Viruses are techniqually not considered living because the only characteristics they follow are that they have DNA/RNA and they evolve. Viruses do not grow and develop, respond go their environment, they are most certainly not made up of cells(they infect cells), the only way they can reproduce is with a cell present(cannot reproduce own their own), do not maintain homeostasis and obtain, use material and energy.
1. 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 contains a Capsid (protein layer), Genetic Material, and Envelope (lipid membrane). Viruses are made up of protein (capsid), DNA, and the envelope. The biomolecules you would find in a virus are nucleic acids and proteins.
2. Discuss the different ways viruses gain energy.
Viruses do not need direct energy; so they use the host cell's energy to reproduced. They use the metabolic machinery of the host; viruses are passive.
3. Explain why the Ebola virus would not infect a tobacco plant.
Viruses can only infect animals and humans. There has been a discovery that tobacco plants can heal the virus.
4. Name five viruses and the type of cell that they attack.
-Chickenpox; sensory nerve cells
-Mononucleosis; the liver, lymph nodes and oral cavity
-Herpes; skin cells
-West Nile Virus; central nervous system
5. 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.
The doctor will not give you antibiotics because once the body is infected with the disease it takes action right a way. You have to let the flu run its course and let the body handle it. Antibiotics do not work on viruses.
6. How is it that a person can be infected with a virus such as HIV and not exhibit symptoms?
HIV symptoms can be nonexistent for up to 10 years, so the only way to know if you have HIV is to get tested.