When the pandemic started, I realized I didn’t know much about viruses. So, I did some research and summed up what I found in nine simple images.
Viruses are everywhere on Earth, making them the most common form of life. However, they’re not considered living because they can’t reproduce on their own. Instead, they invade host cells and use their machinery to make more viruses. There are millions of virus types, but only about six thousand have been studied in detail. Viruses can infect animals, plants, bacteria, and even archaea, using different methods to do so.
Every virus has a genome, which is like a set of instructions for making more viruses, and a protective protein shell called a capsid. Some viruses also have an envelope, which they get from the membrane of the last cell they infected.
Viruses are tiny, usually around 20 nanometers, which is about a thousand times smaller than a human cell. Their genomes can be small, coding for just two proteins, or large, coding for up to 2,500 proteins. Viruses are classified based on their genetic material, which can be DNA or RNA, and whether it’s single-stranded or double-stranded. They also come in different shapes, like helical, icosahedral, prolate, complex, and enveloped forms.
The Baltimore classification system sorts viruses based on their genome and how they produce messenger RNA (mRNA). For instance, the coronavirus from the 2020 pandemic is an enveloped virus in class four, while the seasonal flu is in class five.
Viruses get into cells in three main ways:
Once inside, viruses take over the host cell’s machinery to replicate. RNA viruses usually replicate in the cytoplasm, while DNA viruses do so in the nucleus. The host cell unknowingly makes viral proteins and new viral genomes. Viruses can leave cells through apoptosis, budding, or exocytosis. Some can stay dormant inside cells for a long time, a state known as latency.
Most viruses are adapted to specific species, but some, like rabies, can infect multiple species when they mutate. Our immune system fights viruses with T-helper cells and antibodies produced by B cells. Vaccines help prevent viral infections by triggering an immune response without causing illness.
When vaccines aren’t available, antiviral drugs can treat infections, though creating these drugs is tough because viruses mutate quickly.
For more information, check out the links in the video description. Thanks for your support, and I hope to share more scientific content soon!
Use craft materials to build a 3D model of a virus. Include the genome, capsid, and envelope if applicable. This will help you visualize the structure of viruses and understand their components better.
Research different viruses and classify them using the Baltimore classification system. Create a chart that includes the virus name, genome type, and class. This activity will reinforce your understanding of how viruses are categorized.
In groups, role-play the process of a virus entering a cell, replicating, and exiting. Assign roles such as virus, cell membrane, and host cell machinery. This interactive activity will help you grasp the viral life cycle.
Simulate an immune response to a viral infection. Use props to represent T-helper cells, antibodies, and viruses. This will give you a practical understanding of how the immune system fights viruses.
Choose a virus and research how a vaccine for it works. Present your findings to the class, explaining the vaccine’s mechanism and its role in preventing infections. This will deepen your knowledge of viral prevention strategies.
Here’s a sanitized version of the provided YouTube transcript, with unnecessary details and informal language removed for clarity and conciseness:
—
At the beginning of the pandemic, I realized I didn’t know much about viruses, so I conducted research and summarized my findings in nine images.
Viruses are the most abundant form of life on Earth, but they are not considered living organisms because they cannot reproduce independently. They invade host cells to utilize their molecular machinery for reproduction. There are millions of different types of viruses, but only about six thousand have been studied in detail. Viruses can infect a wide range of organisms, including animals, plants, bacteria, and archaea, and they vary significantly in their mechanisms of infection.
All viruses contain a genome, which provides the instructions for making more viruses, and a protective protein shell called a capsid. Some viruses also have an envelope, which is derived from the membrane of the last cell they infected.
Viruses are incredibly small, typically around 20 nanometers in size, making them about a thousand times smaller than an average human cell. Their genomes can vary in size, coding for as few as two proteins to as many as 2,500.
Viruses can be classified based on their genetic material, which can be DNA or RNA, and whether it is single-stranded or double-stranded. They also come in various shapes, including helical, icosahedral, prolate, complex, and enveloped forms.
The Baltimore classification system categorizes viruses based on their genome and the pathway to producing messenger RNA (mRNA). For example, the coronavirus responsible for the 2020 pandemic is an enveloped virus classified as a class four virus, while seasonal influenza is classified as a class five virus.
Viruses enter cells primarily through three methods:
1. Enveloped viruses attach to cell receptors and fuse with the membrane.
2. Non-enveloped viruses trick the cell into engulfing them through endocytosis.
3. Some viruses inject their genetic material directly into the cell.
Once inside, viruses replicate by hijacking the host cell’s machinery. RNA viruses typically replicate in the cytoplasm, while DNA viruses replicate in the nucleus. The host cell unknowingly transcribes the viral genetic material, producing viral proteins and new viral genomes.
Viruses can exit cells through apoptosis, budding, or exocytosis. Some viruses can remain dormant within cells for extended periods, a state known as latency.
Viruses have varying ranges of infection, with most adapted to specific species. Some viruses, like rabies, have a broader range and can cross species barriers when they mutate.
Our immune system has sophisticated mechanisms to combat viral infections, including the activation of T-helper cells and the production of antibodies by B cells. Vaccines are effective in preventing viral infections by stimulating an immune response without causing disease.
In cases where vaccines are not available, antiviral drugs can be used to treat infections, although developing these drugs is challenging due to the rapid mutation of viruses.
For more information, please refer to the links in the video description. Thank you for your support, and I hope to provide more scientific content soon.
—
This version maintains the essential information while removing informal language and extraneous details.
Viruses – Small infectious agents that can only replicate inside the living cells of an organism. – Scientists study viruses to understand how they cause diseases and how they can be controlled.
Genome – The complete set of genes or genetic material present in a cell or organism. – The human genome project mapped all the genes in human DNA to better understand genetic diseases.
Capsid – The protein shell that surrounds and protects the genetic material of a virus. – The capsid of a virus plays a crucial role in its ability to infect host cells.
DNA – Deoxyribonucleic acid, the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms. – DNA is often referred to as the blueprint of life because it contains the instructions needed for an organism to develop and function.
RNA – Ribonucleic acid, a molecule that plays a central role in the synthesis of proteins and can also carry genetic information in some viruses. – Some viruses, like the influenza virus, use RNA instead of DNA to store their genetic information.
Classification – The process of grouping organisms based on shared characteristics and giving them a scientific name. – Biological classification helps scientists communicate about different species and understand their relationships.
Infection – The invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body. – The common cold is caused by a viral infection that affects the respiratory system.
Immune – Having resistance to a specific infection or toxin due to the presence of specific antibodies or sensitized white blood cells. – After recovering from chickenpox, a person usually becomes immune to future infections of the same virus.
Vaccines – Biological preparations that provide active acquired immunity to a particular infectious disease. – Vaccines help protect individuals and communities from diseases by stimulating the immune system to recognize and fight pathogens.
Treatment – The management and care of a patient for the purpose of combating a disease or condition. – Antibiotics are a common treatment for bacterial infections, but they do not work against viruses.
