science

Adenoviridae

Adenoviridae is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Adenoviridae rather than just read about it. In short: Adenoviruses (members of the family Adenoviridae) are medium-sized (90–100 nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953.

Key takeaways

Adenoviridae belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Adenoviridae to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Adenoviridae from memory before moving on to harder problems.

Reference excerpt

Adenoviruses (members of the family Adenoviridae) are medium-sized (90–100 nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953. They have a broad range of vertebrate hosts; in humans, more than 50 distinct adenoviral serotypes have been found to cause a wide range of illnesses, from mild respiratory infections in young children (the common cold) to life-threatening multi-organ disease in people with a weakened immune system.

Virology

Classification This family contains the following genera:

Aviadenovirus Barthadenovirus Ichtadenovirus Mastadenovirus (including all human adenoviruses) Siadenovirus Testadenovirus

Diversity In humans, currently there are 88 human adenoviruses (HAdVs) in seven species (Human adenovirus A to G):

A: 12, 18, 31 B: 3, 7, 11, 14, 16, 21, 34, 35, 50, 55 C: 1, 2, 5, 6, 57 D: 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 33, 36, 37, 38, 39, 42, 43, 44, 45, 46, 47, 48, 49, 51, 53, 54, 56, 58, 59, 60, 62, 63, 64, 65, 67, 69, 70, 71, 72, 73, 74, 75 E: 4 F: 40, 41 G: 52 Different types/serotypes are associated with different conditions:

respiratory disease (mainly species HAdV-B and C) conjunctivitis (HAdV-B and D) gastroenteritis (HAdV-F types 40, 41, HAdV-G type 52) obesity or adipogenesis (HAdV-A type 31, HAdV-C type 5, HAdV-D types 9, 36, 37) All these types are called Human mastadenovirus A–G by the ICTV, because all are members of the genus Mastadenovirus.

Structure

Adenoviruses are medium-sized (90–100 nm). The virions are composed of one linear piece of double-stranded DNA inside an icosahedral capsid. 240 hexon proteins make up the bulk of the capsid, while twelve penton bases cap the icosahedron's corners. The penton bases are associated with protruding fibers that aid in attachment to the host cell via the receptor on its surface. In 2010, the structure of the human adenovirus was solved at the atomic level, making it the largest high-resolution model ever. The virus is composed of around 1 million amino acid residues and weighs around 150 MDa.

Genome

The adenovirus genome is linear, non-segmented double-stranded (ds) DNA that is between 26 and 48 kbp. This allows the virus to theoretically carry 22 to 40 genes. Although this is significantly larger than other viruses in its Baltimore group, it is still a very simple virus and is heavily reliant on the host cell for survival and replication. The genes of adenoviruses can generally be divided into well-conserved sets of transcription units with six early transcription units (E1A, E1B, E2A, E2B, E3 and E4) and one late transcription unit ranging from L1-L5. In addition, adenoviruses also contain two intermediate transcription units named XI and IVa2. To increase the viral gene economy, adenoviruses accommodate genes on both strands of its dsDNA meaning that most of its genome is utilized for coding proteins. An interesting feature of this viral genome is that it has a terminal 55 kDa protein associated with each of the 5' ends of the linear dsDNA. These are used as primers in viral replication and ensure that the ends of the virus' linear genome are adequately replicated.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Adenoviridae

Start with the simplest possible case. Write down what Adenoviridae claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Adenoviridae before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Adenoviridae ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Adenoviridae

In research: Adenoviridae appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Adenoviridae in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Adenoviridae is common in secondary-school and first-year university syllabi. It links to neighbouring topics Adenoviridae, Virus families, so understanding it makes those chapters shorter.
In everyday life: Look for Adenoviridae outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Adenoviridae in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Adenoviridae means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Adenoviridae out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Adenoviridae in simple terms?

Why does Adenoviridae matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Adenoviridae?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Adenoviridae.