Viruses and Prions Chapter 5

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Questions and Answers

What was the first indication that there were infectious agents smaller than bacteria?

Infection of algae

Bodily fluids that were filtered to remove bacteria remained infectious (correct)

Discovery of a virus in tobacco plants

Foot-and-mouth disease in cattle

Viruses can multiply independently without a host cell.

False

What is the diameter range of most viruses?

20nm to 1,000nm

Which of the following best describes a capsid?

The protein shell that surrounds nucleic acid Signup and view all the answers

Match the viral genome types with their strategies:

Class I = dsDNA → mRNA Class II = ssDNA → dsDNA → mRNA Class III = dsRNA → mRNA Class IV = (+) ssRNA → (-) ssRNA → mRNA Class V = (-) ssRNA → mRNA Class VI = ssRNA-RT → DNA/RNA → dsDNA → mRNA Signup and view all the answers

Viruses can infect various organisms including ______.

bacteria, algae, fungi, protozoa, plants, and animals Signup and view all the answers

What classification system describes how each type of virus makes mRNA?

Baltimore Classification System Signup and view all the answers

What is the primary purpose of using artificial intelligence in winemaking according to Katerina Axelsson?

To predict consumer preferences Signup and view all the answers

Artificial intelligence can replace human intuition in winemaking.

False Signup and view all the answers

How many unique wine labels were applied for last year?

126,000 Signup and view all the answers

Grapes do not continue to ripen after being ______.

plucked Signup and view all the answers

What is the title of Katerina Axelsson's company?

Tastry Signup and view all the answers

What did researchers link to grape softening and sugar storage?

metabolites Signup and view all the answers

What technology is being used to sort grapes based on ripeness?

AI-powered grape-sorting machines Signup and view all the answers

What is one factor that shapes wine preferences, aside from palate?

marketing Signup and view all the answers

Study Notes

Discovery of Viruses

Initial identification involved a disease in tobacco plants linked to virus presence.
Foot-and-mouth disease in cattle also attributed to viruses.
Infectious agents smaller than bacteria made evident through filtration of bodily fluids.

Role of Viruses in Evolution

Viruses infect cells and can alter their genetic make-up.
Approximately 8% of the human genome and 10-20% of bacterial genomes consist of viral sequences.

Properties of Viruses

Obligate Intracellular Parasites: Require host cells for replication; lack metabolic enzymes and protein synthesis machinery.
Ubiquitous Infectors: Infect various life forms including bacteria, fungi, plants, and animals, significantly influencing biological development.
Classification: Based on host type, disease caused, structure, and genetic makeup; classified by the International Committee on Taxonomy of Viruses.
Size Range: Typically between 20nm to 1,000nm; most are visible only via electron microscopy.
Status: Descriptive terms “active” or “inactive” used instead of “alive” or “dead” due to their non-living nature.
Host Attachment: High specificity for host attachment is conferred by surface molecules on viruses.

Viral Structure

Capsid: Protein shell encasing nucleic acid.
- Nucleocapsid: Combination of capsid and nucleic acids.
- Capsomeres: Identical proteins forming the capsid structure.
- Types of Capsids: Includes helical, icosahedral, and complex forms.
Envelope: External covering derived from host cell membranes.
- Naked Viruses: Composed solely of nucleocapsid.
- Enveloped Viruses: Can bud from various membranes, flexible structure leads to pleomorphism.
Spikes: Surface projections enabling virus docking on host cells.
Virion: A complete, infectious virus particle.
Nucleic Acids: Composed of either DNA or RNA, never both.
- DNA Types: Can be double or single-stranded.
- RNA Types: More commonly single-stranded; includes positive-sense and negative-sense variants.
- Retroviruses: Unique in producing DNA from RNA using specific enzymes.

Baltimore Classification System

Organizes viruses by their mRNA synthesis mechanisms.

Types of Viral Genomes

Class I (dsDNA): Double-stranded DNA → mRNA (Example: Herpes simplex).
Class II (ssDNA): Single-stranded DNA → double-stranded DNA → mRNA (Example: Parvovirus B19).
Class III (dsRNA): Double-stranded RNA → mRNA (Example: Rotavirus).
Class IV (+) ssRNA: Positive-sense ssRNA → negative-sense ssRNA → mRNA (Example: Poliovirus).
Class V (-) ssRNA: Negative-sense ssRNA → mRNA (Example: Influenza virus).
Class VI (ssRNA-RT): Single-stranded RNA reverse transcribed to DNA/RNA → double-stranded DNA → mRNA (Example: HIV).
Class VII: Double-stranded DNA (Example: Not fully detailed in notes).

Big Data and AI in Wine Making

Entrepreneurs utilize artificial intelligence to analyze chemical attributes and consumer preferences to predict wine purchases.
Last year, approximately 126,000 unique wine labels were applied for by wineries, highlighting market saturation.
Katerina Axelsson founded Tastry to enhance wine selection using chemistry, consumer feedback, and AI.

The Role of Chemistry in Wine

Human perception of wine is influenced by the context of flavor compounds, while machines process data straightforwardly.
A single compound like benzaldehyde can be perceived differently based on surrounding flavors, making wine tasting complex.
Winemakers traditionally rely on intuition and experience in blending wines, impacting the multibillion-dollar industry.

AI Training and Functionality

Tastry's AI model analyzes the chemical compositions of numerous wines combined with sensory data from tasting panels.
The technology aims to replicate human-like tasting abilities, improving wine quality and blend recommendations.
Winemakers now use Tastry's platform for marketing insights, identifying regional trends and tailoring products to diverse palates.

Marketing's Impact on Wine Preference

Marketing plays a significant role in shaping consumer preferences, often more than the actual taste.
For instance, perceptions of Kim Crawford's sauvignon blanc among women aged 20-40 are more about effective marketing than flavor appeal.

Grape Ripening Insights

Unlike some fruits, grapes do not ripen post-harvest; thus, timing for grape picking is crucial.
Researchers at the University of Montpellier have studied ripening variances within grape clusters using single-berry metabolomics.
Findings indicate each grape may have different ripening timelines due to individual metabolic processes.

Technological Advancements in Harvesting

AI-powered machines enable selective grape sorting based on individual ripeness levels, aiding winemakers in achieving optimal harvests.

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Description

Explore the fascinating world of viruses and prions in Chapter 5. Learn about their discovery, evolution, and impact on various organisms. This quiz will test your understanding of these infectious agents and their significance in biology.