Bio Chapter 19, 26, ect.

Exam 1

Viral Envelope

Outer layer with glycoproteins that surrounds the viruses capsid

Virus That Infects Only Bacteria

Bacteriophages or just phages

Virulent Phage

A phage that only reproduces by the lytic cycle

Restriction Enzymes

Cellular enzymes that restrict a phages ability to reproduce by cutting them up after they’re identified

The Protein Shell of A Virus

Capsid (Made from protein subunits called capsomeres)

Temperate Phages

Phages that do both the lytic cycle and the lysogenic cycle

Viral Genome

Single or double, DNA or RNA

Viruses are not considered alive because…

1. They are not made up of cells

2. Do not breathe

3. Require host cell to reproduce

4. Do not release or produce waste

5. Do not store or obtain energy

Viruses are considered alive because…

1. Can reproduce

2. Can move

3. Can respond to stimuli

4. Has genes and DNA/RNA

What is it called when retrovirus viral DNA integrates with host genome?

Provirus (remains a permanent resident)

Retroviruses

Uses the enzyme reverse transcriptase (RNA to DNA)

Exocytosis

A cellular process where cells transport molecules from their interior to the exterior. This occurs when membrane-bound vesicles, containing substances like proteins, hormones, neurotransmitters, or waste products (including toxins), fuse with the plasma membrane and release their contents outside the cell. It is an energy-dependent process crucial for secretion, cell communication, and waste removal.

Process of Phage Replication (RTTS)

1. Replicated by host enzymes

2. Transcribed by host enzymes

3. Translated by host ribosomes

4. Self-assembled with viral genome

What are the contents of a virus?

Capsid protein covering, DNA/RNA, and sometimes a membranous envelope

Lysogenic

Phages coexist with the host cell while reproducing

Lysosomes

Destroys bad things in the cell through enzymes

Vaccine

A harmless version of pathogenic microbes that stimulates the immune system

Emerging Viruses

Viruses that suddenly become apparent

What are three ways viruses emerge?

1. High mutation rates because they don’t have double checking

2. From a small isolated population to a large population

3. Jumping species through mutation

What are the two ways plant viruses enter?

1. Horizontal transmission

2. Vertical Transmission

Horizontal Transmission

Entering through damaged cell walls

Vertical Transmission

Passed down from a plant parent

Prion

incorrectly misfolded, practically indestructible protein that persuades other proteins to fold the wrong way

Aggregates of Prions

a group or complex of prions

Polymerases

Enzymes that make DNA/RNA

Host Range

The list of types of cells that a virus can infect.

How does a virus identify different types of cells?

It does this by using viral surface proteins and the host cell’s receptor molecules

Lytic Cycle

Virus reproductive cycle ends in cell death. It involves the phage directing the host cell to make an enzyme that damages the cell wall. This makes the cell swell and eventually explode.

What is it called when a viral genome integrates with bacterial genomes?

Prophage

Viroid

Circular RNA nucleic acids with no protein shell that act as a virus in plants