Learn: lect #9

What is the 1 step growth curve for phages (viruses)?

A growth curve showing the number of phages over time as phages infect a host, produce new viral components, and eventually release new viruses.

What does the y-axis show on the 1 step growth curve for phages?

The number of phages.

What does the x-axis show on the 1 step growth curve for phages?

Time (min).

What are the two main parts shown on the phage growth curve?

The latent period and the burst phase.

What happens during the latent phase of the 1 step growth curve for phages?

No phages are detected.

Why is there a latent phase in the 1 step growth curve for phages?

No viruses are present because the virus DNA has been injected into the host and the host synthesizes viral components.

What is happening to the virus during the latent phase even though no phages are detected?

The virus DNA has been injected into the host, and the host synthesizes viral components.

What happens at the burst phase?

New viruses are being made and are suddenly released at the burst phase.

What is happening to the number of phages at the burst phase?

The number of phages suddenly increases as new viruses are released.

What is a virus?

DNA or RNA with information to tell the cell how to make 1 protein.

What are nucleic acids in a virus?

Nucleic acids (DNA/RNA) are informational.

What are proteins?

Proteins are worker molecules.

What is the central dogma of molecular biology?

DNA → RNA → Protein.

What process goes from DNA to RNA?

Transcription.

What process goes from RNA to protein?

Translation.

What happens to mRNA?

mRNA exits through ribosomes in the cytoplasm, so proteins can be made.

Why is mRNA a critical molecule?

mRNA is a critical molecule for making proteins.

How is the information on mRNA defined?

The info on mRNA is defined as positive info — the info that is necessary to make protein.

What happens when a nucleic acid is being made?

Another strand of nucleic acid is used as a template and the new strand is complementary to the template.

What is the relationship between the new nucleic acid strand and the template?

The new strand is complementary to the template.

If mRNA is positive information, what must the strand of DNA used to make mRNA be?

The strand of DNA used to make mRNA must be negative.

Why must the DNA strand used to make mRNA be negative?

Because the information on mRNA is positive information, and the strand used as the template is complementary to it.

What are some differences among animal viruses?

Some have DNA or RNA; some have double-stranded DNA (ds); some have single-stranded DNA (ss).

What types of DNA can animal viruses have?

Some have double-stranded DNA (ds), and some have single-stranded DNA (ss).

What types of RNA can animal viruses have?

Some have double-stranded RNA and some have single-stranded RNA.