BIOLD 251 Final Meow

Viruses

Submicroscopic infectious agents requiring host cells.

Plasmids

Small DNA molecules independent of chromosomal DNA.

Horizontal gene transfer

Transfer of genetic material between organisms.

Prokaryotic cells

Cells without a nucleus, like bacteria.

Eukaryotic cells

Cells with a nucleus, including human cells.

Gram stain

Laboratory technique to classify bacteria by cell wall.

Enveloped viruses

Viruses with a lipid membrane surrounding them.

Non-enveloped viruses

Viruses lacking a lipid membrane, more resistant.

Bacteria size

Typically 0.5 to 5 micrometers in diameter.

Virus size

Generally 20 to 300 nanometers in diameter.

Immune response to bacteria

Can lead to harmful effects if indiscriminate.

Viruses are diverse in structure but typically consist of

Nucleic acid: DNA or RNA, single-stranded or double-stranded.

Capsid: A protein coat that protects the genetic material.

Envelope: Some viruses have an outer lipid envelope derived from the host cell membrane.

Nucleic acid

DNA or RNA, single-stranded or double-stranded.

Capsid

A protein coat that protects the genetic material.

Structures of Plasmids

Are small, circular DNA molecules found in bacteria. They replicate independently of the bacterial chromosome and often carry genes for antibiotic resistance or other traits.

Healthcare Worker's Concern about Horizontal Gene Transfer

Because it can spread antibiotic-resistance genes between bacteria, this can lead to the emergence of multi-drug resistant bacteria, making infections more difficult to treat.

Replication Steps (General)

The specific replication steps vary depending on the organism, but generally involve:

Initiation: The replication process starts.

Elongation: New DNA or RNA strands are synthesized.

Termination: The replication process ends.

Prokaryotic

Simple cells lacking a nucleus and membrane-bound organelles.

Eukaryotic

Complex cells with a nucleus and membrane-bound organelles.

Size Difference Between Bacteria and Viruses

Bacteria are significantly larger than viruses. Bacteria are typically measured in micrometers (µm), while viruses are measured in nanometers (nm).

Gram Stain

is a technique used to classify bacteria into two groups based on their cell wall structure: Gram-positive and Gram-negative.

Enveloped vs. Non-Enveloped Microbe

Enveloped: Microbes with a lipid envelope derived from the host cell membrane.

Non-enveloped: Microbes without a lipid envelope.

Enveloped

Microbes with a lipid envelope derived from the host cell membrane.

Non-enveloped

Microbes without a lipid envelope.

Immune System Targeting All Bacteria

If the immune system targets all bacteria, it can lead to sepsis, a life-threatening condition caused by the body's overwhelming response to infection.

This can damage organs and lead to multiple organ failure.