Prokaryotic Cells and Viruses: Structure, Replication, and Comparison

What is the function of the capsule in prokaryotic cells?

Prevents desiccation and protects the cell from antibiotics and viruses.

What is the size of prokaryotic ribosomes compared to eukaryotic ribosomes?

Prokaryotic ribosomes are smaller (70s) than eukaryotic ribosomes (80s).

How is the DNA organized in prokaryotic cells?

In a single circular loop not associated with proteins, meaning it doesn't form chromosomes.

What is a plasmid?

Small loops of DNA that can be shared between cells, usually containing useful genes like antibiotic resistance.

What is the composition of the cell wall in prokaryotic cells?

Made of murein, which is a mix of polysaccharides and peptides, different from plant and fungal cell walls.

What is the function of the flagellum in prokaryotic cells?

Used for locomotion.

What is the purpose of membrane infoldings (mesosomes) in prokaryotic cells?

To increase surface area for respiration or photosynthesis.

What are the steps of binary fission in prokaryotes?

1. DNA and plasmids replicate. 2. Cell elongates and DNA moves to opposite poles. 3. Cytoplasm begins to divide and new cell walls form. 4. Cytoplasm divides to produce two daughter cells.

What is the main difference between prokaryotic and eukaryotic cells?

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have them.

What are viruses classified as?

Neither prokaryotic nor eukaryotic; they are acellular non-living particles.

How much smaller are viruses compared to bacteria?

Viruses are 1000 times smaller than bacteria.

What do viruses consist of?

Genetic material (RNA or DNA) protected by a protein coat called the capsid, and may have a lipid envelope.

What is the role of attachment proteins in viruses?

They help viruses recognize and attach to a host cell.

What are the steps involved in virus replication?

1. Virus detects host cell and attaches. 2. Virus injects genetic material. 3. Host cell reproduces genetic material and creates new viral proteins. 4. Virus leaves the cell using part of the cell's membrane.

What is the function of the cell wall in prokaryotic cells?

Provides structural support and protection.

What is the difference in DNA structure between prokaryotic cells and eukaryotic cells?

Prokaryotic cells have circular DNA, while eukaryotic cells have linear DNA organized into chromosomes.

What is chitin?

A component of the cell wall in fungi, different from cellulose found in plant cell walls.

Why do prokaryotes undergo binary fission?

To reproduce asexually and rapidly increase their population.

What is the significance of ribosomes in prokaryotic cells?

They are the site of protein synthesis.

What is the difference between the cell walls of prokaryotes and eukaryotes?

Prokaryotic cell walls are made of murein, while eukaryotic plant cell walls are made of cellulose and fungal cell walls are made of chitin.

What is the function of the slime capsule in bacteria?

To protect against desiccation and immune responses.

What is the role of the mesosome in prokaryotic cells?

It increases the surface area for cellular processes like respiration.

What are the two types of genetic material found in viruses?

RNA and DNA.

What is the structure that contains the genetic material in a virus?

A strand of genetic material (either DNA or RNA)

What is the protective protein coat of a virus called?

Capsid

What type of cells do not contain a nucleus?

Prokaryotic cells

What are the smaller circular pieces of DNA found in prokaryotes called?

Plasmids

What is the main difference between eukaryotic and prokaryotic cells?

Eukaryotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells do not.

What type of cell wall do bacteria have?

Murein (peptidoglycan) cell wall

What are the hair-like structures that help bacteria move called?

Flagella

What is the term for organisms that are not considered living and are acellular?

Viruses

What is the function of attachment proteins in viruses?

They allow the virus to bind to a target cell.

How do viruses replicate within a host cell?

They inject their genetic material into the cell, tricking it into synthesizing new viruses.

What is the size comparison between prokaryotic and eukaryotic cells?

Prokaryotic cells are about 100 to 10,000 times smaller than eukaryotic cells.

What is the nuclear envelope?

The membrane that surrounds the nucleus in eukaryotic cells.

What are the main components of a virus?

Genetic material, capsid, and attachment proteins.

What do prokaryotic cells lack that eukaryotic cells possess?

Membrane-bound organelles.

What is the role of the cell wall in prokaryotes?

To protect the cell from desiccation or chemical attack.

What is the difference between DNA and RNA nucleotides?

1. DNA contains deoxyribose sugar, while RNA contains ribose sugar. 2. DNA is double-stranded, while RNA is usually single-stranded.

What is the function of ribosomes in cells?

To synthesize proteins.

What type of cells are chloroplasts found in?

Plant cells (eukaryotic cells).

What is the purpose of the Golgi body in eukaryotic cells?

To modify, sort, and package proteins and lipids for secretion or delivery to other organelles.

What is the significance of the endoplasmic reticulum (ER)?

It is involved in the synthesis of proteins (RER) and lipids (SER).

What is the primary function of mitochondria?

To produce energy (ATP) through cellular respiration.

What distinguishes viruses from living organisms?

Viruses do not perform life processes independently and require a host cell to replicate.

What is the role of the capsule in bacteria?

To protect the bacteria from desiccation and immune responses.

What are the two main types of cells based on the presence of a nucleus?

Eukaryotic cells (with a nucleus) and prokaryotic cells (without a nucleus).

What is the function of the cytoplasm in a cell?

To provide a medium for biochemical reactions and house organelles.

What is the significance of the relative size of ribosomes in prokaryotic cells?

Prokaryotic ribosomes are smaller than those in eukaryotic cells.

What are the main structures of eukaryotic cells?

Nucleus, cell-surface membrane, mitochondria, Golgi apparatus, smooth endoplasmic reticulum, rough endoplasmic reticulum, ribosomes, chloroplasts (in plants and algae), cell wall (in plants, algae, and fungi), and cell vacuole (in plants).

What is the structure of the nucleus?

Surrounded by a double membrane (nuclear envelope), contains chromosomes (protein-bound linear DNA), nucleoplasm, and one or more nucleoli.

What is the function of the nucleolus?

Produces ribosomes.

Describe the structure of the rough endoplasmic reticulum (RER).

A system of fluid-filled membranes studded with ribosomes, continuous with the nuclear membrane, and has a large surface area formed by folding.

What is the function of the smooth endoplasmic reticulum (SER)?

Synthesizes, stores, and transports lipids and carbohydrates.

What is the function of ribosomes?

Protein synthesis.

What is a prokaryote?

A single-celled organism without a nucleus and membrane-bound organelles, such as bacteria.

What is a eukaryote?

An organism with cells that have membranes around their complex organelles, often part of multicellular organisms.

What is the size range of prokaryotic cells?

Less than 1-2 µm in diameter.

What is the size range of eukaryotic cells?

10-100 µm in diameter.

What type of DNA do prokaryotes have?

Circular DNA.

What type of DNA do eukaryotes have?

Linear DNA.

Do prokaryotic cells have membrane-bound organelles?

No.

Do eukaryotic cells have membrane-bound organelles?

Yes.

What is the ribosome size in prokaryotic cells?

70S.

What is the ribosome size in eukaryotic cells?

80S.

What is the composition of the cell wall in prokaryotes?

Made of peptidoglycan (murein), a polysaccharide and peptide mix.

What is the composition of the cell wall in plant cells?

Cellulose.

What is the function of flagella in prokaryotic cells?

Used for locomotion.

What is binary fission?

The process by which prokaryotic cells replicate, involving DNA and plasmid replication, cell elongation, and division.

What is the theory of endosymbiosis?

A theory that explains the origin of eukaryotic cells from prokaryotic organisms.

What are viruses?

Acellular non-living particles that require a living cell to reproduce and consist of genetic material protected by a protein coat.

What is the size comparison between viruses and bacteria?

Viruses are 1000x smaller than bacteria.

What is the first step in viral replication?

Virus detects host cell by recognizing protein markers on its membrane.

What happens after a virus attaches to a host cell?

The virus injects its genetic material into the cell.

How does a virus reproduce within a host cell?

The host cell reproduces the viral genetic material and creates new viral proteins.

What happens when a virus leaves a host cell?

It uses some of the host cell's own membrane to form itself.