Prokaryotic and Eukaryotic Cells Quiz

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Questions and Answers

What is the size range of most clinically relevant bacterial species?

0.05 to 0.5 µm in width and 0.5 to 1 µm in length

0.25 to 1 µm in width and 1 to 3 µm in length (correct)

0.5 to 5 µm in width and 5 to 10 µm in length

1 to 10 µm in width and 10 to 30 µm in length

Which characteristic distinguishes prokaryotic cells from eukaryotic cells?

Absence of cell walls

Presence of a defined nucleus

Presence of plasmids (correct)

Lack of nucleic acids

What is the significance of the differences in bacterial cell walls?

They determine the replication rate of bacteria

They influence resistance to antibiotics

They provide the basis for the Gram stain (correct)

They determine the metabolic rate of the bacteria

Which of the following options is incorrect about bacterial cells?

They contain organelles such as mitochondria. Signup and view all the answers

Which of the following components is NOT typically found in both prokaryotic and eukaryotic cells?

Cell walls Signup and view all the answers

Which substance primarily composes the granules that lessen osmotic pressure?

Polysaccharides Signup and view all the answers

What is the primary function of polyphosphate granules?

Storage of inorganic phosphates Signup and view all the answers

Which type of antibiotic interferes with protein synthesis by attaching to the 50S subunit?

Chloramphenicol Signup and view all the answers

What forms the primary genetic material in bacteria?

Circular chromosome Signup and view all the answers

What are gas vacuoles primarily associated with?

Buoyancy in water Signup and view all the answers

Which type of granules are also known as Babes-Ernst Bodies?

Volutin granules Signup and view all the answers

What is the function of glycogen in bacteria?

Energy storage Signup and view all the answers

Which of the following is present in the nucleoid of bacteria?

Chromatin body Signup and view all the answers

What is a unique characteristic of Mycoplasma regarding its membrane composition?

It incorporates sterols from its environment. Signup and view all the answers

Which of the following is NOT a function of bacterial membranes?

Storage of genetic information Signup and view all the answers

Which transport mechanism involves simultaneous transport of two substrates in the same direction?

Symport Signup and view all the answers

What is a primary advantage of aerobic organisms regarding ion-motive force?

They have easier time generating an ion-motive force. Signup and view all the answers

Which type of transport mechanism is characterized by the transport of two like-charged compounds in opposite directions?

Antiport Signup and view all the answers

What role do membranes play in electron transport for aerobic species?

They facilitate oxidative phosphorylation. Signup and view all the answers

Which statement about the housing of enzymes in bacterial membranes is true?

They are involved in outer membrane synthesis. Signup and view all the answers

In which type of transport does a substrate move independent of any coupled ion?

Uniport Signup and view all the answers

What microorganism is known for having a terminal spore?

Clostridium tetani Signup and view all the answers

Which property of endospores protects bacteria from human defense mechanisms?

The existence of a capsule that resists phagocytosis. Signup and view all the answers

Which type of bacteria is characterized by a subterminal spore location?

Clostridium botulinum Signup and view all the answers

What method can be used to detect somatic antigens after capsule removal?

Boiling a suspension of the microorganism. Signup and view all the answers

What is a characteristic of the spore protoplast found in endospores?

It contains a complete nucleus. Signup and view all the answers

In what way does the slime layer differ from a capsule?

The slime layer is loosely attached to the cell wall. Signup and view all the answers

Which characteristic is true about the capsule of some bacteria?

It can appear as a clear area when using common stains. Signup and view all the answers

What does the spore wall of an endospore contain that is crucial to its function?

Normal peptidoglycan that becomes the cell wall. Signup and view all the answers

What is the main feature that distinguishes spirochetes from other bacteria?

Unique structure and motility Signup and view all the answers

How do true motility and Brownian movement differ in bacteria?

True motility involves directed movement; Brownian movement is random. Signup and view all the answers

What structure allows bacteria to move by swimming in a definite direction?

Flagellum Signup and view all the answers

Which laboratory method is commonly used to observe true motility?

Hanging Drop Method Signup and view all the answers

In which type of bacteria would you expect to find two pairs of rings in the basal body of the flagellum?

Gram-negative bacteria Signup and view all the answers

What term describes the movement of bacteria toward or away from a stimulus?

Chemotaxis Signup and view all the answers

What is the primary function of pili (fimbriae) in bacteria?

Adhering to surfaces Signup and view all the answers

What best describes the term 'tumble' in relation to bacterial movement?

Sharp change in direction Signup and view all the answers

Which characteristic structure in bacteria forms a helix and is composed of flagellin?

Filament Signup and view all the answers

What factor contributes to the swarming behavior observed in Proteus bacteria?

Flagellar density Signup and view all the answers

Study Notes

Prokaryotic Vs. Eukaryotic Cells

Chemically similar - both contain nucleic acids, protein, lipids, and carbohydrates
Both have ribosomes, but prokaryotic ribosomes are smaller (70S) and eukaryotic ribosomes are larger (80S)
Prokaryotes lack membrane-bound organelles (e.g., mitochondria, Golgi apparatus, endoplasmic reticulum)
Prokaryotic genome consists of a single, circular chromosome, while eukaryotic genome is organized into multiple linear chromosomes within a nucleus
Prokaryotes divide by binary fission, while eukaryotes divide by mitosis or meiosis
Prokaryotic cell walls contain peptidoglycan, which is absent in eukaryotic cell walls

Bacterial Morphology

Bacteria vary in size, morphology, cell-to-cell arrangement, and chemical composition and structure of the cell wall
Bacterial cell wall differences form the basis for the Gram stain
Most clinically relevant bacterial species range in size from 0.25 t0 1um in width and 1 to 3um in length
Bacteria are 100 times larger than a virus and 10 times smaller than a eukaryotic cell

Bacterial Structures

Cell wall: provides structural support and shape, and protects the cell from osmotic lysis. Composed of peptidoglycan.
Plasma membrane: regulates the transport of nutrients and waste products. Composed of phospholipids and proteins.
Cytoplasm: the gel-like substance within the cell membrane that contains the cell's genetic material, ribosomes, and other essential components.
Ribosomes: responsible for protein synthesis.
Nucleoid: the region of the cytoplasm where the bacterial chromosome is located. Not enclosed by a membrane.
Flagella: long, whip-like appendages that allow bacteria to move.
Pili (fimbriae): short, hair-like structures that help bacteria adhere to surfaces.
Capsule: a gelatinous layer that surrounds some bacteria, protecting them from phagocytosis by white blood cells.
Spores: dormant, highly resistant forms of bacteria that can survive harsh conditions.

Endospores

Responsible for perpetuation
Not involved in multiplication
Examples: Bacillus, Clostridium
Types of spores based on location:
- Terminal spore (Clostridium tetani)
- Subterminal spore (Clostridium botulinum)
- Central spore (Bacillus anthracis)
Properties of Endospores:
- Core: spore protoplast, containing a complete chromosome, protein-synthesizing apparatus, and a glycolysis-based energy-generating system.
- Spore wall: the innermost layer surrounding the inner spore membrane, composed of peptidoglycan.
- Exosporium: the outermost layer of the endospore, composed of protein.

Capsule

Composed of polysaccharide or polypeptide
Protects the bacteria from the attacks of the human defense system
Resists phagocytosis
Resists desiccation
Capsules sometimes must be removed for detecting the somatic (cell wall) antigens
Capsule removal achieved by boiling a suspension of the microorganism
Capsules do not stain with common laboratory stains (Gram or India ink)

Slime Layer

Unorganized material loosely attached to the cell wall
Diffuses between the cell wall and the surrounding medium

Spirochetes

A group of bacteria with unique structure and motility
Movement achieved by axial filaments or endoflagella
True motility and Brownian movement are best observed through the Hanging Drop Method
Flagellar staining, serological tests, fluorescent antibody techniques, and swarming phenomena can also be used to demonstrate motility

Taxis

Movement of bacteria toward or away from a particular stimulus
Types of Taxis:
- Chemotaxis - movement in response to chemical stimuli.
- Phototaxis - movement in response to light stimuli.
- Aerotaxis - movement in response to oxygen stimuli.
- Magnetotaxis - movement in response to magnetic stimuli.

Pili (Fimbriae)

Hairlike, proteinaceous structures extending from the cell membrane into the external environment
Approximately 2 μm long
Hair-like microfibrils usually produced by flagellated Gram-negative bacteria.
Observable by electron microscopy
Assist with attachment to surfaces.

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Description

Test your understanding of the differences between prokaryotic and eukaryotic cells, including their structures, functions, and reproduction methods. This quiz will also cover bacterial morphology and how it relates to classification, such as the Gram stain technique. Dive into the fascinating world of cellular biology!