Bacterial Structure & Metabolism

What is the typical size range for a prokaryotic cell?

1-3 μm

What is the typical size range for a eukaryotic cell?

5-10 μm

Which specific genus of bacteria is the exception to the rule that all bacteria possess a cell wall?

Mycoplasma

How does the cytoplasmic membrane of a eukaryote differ from that of a prokaryote regarding lipid composition?

Eukaryotic membranes contain sterols, while prokaryotic membranes do not.

In which cell type is a nuclear membrane present?

Eukaryote

True or False: A nucleolus is a structure found within prokaryotic cells.

FALSE

Describe the organization of DNA in a prokaryotic cell.

It is a single DNA molecule with no associated proteins.

What protein is associated with DNA in eukaryotic chromosomes?

Histones

Where is the site of respiration in a prokaryotic cell?

The cytoplasmic membrane

In eukaryotes, respiration is associated with which organelle?

Mitochondrion

What is the primary method of reproduction for prokaryotes?

Asexual (binary fission)

Microscopic, single-celled organisms with no organized nucleus are classified as _____.

Bacteria

Which group of microbes is defined as acellular and consisting of DNA or RNA?

Viruses

Concept: Fungi

Definition: Uni/multicellular heterotrophic eukaryotes that obtain nutrients through absorption.

What are the seven major levels of bacterial taxonomy, starting from the broadest level (excluding Domain)?

Kingdom, Phylum, Class, Order, Family, Genus, and Species.

What is the eighth taxonomic level sometimes used above the level of Kingdom?

Domain

How do capsules function as a virulence factor for bacteria?

They protect the organism from destruction by the host.

What physical characteristic do encapsulated bacteria produce on agar plates?

Sticky or slimy colonies

What laboratory step is required to determine the serogroups of encapsulated Shigella or Salmonella?

Boiling the sample

What is the primary function of pili regarding genetic material?

Connecting two bacterial cells to exchange DNA.

How does the presence of pili (acting as an "adhesin") affect bacterial colonization?

It facilitates adherence to cell surfaces, increasing colonizing ability.

How do pili affect the likelihood of bacterial phagocytosis?

They decrease the chance of phagocytosis.

What is the primary function of bacterial flagella?

Motility (movement)

Name the bacterial structure shown as small hair-like appendages used for attachment in [SOURCE_IMAGE_3].

Fimbriae

Which bacterial structure is designed for long-term survival under harsh conditions?

Endospores

The process where a bacterium takes up plasmid DNA from its environment is called _____.

Transformation

Define the mechanism of Transduction in bacterial genetics.

The injection of viral DNA into a bacterial cell.

In Conjugation, what is the name of the donor cell that provides DNA to the recipient?

The F+ cell

In Conjugation, what is the name of the recipient cell that receives DNA?

The F- cell

What is the typical range for bacterial generation (doubling) time?

20 minutes to 2 hours

On a bacterial growth curve, what is the initial phase where numbers remain constant as cells adapt?

Lag phase

Which phase of the growth curve is characterized by rapid, constant cell division?

Log (or exponential) growth phase

What occurs during the stationary phase of the bacterial growth curve?

The rate of cell growth equals the rate of cell death, resulting in a plateau.

The final stage of the growth curve where the population size decreases is the _____.

Death (or logarithmic decline) phase

What is the preferred starting carbohydrate for most bacterial metabolic pathways?

Glucose

In bacterial oxidation (respiration), what serves as the final electron acceptor?

Molecular oxygen (O2)

Is fermentation an aerobic or anaerobic process?

Anaerobic

Name four common end products of bacterial fermentation.

Lactate, butyrate, ethanol, and acetoin.

Which metabolic pathway is used by most bacteria, especially the Enterobacteriaceae?

Embden-Meyerhof Pathway (EMP)

Lactobacillus and B. abortus utilize which pathway to metabolize glucose into pyruvic acid?

Pentose phosphate pathway

The Entner-Doudoroff pathway is an aerobic process used by which genus of bacteria?

Pseudomonas

What is the common end product of the three major glucose metabolism pathways in bacteria?

Pyruvate (or pyruvic acid)

In what way is understanding bacterial weapons like antibiotic resistance important for medical treatment?

It helps clinicians "know their enemy" to better combat infections.

How can bacterial structural differences be exploited in laboratory medicine?

As targets for detection and identification techniques.

Why are bacterial structures considered "targets" in vaccine development?

They serve as the basis for antibody production.

What defines a "True nucleus" in eukaryotic cells?

A nucleus bound by a nuclear membrane.

Identify the genetic transfer mechanism illustrated in panel B of [SOURCE_IMAGE_5].

Transduction

Identify the genetic transfer mechanism illustrated in panel A of [SOURCE_IMAGE_5].

Transformation

Identify the genetic transfer mechanism illustrated in panel C of [SOURCE_IMAGE_5].

Conjugation

Concept: Generation Time

Definition: The time it takes for a bacterial population to double in number through binary fission.

Which bacterial appendage is specifically described as facilitating the exchange of DNA between cells?

Sex pilus (or Pili)

In the bacterial growth curve, the Y-axis represents the _____.

Log of numbers of bacteria

In the context of bacterial identification, what is the significance of fermentation end products?

They are used in biochemical identification (ID) tests.

According to the presentation, what is the end product of the Kreb's Cycle (aerobic use of pyruvate)?

CO2 and H2O (implied by respiration/metabolism outcomes).

Which category of microorganisms obtains nourishment directly from a host?

Parasites

Which eukaryotic microbes are described as unicellular or multicellular heterotrophs?

Fungi

In the taxonomic hierarchy, what level follows 'Order' and precedes 'Genus'?

Family

True or False: Most bacteria prefer to metabolize complex carbohydrates before attempting to use glucose.

False (Bacteria always want glucose first).

What external bacterial structure is shown as a thick outer coating in [SOURCE_IMAGE_3]?

Capsule

According to the image [SOURCE_IMAGE_4], endospores typically appear as distinct shapes within or outside of _____ cells.

Bacillus (rod-shaped bacterial)