Visualizing Human Bio Ch 11

What are bacteria?

Ubiquitous microscopic organisms that may have been the first life forms on Earth.

What role do bacteria play in the ecosystem?

They help maintain the nutrient cycles that keep plants and animals alive.

What percentage of bacterial species are pathogenic to humans?

Only 1% of total bacterial species are pathogenic.

What type of cells are bacteria classified as?

Bacteria are prokaryotes that lack a nucleus.

What is the significance of cyanobacteria?

Cyanobacteria are photosynthesizing bacteria that produce a large amount of oxygen.

How do bacteria communicate with each other?

Bacteria use quorum sensing to influence their environment and communicate.

What is quorum sensing?

A process where bacteria sense their population density and make environmental changes accordingly.

What is an autoinducer?

A signaling protein produced by bacteria that initiates quorum sensing.

What happens when autoinducers are released into the environment?

They bind to bacterial cell receptors, triggering a positive feedback loop that increases autoinducer production.

What is the relationship between bacterial population and inducers?

As the bacterial population increases, the number of inducers, or 'chemical calling cards,' also increases.

Are inducers species-specific?

No, each bacterial species creates a generic inducer that can alert other bacterial species.

How do different bacterial species cooperate?

Many different species can cooperate to produce necessary enzymes and other compounds.

What is quorum sensing in bacteria?

A communication method used by bacteria for processes like biofilm formation, virulence, and antibiotic resistance.

What are biofilms?

Complex structures formed by colonies of bacteria and other microbes that adhere to surfaces and act as a single organism.

How do biofilms impact human health?

They can contain pathogenic bacteria and adhere to surgical instruments, flatware, and sinks, potentially leading to infections.

What is the process of protein production in bacteria during quorum sensing?

Bacteria produce identifying proteins that trigger species recognition, leading to gene activation and new protein production when a threshold cell count is reached.

What is the Human Microbiome Project?

A project initiated in 2008 to characterize and analyze the role of microbes in human health and disease.

How many bacterial cells do humans have compared to human cells?

Humans have approximately 45-60 trillion bacterial cells, which is more than the ~30 trillion human cells.

What is metagenomics?

The analysis of a mixed sample of microbiome DNA that contains DNA from every species of bacteria present.

What are the five areas of the human body that house different microbiomes?

Nasal passages, oral cavity, skin, gastrointestinal tract, and urogenital tract.

What are the aims of the Human Microbiome Project?

To develop a reference set of microbial genome sequences, identify microbiome communities, determine disease relationships, develop data analysis tools, and examine ethical aspects.

How do newborns acquire their microbiome?

Newborns pick up their bacterial microbiome from the mother during birth and through breastfeeding.

What benefits do microbiomes provide?

They can produce chemicals that prevent pathogen colonization, secrete toxins against specific microbes, alter pH, and compete for resources.

What is the significance of the laws of ecology in microbiome colonization?

Existing bacteria in a microbiome can affect the ability of new bacteria to colonize, as only one organism can occupy a niche.

What is the relationship between biofilm formation and pathogenic bacteria?

Pathogenic bacteria like streptococcus cannot cause disease at low numbers due to the metabolic cost of producing adherence and virulence factors.

What unique aspects influence the development of an infant's microbiome?

The infant's unique biochemistry enhances the growth of certain bacterial species, leading to a distinct microbiome even in controlled environments like NICUs.

What is the common core of microbes in the human microbiome?

A predictable set of microbes shared among humans, along with individual variations based on experiences and environment.

How do different microenvironments affect microbiome composition?

Each area of the body has overlapping but unique bacterial species due to varying conditions and resources.

What is the first goal of the Human Microbiome Project?

To characterize the typical microbiome found in and on the human body.

What are the two types of fungi and five protozoan species in the microbiome?

They are part of the resident flora that normally reside at specific sites without causing disease under normal conditions.

What is the human microbiome and how does it develop?

The human microbiome develops over a long period, with significant shifts in dominant species occurring during the first 2-3 years of life.

What role do gut microbiomes play in the human body?

Gut microbiomes protect the gut lining from infections, aid in digestion, and produce B vitamins, Vitamin K, folate, and short-chain fatty acids.

How do gut microbiomes interact with the immune system?

The immune system and gut microbiome are separated by the intestinal lining; Antigen Presenting Cells allow gut microbiomes to flourish while protecting against infections.

What happens to immune cell function in the absence of gut microbiomes?

Without gut microbiomes, neutrophil counts remain low during infections, and Natural Killer Cells cannot function correctly.

What health issues are linked to abnormal gut microbiomes?

Altered gut bacteria proportions are correlated with diabetes, obesity, and cancer.

What is microbial dysbiosis?

Microbial dysbiosis refers to imbalances in bacterial populations that can be linked to various diseases, including tooth decay and depression.

How does diet influence the gut microbiome?

Diet plays a significant role in shaping the proportions of different bacteria in the gut microbiome.

What are probiotics?

Probiotics are compounds that stimulate the growth of beneficial microorganisms and often contain live bacteria that survive stomach acid.

What are prebiotics?

Prebiotics are non-digestible carbohydrates that serve as food for healthy bacteria in the gut.

How can microbiomes be used in forensic science?

The Human Microbiome Project is being investigated for its potential use in forensic investigations, as individual microbiomes can serve as identification markers.

What is the significance of antibiotic resistance in gut microbiomes?

Gut microbiomes can harbor antibiotic-resistant bacteria, which is important for tracking bacterial adaptation to antibiotics.

What ethical concerns are associated with the Human Microbiome Project?

The Human Microbiome Project raises ethical concerns similar to those of the Human Genome Project.

What is the connection between gut microbiome and brain function?

Recent studies indicate a connection between gut microbiomes and brain malfunctions.

How do microbiomes differ among individuals?

Individual microbiomes can vary at both species and subspecies levels, even among identical twins.

What is the role of gut microbiomes in reproductive health?

Understanding microbiomes has contributed to advancements in reproductive health.

What are some diseases linked to gut microbiome imbalances?

Diseases linked to gut microbiome imbalances include Celiac disease and irritable bowel syndrome.

What is the relationship between Firmicutes and Bacteroidetes in obesity?

Obese individuals tend to have a higher percentage of Firmicutes, while thinner individuals have a higher percentage of Bacteroidetes.

What is the purpose of taking probiotics after antibiotics?

Taking probiotics after antibiotics is recommended to replenish beneficial bacteria that may have been destroyed.

How can microbiome profiling be used for identification?

Profiling the skin microbiome could serve as an identification marker, similar to DNA or fingerprints.