Bio 139 exam 1

lThe main structures of flagella

basal body, hook, and filament.

exosporium

is an outermost layer made of protein and carbohydrate.

germ theory of disease

is the idea that diseases are caused by microorganisms. The germ theory of disease is widely accepted today and has led to significant advancements in medicine and public health.

Core contains

the bacterial chromosome and is surrounded by a thick cortex

The main components of an endospore include

the core, cortex, spore coat, and exosporium.

Planktonic bacteria

Bacteria found as free moving single cells.

Cell wall composition:

Bacterial cell walls are made of peptidoglycan, a complex molecule composed of sugars and amino acids, while archaeal cell walls are composed of other materials such as pseudopeptidoglycan or S-layer proteins.

Bacterial endospores and fungal spores

Bacterial endospores and fungal spores are both structures used by microorganisms to survive unfavorable environmental conditions.

Differences between Archaea and Bacteria in the Cellular structures and corresponding function.

Cell wall composition: Bacterial cell walls are made of peptidoglycan, a complex molecule composed of sugars and amino acids, while archaeal cell walls are composed of other materials such as pseudopeptidoglycan or S-layer proteins. Membrane lipids: Bacterial membrane lipids are composed of fatty acids linked to glycerol, while archaeal membrane lipids are composed of isoprenoid chains linked to glycerol, which can form ether bonds instead of ester bonds. This makes archaeal membranes more stable in extreme environments. Ribosomes: Archaeal and bacterial ribosomes differ in their size, structure, and composition of RNA and proteins. Archaeal ribosomes are more similar to eukaryotic ribosomes than bacterial ribosomes.

Compare and Contrast the cellular envelope of G+ and G- bacteria

Cell wall: G+ bacteria have a thick peptidoglycan layer in their cell walls, which retains the crystal violet stain in the Gram stain test, giving them a purple color. G- bacteria have a thinner peptidoglycan layer surrounded by an outer membrane, which does not retain the crystal violet stain and is instead stained pink by the counterstain in the Gram stain test. Outer membrane: G- bacteria have an outer membrane that contains lipopolysaccharides, porins, and other proteins. The outer membrane acts as a protective barrier against environmental stressors such as antibiotics, detergents, and host immune defenses. G+ bacteria lack an outer membrane and have a thick peptidoglycan layer that provides structural support and protection. Periplasmic space: G- bacteria have a periplasmic space between the inner and outer membranes, which contains various enzymes, transport proteins, and other molecules involved in nutrient uptake, signaling, and defense. G+ bacteria have a smaller periplasmic space or lack one altogether. Cell membrane: Both G+ and G- bacteria have a phospholipid bilayer cell membrane that regulates the exchange of molecules between the cell and its environment, maintains the electrochemical gradient, and plays a role in signal transduction and energy metabolism.

Sergei Winogradsky (1856-1953)

Russian Bacteriologist - worked primarily on Soil BacteriaDiscovered Chemolithotrophic bacteria obtain energy from inorganic compounds fix Carbon entirely from CO2 No Photosynthesis

The taxonomic categories, from the highest level to the lowest, are:

The taxonomic categories, from the highest level to the lowest, are: Domain Kingdom Phylum (or Division for some groups) Class Order Family Genus Species

Compound light microscope:

This type of microscope uses visible light and a series of lenses to magnify a specimen.

Endospores

are formed by some Gram-positive bacteria such as Bacillus and Clostridium.

To "kill" a bacterial endospore,

extreme heat or high-pressure sterilization is required.

The spore coat

protein layer that provides additional protection,

Confocal microscope:

uses a laser to illuminate a sample at a specific focal point, which is then detected by a detector. This allows for 3D imaging of samples at high resolution, and is commonly used in biological research, such as to visualize cellular structures in living tissue.

spontaneous generation

was an outdated idea that living organisms could arise from non-living matter,

Cell membrane:

Both G+ and G- bacteria have a phospholipid bilayer cell membrane that regulates the exchange of molecules between the cell and its environment, maintains the electrochemical gradient, and plays a role in signal transduction and energy metabolism.

In E. coli, CCW rotation causes

CCW rotation causes forward swimming, \

Basics of Compound light, Inverted, Fluorescence, Confocal, Transmission E/M and Scanning E/M (E/M = Electron Microscope). Be able to detail an experiment in which you might use one over another and why.

Compound light microscope: Inverted microscope: Fluorescence microscope: Confocal microscope: Transmission electron microscope Scanning electron microscope (SEM):

Robert Koch (1843-1910) fig 1.28

German Scientist, contemporary of Pasteur.Proved Germ Theory of Disease using Koch's Postulates (Review these: found page 22, Fig 1.29) in 1882using Mycobacterium tuberculosis and guinea pig proved M. tuberculosis caused TB/consumption:

Koch's Postulates

The bacteria must be present in all cases of the disease, and absent in healthy people/animals . The bacteria must be isolated from the sick host and grown in pure culture . The specific disease must be reproduced when a pure culture of the bacteria is inoculated into a healthy susceptible host. The bacteria must be recovered from the experimentally infected host, and shown to be the same as the original isolate.Isolated the bacteria in pure culture using "solid media" (at first was a potato, then media with gelatin, but with suggestion of Angelina Hesse, used agar agar (derived from seaweed) with beef broth as the growth media in a Petri dish.In 1905, Won the Nobel Prize for his discovery.

Bacteria

are single-celled prokaryotic organisms that are found in a wide range of habitats. They are diverse in shape and size, ranging from spherical (cocci) to rod-shaped (bacilli) to spiral-shaped (spirilla). Bacteria can be aerobic or anaerobic and can obtain energy through various means such as photosynthesis or by breaking down organic matter. They play important roles in various ecosystems, including decomposition, nitrogen fixation, and disease-causing infections in humans.

Periplasmic space:

between the cytoplasmic membrane and the outer membrane in Gram-negative bacteria, or between the cytoplasmic membrane and the peptidoglycan layer in Gram-positive bacteria. It contains various enzymes and transporters involved in nutrient acquisition and metabolism.

There are three different paradigms of flagellar movement:

clockwise (CW) rotation, counterclockwise (CCW) rotation, and reversible switching.

Ignaz Semmelweis (1818-1865)

introduced hand washing to prevent childbed fever

Miasmas,

or bad air, were thought to be the cause of many diseases.

viruses

- non-living entities that require a host cell to replicate and carry out their functions. They consist of a nucleic acid (either DNA or RNA) surrounded by a protein coat, and in some cases, an additional envelope derived from the host cell membrane. Viruses can infect a variety of organisms, including bacteria, plants, animals, and humans, and can cause a wide range of diseases, from the common cold to HIV/AIDS.

. In V. cholerae, the flagella rotate in a

. corkscrew-like fashion, allowing the bacteria to move forward.

Spirillum bacteria have flagella arranged in a tuft at one or both ends of the cell, allowing them

. to spin rapidly and move like a propeller.

Inverted microscope

: An inverted microscope is similar to a compound light microscope but has its light source and condenser located below the stage. This allows it to be used for examining samples in culture dishes or other containers. It is commonly used in cell culture research and other types of live cell imaging.

Outer membrane:

A layer found only in Gram-negative bacteria that is located outside the peptidoglycan layer. It contains lipopolysaccharides (LPS) and proteins, and serves as a barrier against certain molecules such as antibiotics and detergents. S-layer:

Capsule:\

A layer of polysaccharides that surrounds some bacterial cells, providing protection against host immune systems and allowing the bacteria to attach to surfaces.

Peptidoglycan

A rigid layer that surrounds the cell membrane of most bacteria. It is composed of repeating subunits of sugars and amino acids, and provides structural support for the cell.

Cytoplasmic Membrane:

A thin layer of lipids and proteins that surrounds the cytoplasm of prokaryotic and eukaryotic cells. Its main function is to regulate the movement of molecules in and out of the cell.

The taxonomic classification of Archaea and Bacteria is as follows:

Archaea: Domain: Archaea Kingdom: Archaea Bacteria: Domain: Bacteria Kingdom: Bacteria

Ribosomes:

Archaeal and bacterial ribosomes differ in their size, structure, and composition of RNA and proteins. Archaeal ribosomes are more similar to eukaryotic ribosomes than bacterial ribosomes.

Shapes of bacteria and how Gram Stain differentiates bacteria based on cellular structure.

Bacteria can have a variety of shapes, including spherical (coccus), rod-shaped (bacillus), spiral-shaped (spirillum), Cocci: Streptococcus ( Bacilli: Lactobacillus (rod-shaped). (spiral-shaped), The Gram stain is a laboratory technique that allows differentiation of bacterial cells based on their cell wall structure. The cell wall of bacteria can either be composed of a thick layer of peptidoglycan (Gram-positive) or a thin layer of peptidoglycan surrounded by an outer membrane (Gram-negative).

Examples of how bacteria are involved in production food & in Agriculture & their role on forest floor.

Bacteria play an important role in food production and agriculture, as well as in maintaining healthy ecosystems on the forest floor. Here are some examples: Food production: Bacteria are used in a variety of food production processes. For example, lactic acid bacteria are used to ferment milk into yogurt, cheese, and other dairy products. They are also used to ferment vegetables into pickles and sauerkraut. In addition, bacteria are used in the production of soy sauce, miso, and other fermented foods. Agriculture: Bacteria are used in agriculture in several ways. One example is the use of Rhizobium bacteria to fix nitrogen in the soil, which can reduce the need for synthetic fertilizers. Other bacteria, such as Bacillus thuringiensis, are used as a natural pesticide to control crop pests. Bacteria are also used in the production of biofertilizers, which can improve soil fertility and promote plant growth. Forest floor: Bacteria play an important role in the decomposition of organic matter on the forest floor. They break down dead plant material and animal remains, releasing nutrients back into the soil. This process is essential for maintaining healthy forest ecosystems.

There are three domains of life:

Bacteria, Archaea, and Eukarya. Archaea and Bacteria are both prokaryotic organisms, meaning they lack a distinct nucleus and membrane-bound organelles, while Eukarya are eukaryotic organisms, which possess a nucleus and other membrane-bound organelles.

Four types of microscopic organisms and their characteristics

Bacteria: Bacteria are single-celled prokaryotic organisms that are found in a wide range of habitats. They are diverse in shape and size, ranging from spherical (cocci) to rod-shaped (bacilli) to spiral-shaped (spirilla). Bacteria can be aerobic or anaerobic and can obtain energy through various means such as photosynthesis or by breaking down organic matter. They play important roles in various ecosystems, including decomposition, nitrogen fixation, and disease-causing infections in humans. viruses - non-living entities that require a host cell to replicate and carry out their functions. They consist of a nucleic acid (either DNA or RNA) surrounded by a protein coat, and in some cases, an additional envelope derived from the host cell membrane. Viruses can infect a variety of organisms, including bacteria, plants, animals, and humans, and can cause a wide range of diseases, from the common cold to HIV/AIDS. Fungi: Fungi are eukaryotic organisms that include yeasts, molds, and mushrooms. They are heterotrophic, meaning they obtain energy by breaking down organic matter. Fungi play important roles in nutrient cycling and decomposition in ecosystems. Some fungi also form mutualistic relationships with other organisms, such as mycorrhizal fungi that form symbiotic associations with plant roots. Protozoa: Protozoa are single-celled eukaryotic organisms that are found in aquatic and soil environments. They are diverse in shape and size, and can be free-living or parasitic. Protozoa can obtain energy through various means such as photosynthesis or by feeding on other organisms. Some protozoa play important roles in aquatic food webs, while others can cause diseases in humans and other animals.

Membrane lipids:

Bacterial membrane lipids are composed of fatty acids linked to glycerol, while archaeal membrane lipids are composed of isoprenoid chains linked to glycerol, which can form ether bonds instead of ester bonds. This makes archaeal membranes more stable in extreme environments.

The diseases caused by each of the endospore-forming anaerobic bacteria.

Clostridium botulinum: This bacterium produces botulinum toxin, which is one of the most potent toxins known. Botulinum toxin causes botulism, a rare but serious illness that can cause paralysis and even death. Botulism can be contracted by eating contaminated food or by coming into contact with contaminated soil. Clostridium tetani: This bacterium produces tetanus toxin, which can cause tetanus, also known as lockjaw. Tetanus is a serious bacterial infection that affects the nervous system and can cause muscle stiffness and spasms. Tetanus can be contracted through open wounds, especially puncture wounds. Clostridium perfringens: This bacterium can cause a variety of infections, including gas gangrene, which is a serious and potentially life-threatening condition that affects the skin, muscles, and other tissues. C. perfringens can also cause food poisoning, which is usually caused by eating contaminated meat, poultry, or other foods. Bacillus anthracis: This bacterium causes anthrax, a serious and potentially fatal disease that affects humans and animals. Anthrax can be contracted through contact with contaminated animals or animal products, such as wool or hides. These are just a few examples of the diseases that can be caused by endospore-forming anaerobic bacteria. It's important to note that not all species of these bacteria cause disease, and some species can even be beneficial to humans and animals.

Structure and Role/Function of the following: Cytoplasmic Membrane, Peptidoglycan, Outer membrane, S-layer, Capsule, Periplasmic space, LPS, Fimbrae/Pili, Cellular Inclusions (know all of the types we discussed), Gas Vesicles. What molecules make up some of these structures?

Cytoplasmic Peptidoglycan: Outer membrane: A layer found only in Gram-negative bacteria that is located outside the peptidoglycan layer. It contains lipopolysaccharides (LPS) and proteins, and serves as a barrier against certain molecules such as antibiotics and detergents. S-layer: A protein layer that is found in some bacteria and archaea, and is located outside the cell wall. It provides additional structural support and protection against environmental stresses. Capsule: A layer of polysaccharides that surrounds some bacterial cells, providing protection against host immune systems and allowing the bacteria to attach to surfaces. Periplasmic space: The space between the cytoplasmic membrane and the outer membrane in Gram-negative bacteria, or between the cytoplasmic membrane and the peptidoglycan layer in Gram-positive bacteria. It contains various enzymes and transporters involved in nutrient acquisition and metabolism. LPS: Lipopolysaccharides are molecules found in the outer membrane of Gram-negative bacteria. They consist of a lipid portion (lipid A) and a polysaccharide portion (O-antigen), and are involved in bacterial pathogenesis and immune evasion. Fimbrae/Pili: Hair-like appendages found on the surface of some bacteria, used for attachment to surfaces and other bacteria, and in some cases for the transfer of genetic material. Cellular Inclusions: Various types of structures found within bacterial cells that are used for storage of nutrients or other molecules. Examples include glycogen granules, polyphosphate granules, and gas vesicles. Gas Vesicles: Structures found in some aquatic bacteria that provide buoyancy and allow the bacteria to move up and down in the water column. They are composed of a protein shell and contain a gas, usually nitrogen or oxygen. The molecules that make up some of these structures include lipids and proteins in the cytoplasmic membrane, peptidoglycan subunits in the cell wall, lipopolysaccharides in the outer membrane, and polysaccharides in the capsule. Fimbrae and pili are composed of proteins, and gas vesicles are made of a protein shell. Cellular inclusions can contain a variety of molecules depending on their function.

Anton Leeuwenhoek (1632-1723)

Dutch Tailor, ground lenses as a "hobby"1684 Published findings of what he observed under the first microscope. (pg.Called them "Animalcules"

Endospores are a unique form of bacterial survival mechanism that can withstand harsh environmental conditions. They are highly resistant to heat, radiation, chemicals, and desiccation. Endospores are formed by some Gram-positive bacteria such as Bacillus and Clostridium. The main components of an endospore include the core, cortex, spore coat, and exosporium. The core contains the bacterial chromosome and is surrounded by a thick cortex layer made of peptidoglycan. The spore coat is a protein layer that provides additional protection, and the exosporium is an outermost layer made of protein and carbohydrate. Endospores are formed when environmental conditions become unfavorable for bacterial growth. The process of sporulation involves several stages, including DNA replication, asymmetric cell division, and formation of the cortex and spore coat. During sporulation, the bacteria produce specialized proteins called SASPs (small acid-soluble spore proteins) that help protect the DNA from damage. Dipicolinic acid and calcium ions also play an important role in endospore formation by stabilizing the spore structures. When conditions become favorable again, endospores can germinate and convert back to vegetative cells. This process involves the activation of enzymes that break down the spore coat and cortex, allowing the vegetative cell to emerge. To "kill" a bacterial endospore, extreme heat or high-pressure sterilization is required. Endospores can survive boiling, radiation, and most disinfectants. Examples of medically relevant bacteria that sporulate include Bacillus anthracis, which causes anthrax, and Clostridium tetani, which causes tetanus.

Endospores are a unique form of bacterial survival mechanism that can withstand harsh environmental conditions. They are highly resistant to heat, radiation, chemicals, and desiccation. Endospores are formed by some Gram-positive bacteria such as Bacillus and Clostridium. The main components of an endospore include the core, cortex, spore coat, and exosporium. The core contains the bacterial chromosome and is surrounded by a thick cortex layer made of peptidoglycan. The spore coat is a protein layer that provides additional protection, and the exosporium is an outermost layer made of protein and carbohydrate. Endospores are formed when environmental conditions become unfavorable for bacterial growth. The process of sporulation involves several stages, including DNA replication, asymmetric cell division, and formation of the cortex and spore coat. During sporulation, the bacteria produce specialized proteins called SASPs (small acid-soluble spore proteins) that help protect the DNA from damage. Dipicolinic acid and calcium ions also play an important role in endospore formation by stabilizing the spore structures. When conditions become favorable again, endospores can germinate and convert back to vegetative cells. This process involves the activation of enzymes that break down the spore coat and cortex, allowing the vegetative cell to emerge. To "kill" a bacterial endospore, extreme heat or high-pressure sterilization is required. Endospores can survive boiling, radiation, and most disinfectants. Examples of medically relevant bacteria that sporulate include Bacillus anthracis, which causes anthrax, and Clostridium tetani, which causes tetanus.

Motility & Chemotaxis Flagella: main structures of flagella (including Mot, and C, P, L rings), where energy for mvt. comes from. Location/name of different types of flagellated bacteria (e.g. Amphitrichous, Peritrichous, etc.), Three different paradigms of flagellar movement (e.g. CW vs CCW in E.coli, V. cholerae and a spirillum). The role of Chemotaxis. What does Chemotaxis mean? Swarming vs. Gliding motility and Brownian movement What are some names for different types of Chemotaxis. How does Phototaxis differ from Scotophobotaxis?

Flagella are long, whip-like appendages that bacteria use for motility. The main structures of flagella are the basal body, hook, and filament. The basal body consists of the Mot and C, P, L rings. The Mot protein acts as a rotor, powered by the proton motive force, while the rings anchor the flagellum to the cell wall and allow it to rotate. Different types of flagellated bacteria are named based on the number and location of flagella. For example, amphitrichous bacteria have one flagellum at each end of the cell, while peritrichous bacteria have multiple flagella distributed all over the cell surface. There are three different paradigms of flagellar movement: clockwise (CW) rotation, counterclockwise (CCW) rotation, and reversible switching. In E. coli, CCW rotation causes forward swimming, while CW rotation causes tumbling, which helps the cell change direction. In V. cholerae, the flagella rotate in a corkscrew-like fashion, allowing the bacteria to move forward. Spirillum bacteria have flagella arranged in a tuft at one or both ends of the cell, allowing them to spin rapidly and move like a propeller. Chemotaxis is the ability of bacteria to sense and move towards or away from chemical gradients in their environment. This is achieved through the use of chemoreceptors that bind to specific chemical signals and trigger changes in the direction of flagellar rotation. There are different types of chemotaxis, including aerotaxis (oxygen), phototaxis (light), thermotaxis (temperature), and osmotaxis (osmotic pressure). Swarming motility and gliding motility are two other types of bacterial movement. Swarming motility involves the coordinated movement of large groups of bacteria over a surface using flagella and extracellular slime. Gliding motility, on the other hand, does not involve flagella and is mediated by the secretion of a complex set of proteins and polysaccharides. Brownian movement is a random, erratic movement caused by the impact of molecules in the environment. It is not a form of directed motility. Phototaxis is the movement of bacteria towards or away from light, while scotophobotaxis is the movement towards or away from darkness. Regenerate response

Louis Pasteur (1822-1895)

French Chemist, hired to resolve issue of spoiled wine at a winery.Found two sizes of cells growing in the spoiled wine, only one size in the good wine.Through controlled experiments, (Scientific Method!) kept excellent notes, repeated his experimentsDisproved "Spontaneous Generation" Fig 1.26 page 20 "Swan-necked Flask" experiment.Unlike others, his specially designed glassware enabled the "life force" (air) into the flask, and still no bacteria grew until the neck of the flask was broken off.

Cell wall:

G+ bacteria have a thick peptidoglycan layer in their cell walls, which retains the crystal violet stain in the Gram stain test, giving them a purple color. G- bacteria have a thinner peptidoglycan layer surrounded by an outer membrane, which does not retain the crystal violet stain and is instead stained pink by the counterstain in the Gram stain test.

Periplasmic space:

G- bacteria have a periplasmic space between the inner and outer membranes, which contains various enzymes, transport proteins, and other molecules involved in nutrient uptake, signaling, and defense. G+ bacteria have a smaller periplasmic space or lack one altogether.

Outer membrane:

G- bacteria have an outer membrane that contains lipopolysaccharides, porins, and other proteins. The outer membrane acts as a protective barrier against environmental stressors such as antibiotics, detergents, and host immune defenses. G+ bacteria lack an outer membrane and have a thick peptidoglycan layer that provides structural support and protection.

Divine punishment

God or the gods. It was believed that illness was a punishment for sins,

. Fimbrae/Pili:

Hair-like appendages found on the surface of some bacteria, used for attachment to surfaces and other bacteria, and in some cases for the transfer of genetic material.

Types of microbial products that are used in Industry and Medicine as well as Model systems that have informed Modern Genetics.

Industrial microbiology: Microorganisms are used in a variety of industrial processes, such as fermentation for the production of food, beverages, and industrial chemicals. For example, yeasts and bacteria are used in the production of beer, wine, and bread, while bacteria and fungi are used in the production of antibiotics, enzymes, and other chemicals. Medical microbiology: Microorganisms are used in medicine for the production of vaccines, antibiotics, and other drugs. For example, bacteria such as Escherichia coli and yeast are used to produce insulin for the treatment of diabetes, while bacteria and fungi are used to produce antibiotics such as penicillin. Model systems in genetics: Certain microorganisms have been used as model systems in genetics research due to their simple genomes and ease of genetic manipulation. For example, the bacterium Escherichia coli has been used as a model system to study gene regulation and DNA replication, while the yeast Saccharomyces cerevisiae has been used to study cell cycle control and DNA repair mechanisms.

The difference between intracellular vs. membrane-bound components of Prokaryotes.

Intracellular components: Prokaryotes have a nucleoid region that contains the genetic material, typically a circular DNA molecule. The DNA is not enclosed within a nuclear membrane but is condensed and organized by proteins. Prokaryotes have ribosomes, which are responsible for protein synthesis. Bacterial ribosomes are smaller than eukaryotic ribosomes and have a different composition of RNA and proteins. Prokaryotes can have inclusion bodies, which are intracellular storage structures for nutrients, such as glycogen, lipids, or phosphate. Membrane-bound components: Prokaryotes have a cell membrane, also called the plasma membrane, which encloses the cell and regulates the exchange of molecules between the cell and its environment. The membrane is composed of phospholipids and embedded proteins. Some prokaryotes have an outer membrane, which is a lipid bilayer that surrounds the cell wall. It is found only in Gram-negative bacteria and is involved in various functions such as nutrient uptake, toxin secretion, and protection against the host immune system. Prokaryotes may have pili or fimbriae, which are short hair-like structures on the cell surface that are involved in attachment, motility, or conjugation. Some prokaryotes have flagella, which are long whip-like structures on the cell surface that are involved in motility.

Ways in which bacteria Sense and Respond to their environment

Many bacteria genetically regulate the expression of their pili/adherence in response to their environment and as a result, at a given time are either Planktonic - Free swimming (loose) or Sessile - Attached (often as part of a biofilm)

Miasmas and Humors - what are these?

Miasmas, Divine punishment humors

Membrane-bound components:

Prokaryotes have a cell membrane, also called the plasma membrane, which encloses the cell and regulates the exchange of molecules between the cell and its environment. The membrane is composed of phospholipids and embedded proteins. Some prokaryotes have an outer membrane, which is a lipid bilayer that surrounds the cell wall. It is found only in Gram-negative bacteria and is involved in various functions such as nutrient uptake, toxin secretion, and protection against the host immune system. Prokaryotes may have pili or fimbriae, which are short hair-like structures on the cell surface that are involved in attachment, motility, or conjugation. Some prokaryotes have flagella, which are long whip-like structures on the cell surface that are involved in motility.

Intracellular components:

Prokaryotes have a nucleoid region that contains the genetic material, typically a circular DNA molecule. The DNA is not enclosed within a nuclear membrane but is condensed and organized by proteins. Prokaryotes have ribosomes, which are responsible for protein synthesis. Bacterial ribosomes are smaller than eukaryotic ribosomes and have a different composition of RNA and proteins. Prokaryotes can have inclusion bodies, which are intracellular storage structures for nutrients, such as glycogen, lipids, or phosphate.

Evolution

Scientist estimate the Earth Formed 4.5 Bya years ago billion

The similarities and differences between Prokaryotic and Eukaryotic organisms

Similarities: Both prokaryotic and eukaryotic organisms are made up of cells, which are the basic unit of life. Both prokaryotic and eukaryotic cells contain genetic material in the form of DNA. Both types of cells hav.e a cell membrane that regulates the movement of materials into and out of the cell. Both types of cells use ribosomes to synthesize proteins Differences: Size: Prokaryotic cells are typically smaller than eukaryotic cells, ranging in size from 0.1 to 5 micrometers, while eukaryotic cells are generally larger, ranging from 10 to 100 micrometers. Nucleus: Prokaryotic cells lack a nucleus, whereas eukaryotic cells have a distinct, membrane-bound nucleus that houses the genetic material. Organelles: Prokaryotic cells lack membrane-bound organelles, such as mitochondria, chloroplasts, endoplasmic reticulum, and Golgi apparatus, while eukaryotic cells have these organelles.

The differences between Prokaryotic and Eukaryotic organisms

Size: Prokaryotic cells are typically smaller than eukaryotic cells, ranging in size from 0.1 to 5 micrometers, while eukaryotic cells are generally larger, ranging from 10 to 100 micrometers. Nucleus: Prokaryotic cells lack a nucleus, whereas eukaryotic cells have a distinct, membrane-bound nucleus that houses the genetic material. Unicellular prok Multicellular =eukar Organelles: Prokaryotic cells lack membrane-bound organelles, such as mitochondria, chloroplasts, endoplasmic reticulum, and Golgi apparatus, while eukaryotic cells have these organelles.

gas vesicles

Structures found in some aquatic bacteria that provide buoyancy and allow the bacteria to move up and down in the water column. They are composed of a protein shell and contain a gas, usually nitrogen or oxygen. The molecules that make up some of these structures include lipids and proteins in the cytoplasmic membrane, peptidoglycan subunits in the cell wall, lipopolysaccharides in the outer membrane, and polysaccharides in the capsule. Fimbrae and pili are composed of proteins, and gas vesicles are made of a protein shell.

The Gram stain involves four steps:

The bacterial sample is first stained with crystal violet, which binds to the peptidoglycan layer in both Gram-positive and Gram-negative bacteria. Then, the sample is treated with iodine, which acts as a mordant, fixing the crystal violet within the bacterial cell. The sample is then washed with a decolorizing solution, such as alcohol or acetone. In Gram-positive bacteria, the thick layer of peptidoglycan retains the crystal violet, while in Gram-negative bacteria, the outer membrane is disrupted, allowing the crystal violet to be washed away. Finally, the sample is counterstained with a contrasting dye, such as safranin, which stains the decolorized Gram-negative bacteria pink or red. As a result of this staining process, Gram-positive bacteria appear purple, while Gram-negative bacteria appear pink or red.

Taxonomic Categories from Domains to Species and where Archaea and Bacteria fit in, which are prokaryotic and which are eukaryotic.(Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species)

The taxonomic categories, from the highest level to the lowest, are: Domain Kingdom Phylum (or Division for some groups) Class Order Family Genus Species There are three domains of life: Bacteria, Archaea, and Eukarya. Archaea and Bacteria are both prokaryotic organisms, meaning they lack a distinct nucleus and membrane-bound organelles, while Eukarya are eukaryotic organisms, which possess a nucleus and other membrane-bound organelles. The taxonomic classification of Archaea and Bacteria is as follows: Archaea: Domain: Archaea Kingdom: Archaea Bacteria: Domain: Bacteria Kingdom: Bacteria

Examples of beneficial microbes (Escherichia coli, Lactobacillus) and relevance of our microbiome to our health as well as Probiotics.

There are many beneficial microbes that are important to our health. Two examples of beneficial microbes are Escherichia coli and Lactobacillus. Escherichia coli (E. coli): E. coli is a bacterium that is found in the gut of humans and other animals. While some strains of E. coli can cause illness, most strains are harmless and even beneficial. E. coli produces vitamin K2, which is important for blood clotting, and helps to prevent the growth of harmful bacteria in the gut. Lactobacillus: Lactobacillus is a genus of bacteria that is found in many fermented foods, such as yogurt, sauerkraut, and kefir. These bacteria are known for their probiotic properties, which means they can help to improve digestive health, boost the immune system, and even improve mental health. Probiotics are live microorganisms that can be consumed to help improve the balance of the microbiome. They are often found in fermented foods, such as yogurt, and can also be taken as supplements. Probiotics have been shown to have a variety of health benefits, including improving digestive health, boosting the immune system, and even reducing symptoms of depression and anxiety.

Cellular Inclusions:

Various types of structures found within bacterial cells that are used for storage of nutrients or other molecules. Examples include glycogen granules, polyphosphate granules, and gas vesicles.

sessile bacteria

adherent organisms, encased in an extracellular polymeric substance

There are different types of chemotaxis,

aerotaxis (oxygen), phototaxis (light), thermotaxis (temperature), and osmotaxis (osmotic pressure).

There are many beneficial microbes that are important to our health. Two examples of beneficial microbes are

are Escherichia coli and Lactobacillus.

Endospores

are a unique form of bacterial survival mechanism that can withstand harsh environmental conditions. They are highly resistant to heat, radiation, chemicals, and desiccation.

Fungi:

are eukaryotic organisms that include yeasts, molds, and mushrooms. They are heterotrophic, meaning they obtain energy by breaking down organic matter. Fungi play important roles in nutrient cycling and decomposition in ecosystems. Some fungi also form mutualistic relationships with other organisms, such as mycorrhizal fungi that form symbiotic associations with plant roots.

Probiotics

are live microorganisms that can be consumed to help improve the balance of the microbiome. They are often found in fermented foods, such as yogurt, and can also be taken as supplements.

The similarities between Prokaryotic and Eukaryotic organisms

are made up of cells, which are the basic unit of life. cells contain genetic material in the form of DNA. cell membrane that regulates the movement of materials into and out of the cell. cells use ribosomes to synthesize proteins

LPS:

are molecules found in the outer membrane of Gram-negative bacteria. They consist of a lipid portion (lipid A) and a polysaccharide portion (O-antigen), and are involved in bacterial pathogenesis and immune evasion.

Protozoa:

are single-celled eukaryotic organisms that are found in aquatic and soil environments. They are diverse in shape and size, and can be free-living or parasitic. Protozoa can obtain energy through various means such as photosynthesis or by feeding on other organisms. Some protozoa play important roles in aquatic food webs, while others can cause diseases in humans and other animals.

When conditions become favorable again,

endospores can germinate and convert back to vegetative cells. This process involves the activation of enzymes that break down the spore coat and cortex, allowing the vegetative cell to emerge.

. Endospores are formed

environmental conditions become unfavorable for bacterial growth.

Bacterial endospores

highly resistant, dormant structures that are produced by certain species of bacteria, such as Bacillus and Clostridium. are formed within the bacterial cell . are highly resistant to environmental stresses such as heat, radiation, and chemicals, When conditions become more favorable, \ can germinate and grow into active bacterial cells. are produced by only a few species of bacteria, highly resistant structures that can survive in harsh environmental conditions,

The process of sporulation involves several stages,

including DNA replication, asymmetric cell division, and formation of the cortex and spore coat. During sporulation, the bacteria produce specialized proteins called SASPs (small acid-soluble spore proteins) that help protect the DNA from damage. Dipicolinic acid and calcium ions also play an important role in endospore formation by stabilizing the spore structures.

Escherichia coli (E. coli):

is a bacterium that is found in the gut of humans and other animals. While some strains of E. coli can cause illness, most strains are harmless and even beneficial. E. coli produces vitamin K2, which is important for blood clotting, and helps to prevent the growth of harmful bacteria in the gut.

Lactobacillus

is a genus of bacteria that is found in many fermented foods, such as yogurt, sauerkraut, and kefir. These bacteria are known for their probiotic properties, which means they can help to improve digestive health, boost the immune system, and even improve mental health.

two main structural molecules of peptidoglycan

is a major component of the cell wall of most bacteria, and is composed of two main structural molecules: N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). NAG and NAM molecules are linked together by glycosidic bonds to form a long polysaccharide chain. These chains are then cross-linked by short peptide chains, which are attached to the NAM molecules. The peptide chains are composed of alternating D- and L-amino acids, and are connected by peptide bonds. The cross-linking between adjacent peptide chains is mediated by enzymes called transpeptidases, which form covalent bonds between the amino acids.

Main structural molecules of Peptidoglycan, how they fit together, and the role of Peptidoglycan for the cell.

is a major component of the cell wall of most bacteria, and is composed of two main structural molecules: N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). NAG and NAM molecules are linked together by glycosidic bonds to form a long polysaccharide chain. These chains are then cross-linked by short peptide chains, which are attached to the NAM molecules. The peptide chains are composed of alternating D- and L-amino acids, and are connected by peptide bonds. The cross-linking between adjacent peptide chains is mediated by enzymes called transpeptidases, which form covalent bonds between the amino acids. The resulting peptidoglycan structure forms a strong mesh-like layer around the bacterial cell, providing structural support and protection against osmotic pressure. The peptidoglycan layer also helps to maintain the shape of the cell and provides a barrier to the entry of certain drugs and toxins.

Flagella

long, whip-like appendages that bacteria use for motility.

The basal body consists of the

of the Mot and C, P, L rings. The Mot protein acts as a rotor, powered by the proton motive force, while the rings anchor the flagellum to the cell wall and allow it to rotate.

Humors

out of Balance. Doctors used blood-letting or purgatives to balance them out (humors = blood, bile, phlegm...)

thick cortex layer made of

peptidoglycan.

Fungal spores,

produced by fungi and are typically used for reproduction can be produced both sexually and asexually and can take a variety of forms, can be dispersed by wind, water, or animals and can be an important factor in the spread of fungal infections. are produced by a wide range of fungi. Additionally, are typically produced for reproductive purposes and are not as resistant. factor

role of peptidoglycan

providing structural support and protection against osmotic pressure. also helps to maintain the shape of the cell and provides a barrier to the entry of certain drugs and toxins.

The difference between Spontaneous Generation and the Germ Theory of Disease.

spontaneous generation was an outdated idea that living organisms could arise from non-living matter, while the germ theory of disease is the idea that diseases are caused by microorganisms. The germ theory of disease is widely accepted today and has led to significant advancements in medicine and public health.

chemoreceptors

that bind to specific chemical signals and trigger changes in the direction of flagellar rotation.

How size to volume ratio is relevant in bacteria

the small size and high surface area to volume ratio of bacteria play an important role in their physiology, allowing them to efficiently take up nutrients, remove waste, reproduce rapidly, and interact with their environment.

Chemotaxis is the ability of bacteria

to sense and move towards or away from chemical gradients in their environment. This is achieved through the use of

in e-coli while CW rotation causes

tumbling, which helps the cell change direction

. Transmission electron microscope (TEM)

uses a beam of electrons to image a thin section of a sample. This allows for high-resolution imaging of the internal structure of cells and tissues, as well as other materials. .

Scanning electron microscope (SEM):

uses a beam of electrons to scan the surface of a sample, creating a detailed 3D image. It is commonly used in materials science, biology,

Fluorescence microscope:

uses a high-intensity light source to excite fluorescent molecules in a sample. This allows for imaging of specific structures or molecules within a cell or tissue. It is commonly used in biological research, such as to visualize fluorescently labeled proteins in cells.