Microbial Extremophiles Lecture Quiz

<p>Metabolic dependency or predation (D)</p> Signup and view all the answers

<p>Cellular adaptations to extreme habitats (B)</p> Signup and view all the answers

<p>Limpets and octopi (D)</p> Signup and view all the answers

<p>It is oxidised by Beggiatoa to produce elemental sulfur. (B)</p> Signup and view all the answers

<p>To act as a reserve of elemental sulfur, which can be metabolized later. (C)</p> Signup and view all the answers

<p>Up to 100 micrometers, or even longer (B)</p> Signup and view all the answers

<p>In the sediment above the reduced zone. (A)</p> Signup and view all the answers

<p>It is converted into sulphate through further metabolism. (C)</p> Signup and view all the answers

<p>The presence of intracellular sulfur granules (D)</p> Signup and view all the answers

<p>Lithoautotroph (A)</p> Signup and view all the answers

<p>It oxidizes pyrite (FeS2) to produce H2SO4. (B)</p> Signup and view all the answers

<p>It neutralizes excess protons (H+) that enter the cell. (D)</p> Signup and view all the answers

<p>It acts as an electron acceptor in the spontaneous oxidation of FeS2. (B)</p> Signup and view all the answers

<p>It reduces the availability of key trace elements like aluminium. (A)</p> Signup and view all the answers

<p>Fe3+ becomes the primary electron acceptor, further increasing amounts of Fe2+ and thus decreasing pH. (B)</p> Signup and view all the answers

<p>Iron requires more energy to release and therefore donate its electrons. (D)</p> Signup and view all the answers

<p>The soil's ability to neutralize H+ ions and acid compounds. (B)</p> Signup and view all the answers

<p>Between 6 and 8, though some are naturally more acidic. (C)</p> Signup and view all the answers

<p>It binds to and stabilizes dissolved and particulate iron, facilitating its dispersion. (D)</p> Signup and view all the answers

<p>Iron and sulphur (D)</p> Signup and view all the answers

<p>By producing rigid deposits of filamentous mats composed of elemental sulphur. (A)</p> Signup and view all the answers

<p>They predate upon microbial mats produced by bacteria. (D)</p> Signup and view all the answers

<p>They are the most heat-tolerant complex life form on Earth, withstanding 105°C water. (A)</p> Signup and view all the answers

<p>$Fe^{2+}$ + $FeS$ + $O_2$ $ ightarrow$ $Fe(OH)_3$ followed by particle sedimentation. (B)</p> Signup and view all the answers

<p>It is utilized by sulphur-metabolizing organisms before reaching oxic zones. (C)</p> Signup and view all the answers

<p>Using energy from the oxidation of sulphides. (C)</p> Signup and view all the answers

<p>Desulfovibrio and Desulfococcus (C)</p> Signup and view all the answers

<p>To produce methane and sulfate, which the bacteria then convert. (B)</p> Signup and view all the answers

<p>Bicarbonate and sulfide (A)</p> Signup and view all the answers

<p>Hydrogen Sulfide ($HS^-$) (A)</p> Signup and view all the answers

<p>To obtain sufficient $H_2S$ from the sediment. (B)</p> Signup and view all the answers

<p>The trophosome. (C)</p> Signup and view all the answers

<p>Nutrients synthesized by their symbiotic bacteria (A)</p> Signup and view all the answers

<p>To obtain chemical compounds from the sediment. (D)</p> Signup and view all the answers

<p>Aerobic sediment is closer to the sea bed than anaerobic sediment. (D)</p> Signup and view all the answers

<p>Oxidation of reduced inorganic sulfur compounds (B)</p> Signup and view all the answers

<p>Psychrophiles (B)</p> Signup and view all the answers

<p>Incorporating unsaturated fatty acids into cell membranes (B)</p> Signup and view all the answers

<p>Exopolysaccharide (A)</p> Signup and view all the answers

<p>Biofilm (D)</p> Signup and view all the answers

<p>Aerobes are predominant near the surface (C)</p> Signup and view all the answers

<p>Dissimilatory nitrate/nitrite reduction (B)</p> Signup and view all the answers

Habitats with conditions that are outside the range of what is considered 'normal' for most life forms. These conditions can be extremely hot, cold, acidic, saline, or have other extreme features.

Organisms that live in extreme environments. These organisms are very specialized to survive in their unique habitats.

Environments that are very acidic, with a pH lower than that of most natural environments. Many bacteria and archaea are well-adapted to survive in acidic environments.

Environments that have a high concentration of salt, much higher than what is found in seawater. There are specialized organisms that can tolerate these high salt concentrations.

The ability of organisms to adjust their body functions or structures to survive in harsh environments. These adaptations can be physiological, biochemical, or even anatomical.

The process of oxidizing pyrite (FeS2) by the bacteria Thiobacillus ferroxidans, resulting in the production of sulfuric acid (H2SO4).

The flow of acidic water from mine sites due to the oxidation of pyrite, leading to a decrease in pH.

The ability of living organisms to survive and thrive in environments with high acidity.

The oxidation of ferrous iron (Fe2+) to ferric iron (Fe3+) due to exposure to atmospheric oxygen, contributing to the increase in acidity.

The process of using iron as an electron donor to drive the production of energy (ATP) in acid-tolerant microbes.

The process of maintaining a steady pH inside a cell by neutralizing excess protons (H+).

The ability of substances, such as soil, to resist changes in pH, usually by reacting with acidic compounds.

The alteration of the chemical composition of natural waters, particularly in lakes and streams, due to the presence of acidic compounds, impacting the survival of aquatic organisms.

A symbiotic relationship where Archaea produce methane and sulfate, which are then consumed by Eubacteria, resulting in bicarbonate and sulfide.

A metabolic process that occurs in deep-sea sediments, where methane is oxidized by sulfate-reducing bacteria, resulting in bicarbonate and sulfide.

A tube-dwelling marine worm that lives near hydrothermal vents, relying on a symbiotic relationship with bacteria for its energy.

The organ in Vestimentiferan worms where symbiotic bacteria live and convert sulfide into usable energy.

Root-like structures in Vestimentiferan worms that extend into the sediment to absorb sulfide.

The chemical compound H2S, which is a key energy source for Vestimentiferan worms.

A type of bacteria that is responsible for reducing sulfate to sulfide in the anaerobic oxidation of methane.

The chemical compound CH4, which is oxidized by sulfate-reducing bacteria in the anaerobic oxidation of methane.

A type of bacteria that can oxidize hydrogen sulfide (H2S) into elemental sulfur, which they store as granules within their cells.

The process where an organism uses inorganic compounds as a source of energy.

A chemical compound that is made up of two hydrogen atoms and one sulfur atom. It has a characteristic rotten egg smell.

An element that is crucial for life, but can be toxic in high concentrations. It's found in many minerals and is a key component of proteins.

The process where an organism uses elemental sulfur as an energy source.

A chemical compound that is made up of one sulfur atom and four oxygen atoms. It is found in many natural environments.

The process where organisms convert elemental sulfur into sulfate.

The collection of interconnected biological processes that cycle sulfur through different forms in the environment.

These bacteria use reduced sulfur compounds as an energy source for carbon fixation, providing nutrients to the host worm.

Organisms that thrive in cold environments, including ice and sub-zero waters.

The protective layer formed by a community of microbes embedded in a self-produced extracellular matrix.

Microbial communities in ice crystals and sub-zero waters.

A method to analyze RNA sequences, detecting genes involved in photosynthesis.

The process where microorganisms convert nitrate or nitrite into nitrogen gas.

Iron is a key nutrient for marine life, particularly primary producers. However, it's often scarce in the ocean.

Hydrothermal vents release iron, but it usually precipitates out quickly. However, organic molecules can bind to iron, keeping it dissolved and allowing it to spread further.

Tiny particles of iron sulfide (FeS2, also known as pyrite), less than 200 nanometers in size, contribute significantly to the overall iron content in hydrothermal plumes.

Carbon dioxide from the environment is incorporated into organic molecules (cell carbon) by using energy from the oxidation of sulfides.

Arcobacter bacteria create protective mats of elemental sulfur, enabling them to thrive in harsh, sulfide-rich, high-flow environments.

Pompeii worms, also called Alvinella worms, feed on microbial mats rich in bacteria and sulfur compounds, taking advantage of this unique source of food.

The Pompeii worm, a close relative of tubeworms, is extremely tolerant of heat. It can withstand temperatures as high as 105°C, making it the most heat-tolerant complex life form on Earth.

Different processes lead to the removal of iron from the water column: iron sulfide and iron hydroxide precipitate, forming particles that sink to the seabed.