55 Questions
What is the process by which energy sources are oxidized to release electrons?
Oxidation
What is the energy currency of the cell, where the energy released from oxidation is stored?
ATP
Which type of microorganism derives energy from organic chemicals by oxidizing compounds to release electrons?
Aerobes
What are some examples of inorganic chemicals from which chemolithotrophs derive energy?
$H_2$, $H_2S$, and $Fe^{2+}$
What do methanogens in ruminant livestock produce as a by-product of digestion?
$CH_4$
What can inhibit methanogens in the rumen and reduce methane emissions in livestock?
Seaweed and tannins
What has resulted in up to an 80% reduction in methane emissions from cattle?
Feeding seaweed at 3% of the diet
What advantage do chemolithotrophs have over chemoorganotrophs?
They do not have to compete with chemoorganotrophs for energy sources.
What distinguishes autotrophs from heterotrophs?
Autotrophs use CO$_2$ as their carbon source.
What is the process by which bacteria divide?
Binary fission
In which growth phase of liquid bacterial culture do bacteria multiply at the highest rate?
Log phase
What are chemotrophs?
Organisms obtaining energy from chemical compounds
What is the primary function of photosynthesis in microorganisms?
To produce energy-rich organic compounds using light energy
$e^- + e^- \rightarrow e^- + e^-$ represents which process?
$Electron transfer$
What type of microorganisms have evolved to obtain carbon and energy from extreme habitats?
Autotrophs
What is the simplified model of energy production in microorganisms?
Fermentation and respiration
What is the chemical basis of energy production in microorganisms?
Chemical reactions involving the release of electrons
Which type of organisms obtain energy from sunlight?
Phototrophs
What is the primary function of chemotrophs?
Obtaining energy from chemical compounds
What is the main energy source for phototrophs?
Light
What is the primary function of carotenoids in phototrophic cells?
Photoprotective role
Where does photosynthesis take place in plant cells?
Chloroplasts
What is the bi-product of oxygenic photosynthesis?
$O_2$
What is the main difference between oxygenic and anoxygenic photosynthesis?
$O_2$ production
What gives phototrophic bacteria their green color?
$Chlorophylls$
Which of the following is a key feature of bacterial growth?
Bacteria divide by binary fission
What is the primary method of bacterial growth on solid medium?
Binary fission
How do bacteria primarily grow in liquid medium?
By binary fission
What are the direct measurements of bacterial growth?
Microscopic cell counts
What do chemotrophs use as their source of energy?
Chemical compounds
What is the primary energy source for phototrophs?
Light
What distinguishes chemoorganotrophs from chemolithotrophs?
Source of energy utilized
What do autotrophs use as their primary source of carbon?
Inorganic compounds
What distinguishes heterotrophs from autotrophs?
Source of carbon utilized
What is the key requirement for photosynthesis in microorganisms?
Light energy source
Which pigment is closely associated with bacteriochlorophyll but plays no direct role in photosynthesis?
Carotenoids
Where does photosynthesis take place in plant cells?
In the chloroplasts
What is the bi-product of oxygenic photosynthesis?
$O_2$
What do chemoorganotrophs and other organisms ultimately use as a source of organic matter?
Autotrophs
What is the energy source for phototrophs?
Light
What color are carotenoids associated with in phototrophic bacteria?
Green
What organelle is responsible for photosynthesis in plant cells?
Chloroplasts
What do phototrophs use as an energy source?
Light
What type of photosynthesis produces oxygen as a bi-product?
Oxygenic photosynthesis
What ultimately provides organic matter for chemoorganotrophs and other organisms?
Autotrophs
What is the process of oxidation?
Involves the loss of electrons
How is the energy released from oxidation stored in cells?
In the form of ATP
What do chemoorganotrophs derive energy from?
Organic chemicals
Which type of chemoorganotrophs can function without oxygen?
Anaerobes
What is a by-product of digestion produced by methanogens in ruminant livestock?
Methane
What can inhibit methanogens in the rumen and reduce methane emissions?
Synthetic chemicals
What has resulted in up to an 80% reduction in methane emissions from cattle?
Feeding seaweed at 3% of the diet
What do chemolithotrophs derive energy from?
Inorganic chemicals
What ecological niche advantage do chemolithotrophs have?
Do not have to compete with chemoorganotrophs for energy sources
What distinguishes autotrophs from heterotrophs?
Use $CO_{2}$ as their carbon source and are called primary producers because they produce organic matter from $CO_{2}$ in the air.
Study Notes
Microbial Energy Production and Methane Reduction in Livestock
- Oxidation involves the loss of electrons, while reduction involves the gain of electrons, with energy sources being oxidized to release electrons.
- The energy released from oxidation is stored in the form of ATP, the energy currency of the cell, through the removal of phosphate groups.
- Chemoorganotrophs derive energy from organic chemicals by oxidizing compounds to release electrons, which are used to generate ATP.
- There are different types of chemoorganotrophs, including aerobes, anaerobes, and facultative anaerobes, each with specific energy production characteristics.
- Methanogens in ruminant livestock, such as cattle and sheep, produce methane as a by-product of digestion, which is released into the atmosphere.
- Methane-reducing feed additives and supplements, including synthetic chemicals, natural supplements, and compounds like tannins and seaweed, can inhibit methanogens in the rumen and reduce methane emissions.
- Feeding seaweed at 3% of the diet has resulted in up to an 80% reduction in methane emissions from cattle, and active inhibitors like trihalomethanes can also decrease methane emissions.
- Chemolithotrophs derive energy from inorganic chemicals, such as H2, H2S, and Fe2+, and obtain carbon from CO2 through autotrophy.
- Chemolithotrophs have an ecological niche advantage as they do not have to compete with chemoorganotrophs for energy sources, and some of their energy sources are waste products from chemoorganotrophs.
- Heterotrophs use organic compounds as their carbon source, while autotrophs use CO2 as their carbon source and are called primary producers because they produce organic matter from CO2 in the air.
Test your knowledge about microbial energy production and methane reduction in livestock. Learn about the processes involved in energy production, the role of chemoorganotrophs and chemolithotrophs, and methods for reducing methane emissions in ruminant livestock.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
