MICROBIOLOGY: EVOLV.SCI.-W/ACCESS>CI<
MICROBIOLOGY: EVOLV.SCI.-W/ACCESS>CI<
4th Edition
ISBN: 9780393622805
Author: SLONCZEWSKI
Publisher: Norton custom
bartleby

Concept explainers

bartleby

Videos

Question
Book Icon
Chapter 14, Problem 1RQ
Summary Introduction

To review:

The source and sink of electrons in respiration, lithotrophy, and photolysis.

Introduction:

An electron transport chain is a series of reactions in which the electron carrier transfers the electron to the carrier of the next- higher reduction potential (E) in a sequential manner. The electron flow is initiated with an initial electron donor from the outside of the cell that transfers the electrons to a terminal electron acceptor leaving the cell.

Expert Solution & Answer
Check Mark

Explanation of Solution

Lithotrophy is an energy-yielding form of metabolism in which many reduced minerals and single-carbon compounds can serve as electron donors. Many kinds of electron donors like metals and anions to single-carbon groups are included in lithotrophy. A specialized electron-accepting oxidoreductase is required by the electron donors like H2 (hydrogen), NH4+ (ammonium) or Fe2+ (ferrous). Compared to the organic donors such as glucose, inorganic substrates other than H2 are relatively poor electron donors due to which the terminal electron acceptor is usually a strong oxidant, such as O2 (oxygen), NO3- (nitrate) or Fe3+ (ferric ions).

In the process of photosynthesis, energy is derived from the photoexcitation of the light-absorbing pigment. The process of photolysis which is a light-driven separation of an electron from a molecule coupled to an electron transport chain is a consequence of photoexcitation. Photolysis is termed as “ light-reactions� that is coupled to “light-independent reactions� of carbon dioxide fixation in the plant chloroplast and cyanobacteria. The process of photoexcitation in ETS (electron transport system)-based photosynthesis causes the separation of the electron from a donor molecule like H2O (water) or H2S (hydrogen sulfide). The electrons are then transferred to an electron transport system which produces a proton potential and the reduced cofactor NADPH (nicotinamide adenine dinucleotide phosphate hydrogen). Proton potential is responsible to drive ATP (adenosine triphsophate) synthesis through an F1 and F0 ATP synthase.

Bacteria that are obligate aerobes grow only by using oxygen as the terminal electron acceptor like Sinorhizobiummeliloti. Although in anaerobic respiration, some bacteria and Archae use terminal electron acceptors like metals, oxidized ions of nitrogen and sulphur, and chlorinated organic molecules. In Escherichiacoli,different terminal oxidoreductases to reduce alternative electron acceptors are present which are termed as “reductases�. Some of the inorganic electron acceptors are nitrate (NO3) reduced to nitrite (NO2-) or NO2- reduced to NO (nitric oxide). The organic electron acceptors also play an important role in the process of food decomposition. In aerobic bacteria, the respiratory electron transport system leads to the formation of water by receiving electrons from NADH and FADH2 (flavin adenine dinucleotide dihydrogen) and transferring them to oxygen.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
We will be starting a group project next week where you and your group will research and ultimately present on a current research article related to the biology of a pathogen that infects humans. The article could be about the pathogen itself, the disease process related to the pathogen, the immune response to the pathogen, vaccines or treatments that affect the pathogen, or other biology-related study about the pathogen. I recommend that you choose a pathogen that is currently interesting to researchers, so that you will be able to find plenty of articles about it. Avoid choosing a historical disease that no longer circulates. List 3 possible pathogens or diseases that you might want to do for your group project.
not use ai please
DNK dagi nukleotidlar va undan sintezlangan oqsildagi peptid boglar farqi 901 taga teng bo'lib undagi A jami H boglardan 6,5 marta kam bo'lsa DNK dagi jami H bog‘lar sonini toping
Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Concepts of Biology
Biology
ISBN:9781938168116
Author:Samantha Fowler, Rebecca Roush, James Wise
Publisher:OpenStax College
Text book image
BIOLOGY:CONCEPTS+APPL.(LOOSELEAF)
Biology
ISBN:9781305967359
Author:STARR
Publisher:CENGAGE L
Text book image
Biology (MindTap Course List)
Biology
ISBN:9781337392938
Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg
Publisher:Cengage Learning
Text book image
Biochemistry
Biochemistry
ISBN:9781305577206
Author:Reginald H. Garrett, Charles M. Grisham
Publisher:Cengage Learning
Text book image
Biology: The Dynamic Science (MindTap Course List)
Biology
ISBN:9781305389892
Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan
Publisher:Cengage Learning
Text book image
Aquaculture Science
Biology
ISBN:9781133558347
Author:Parker
Publisher:Cengage
Photosynthesis & Respiration | Reactions | Chemistry | FuseSchool; Author: FuseSchool - Global Education;https://www.youtube.com/watch?v=3XIyweZg6Sw;License: Standard YouTube License, CC-BY