Skip to main content
Pearson+ LogoPearson+ Logo
Ch. 26 - Bacteria and Archaea
Freeman - Biological Science 7th Edition
Freeman7th EditionBiological ScienceISBN: 9783584863285Not the one you use?Change textbook
Chapter 26, Problem 2

What are organisms called that use inorganic compounds as electron donors in cellular respiration?
a. Phototrophs
b. Heterotrophs
c. Organotrophs
d. Lithotrophs

Verified step by step guidance
1
Begin by understanding the concept of electron donors in cellular respiration. Electron donors are substances that provide electrons to the electron transport chain, which is crucial for ATP production.
Recognize that organisms can be classified based on the type of electron donors they use. Inorganic compounds, such as hydrogen sulfide or ammonia, are used by certain organisms as electron donors.
Learn the term 'lithotrophs.' Lithotrophs are organisms that use inorganic compounds as electron donors. The prefix 'litho-' refers to 'rock' or 'mineral,' indicating the use of inorganic substances.
Differentiate lithotrophs from other types of organisms: phototrophs use light as an energy source, heterotrophs consume organic compounds, and organotrophs use organic compounds as electron donors.
Conclude that the correct term for organisms that use inorganic compounds as electron donors in cellular respiration is 'lithotrophs.'

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
24s
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Cellular Respiration

Cellular respiration is a metabolic process in which cells convert nutrients into energy, typically in the form of ATP. This process can occur through various pathways, including aerobic and anaerobic respiration, depending on the availability of oxygen and the type of electron donors used.
Recommended video:
Guided course
03:39
Introduction to Cellular Respiration

Electron Donors

Electron donors are substances that provide electrons during biochemical reactions, particularly in cellular respiration. They play a crucial role in the electron transport chain, where the transfer of electrons leads to the production of ATP. Different organisms utilize various types of electron donors, including organic compounds and inorganic substances.
Recommended video:
Guided course
07:41
Electron Transport Chain

Lithotrophs

Lithotrophs are organisms that obtain energy by oxidizing inorganic compounds, such as hydrogen sulfide or ammonia, using them as electron donors in cellular respiration. This group includes certain bacteria and archaea that thrive in extreme environments and play essential roles in biogeochemical cycles.
Recommended video:
Guided course
03:21
Electron Source: Lithotrophs vs. Organotrophs