This lesson explores how cells transfer electrons during respiration, where the electron transport system (ETS) operates in prokaryotes and eukaryotes, and how aerobic and anaerobic respiration differ.
The electron transport system (ETS) is a series of membrane-associated protein complexes and mobile electron carriers. It receives high-energy electrons carried by NADH and FADH₂, which are produced during glycolysis, the transition reaction, and the Krebs cycle.
All flashcards
What is the electron transport system (ETS)?
A series of membrane-associated protein complexes and mobile carriers that transfer electrons to a final acceptor and help establish an H⁺ gradient.
What is proton motive force (PMF)?
The potential energy stored in the electrochemical gradient created by an unequal distribution of H⁺ across a membrane.
What is chemiosmosis?
The movement of H⁺ down its electrochemical gradient through ATP synthase, powering ATP formation.
How do aerobic and anaerobic respiration differ in their final electron acceptors?
Aerobic respiration uses oxygen; anaerobic respiration uses another inorganic acceptor, such as nitrate.
How does substrate-level phosphorylation produce ATP?
An enzyme transfers a phosphate group directly from a phosphorylated molecule to ADP.
Quiz questions
In a eukaryotic mitochondrion, which direction do protons flow through ATP synthase during respiration?Answer: From the intermembrane space into the matrix.
Which feature distinguishes anaerobic respiration from fermentation?Answer: Anaerobic respiration uses an ETS and an external inorganic electron acceptor.
How does substrate-level phosphorylation form ATP?Answer: An enzyme transfers phosphate directly from a phosphorylated molecule to ADP.
In the theoretical accounting described for complete aerobic respiration, what is the maximum ATP yield per glucose?Answer: 38 ATP.
Besides ATP production, which cellular process can proton motive force help drive?Answer: Flagellar rotation.
Based on Microbiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister, Brian M. Forster (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.