Secondary Active Transport
| Approach | What it tests | | :--- | :--- | | | Remove external Na⁺ → transport stops (proves Na⁺ dependence) | | Oubain (Na⁺/K⁺ pump inhibitor) | Transport gradually stops as Na⁺ gradient collapses (indirect proof) | | Valinomycin (K⁺ ionophore) | Changes membrane potential; affects electrogenic transport | | Vesicle assays | Load vesicles with high Na⁺ inside, then add external substrate – uptake occurs without ATP |
Glucose concentration inside the cell can be 10–100× higher than outside – all without direct ATP use.
| ❌ Wrong | ✅ Correct | | :--- | :--- | | "Secondary active transport uses ATP directly." | It uses the gradient created by primary transport. No ATP is hydrolyzed by the transporter. | | "It only moves one type of molecule." | It always moves two solutes (or one solute and one ion). | | "Symport and antiport work the same way." | Symport moves both in same direction; antiport moves them opposite. | | "The ion always moves in the same direction as the solute." | In antiport, the ion moves opposite to the second solute. | secondary active transport
Depending on which direction the "hitchhiking" molecule is traveling, secondary active transport is categorized into two types: 1. Symport (Cotransport)
diagram ideas to go along with this post? AI can make mistakes, so double-check responses Copy Creating a public link... You can now share this thread with others Good response Bad response 15 sites Active transport: primary & secondary overview (article) In secondary active transport, the two molecules being transported may move either in the same direction (i.e., both into the cell... Khan Academy Active transport: primary & secondary overview (article) Secondary active transport * The electrochemical gradients set up by primary active transport store energy, which can be released ... Khan Academy Active transport: primary & secondary overview (article) Secondary active transport. The electrochemical gradients set up by primary active transport store energy, which can be released a... Khan Academy General principles of secondary active transporter function - PMC Secondary transport is driven by an electrochemical gradient in a driving ion, namely, sodium or protons. A few well-studied examp... PubMed Central (PMC) (.gov) General principles of secondary active transporter function Secondary transport is driven by an electrochemical gradient in a driving ion, namely, sodium or protons. A few well-studied examp... PubMed Central (PMC) (.gov) 5.12: Active Transport - Secondary Active Transport Nov 22, 2024 — | Approach | What it tests | |
Understanding Secondary Active Transport: The Cell’s Clever Energy Recycler
The process of secondary active transport involves two key components: | | "It only moves one type of molecule
Secondary active transport does not use ATP directly. However, it is entirely dependent on primary active transport to maintain the gradient that fuels it. The Two Main Types: Symport vs. Antiport
In a symport system, both substances move in the .