2026-08-17 13:56:29: Mechanisms of Transportation

This commit is contained in:
2026-08-17 13:56:31 -04:00
parent ffeaee957a
commit 73f30ad6e1
2 changed files with 64 additions and 11 deletions
+26 -11
View File
@@ -216,9 +216,23 @@
"icon": "lucide-file",
"title": "Tonicity and Osmoregulation"
}
},
{
"id": "d0594e201045a677",
"type": "leaf",
"state": {
"type": "markdown",
"state": {
"file": "biology/Cell Structure and Function/Mechanisms of Transport.md",
"mode": "source",
"source": false
},
"icon": "lucide-file",
"title": "Mechanisms of Transport"
}
}
],
"currentTab": 14
"currentTab": 15
},
{
"id": "25da4f0a48a8e7cd",
@@ -402,18 +416,22 @@
"obsidian-excalidraw-plugin:New drawing": false
}
},
"active": "eb113c7264f89721",
"active": "d0594e201045a677",
"lastOpenFiles": [
"Pasted image 20260817125829.png",
"biology/Cell Structure and Function/Tonicity and Osmoregulation.md",
"biology/Cell Structure and Function/Facilitated Diffusion.md",
"biology/Cell Structure and Function/Membrane Permeability.md",
"biology/Cell Structure and Function/Membrane Transport.md",
"biology/Cell Structure and Function/Origins of Cell Compartmentalization.md",
"biology/Cell Structure and Function/Cell Structure and Function.md",
"biology/Cell Structure and Function/Facilitated Diffusion.md",
"biology/Cell Structure and Function/Membrane Transport.md",
"biology/Cell Structure and Function/Tonicity and Osmoregulation.md",
"biology/Chemistry of Life/Lipids.md",
"physics/Work Energy and Power/Work.md",
"physics/Work Energy and Power/Power.md",
"biology/Cell Structure and Function/Mechanisms of Transport.md",
"Pasted image 20260817125829.png",
"biology/Cell Structure and Function/Membrane Permeability.md",
"biology/Cell Structure and Function/Plasma Membrane.md",
"root.md",
"biology/Cell Structure and Function/Cell Size.md",
"biology/Cell Structure and Function/Cell Structure and Function.md",
"Assets/Pasted image 20260817123835.png",
"Assets/Pasted image 20260817121113.png",
"Assets/Pasted image 20260817121129.png",
@@ -426,8 +444,6 @@
"biology/Chemistry of Life/Elements of Life.md",
"biology/Chemistry of Life/Carbohydrates.md",
"chemistry/Matter and Chemical Bonding.md",
"physics/Work Energy and Power/Power.md",
"physics/Work Energy and Power/Work.md",
"physics/Work Energy and Power/Work Energy and Power.md",
"literacy/buzzwords.md",
"literacy/fallacies.md",
@@ -435,7 +451,6 @@
"physics/Work Energy and Power/Potential Energy.md",
"physics/Work Energy and Power/Translational Kinetic Energy.md",
"physics/Force and Translational Dynamics/Conservation of Energy.md",
"biology/Chemistry of Life/Lipids.md",
"Assets/Pasted image 20260816081041.png",
"physics/Work Energy and Power",
"Assets/Pasted image 20260816073410.png",
@@ -0,0 +1,38 @@
[[Cell Structure and Function]]
Mechanisms of active transport.
# Summary
* Active transport moves substances against their concentration gradient and requires energy, usually from ATP hydrolysis
* Membrane proteins (pumps) required for active transport. Bind to molecules and moves them.
* Na+/K+ pump (sodium potassium pump) moves 3 Na+ out and 2K+ in per ATP. Builds chemical and electric gradients.
* Unequal ion movement contribute to membrane potential, helping cell's separation of charges.
* Gradients store potential energy.
* Passive transport requires no energy and moves substances down the gradient.
# Why ATP Is Required
Requires metabolic energy. Uses hydrolysis to break ATP (adenosine triphosphate) ADP and inorganic phosphate (Pi), which releases energy that membrane proteins require. When ATP runs out, active transport stops.
# The Role of Membrane Proteins
Specialized membrane proteins:
* Act as pumps
* Undergo conformational changes using the ATP hydrolysis energy
* Selective for which molecules they bind to
* Moves substances across the membrane
# The Sodium-Potassium Pump: The Key Example
Na+/K+-ATPase is a transmembrane protein that:
* Runs continuously to maintain ion concentrations, since ions tend to equalize
* Acts as an ATPase enzyme, catalyzing the ATP hydrolysis
* Transports 3 Na+ out and 2K+ in per ATP
* Uses released energy to pump ions against gradient
Sodium potassium pumps use gradients that combine chemical and electric gradients.
Chemical Gradient:
* Keeps Na concentration higher outside cell
* Keeps K concentration higher inside cell
* Stores potential energy
Electrical Gradient:
* Because 3 positive ion leave for every 2 that enter, net loss of charge, making interior more negative
* Contributes to resting membrane potential
* Helps support nerve impulse transmission, muscle activity, nutrient uptake,