IB Biology Topic B2.1.6 Channel Proteins for Facilitated Diffusion Revision Notes (SL/HL)

IB Biology Topic B2.1.6 Channel Proteins for Facilitated Diffusion Revision Notes (SL/HL) | RevisionDojo

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Facilitated Diffusion: Channel Proteins Give Ions a Hydrophilic Pore

The phospholipid bilayer blocks most polar molecules and ions.
Proteins called channel proteins let these substances cross instead.
This movement is called facilitated diffusion, and it uses no cell energy.

Common Mistake

Facilitated diffusion is still passive transport, not active.
It simply uses a channel to help the diffusion happen.

Channel Proteins Are Selective Pores Through the Membrane

Definition

Channel protein

A specialized protein embedded in the membrane, allowing specific ions or molecules to diffuse across.

Each channel protein has a pore that connects the cytoplasm to the watery environment outside the cell.
Each channel is highly specific, usually letting just one type of particle pass.
1. Sodium ion (Na⁺) channels pass only sodium ions.

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Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Facilitated Diffusion: Channel Proteins Give Ions a Hydrophilic Pore

The phospholipid bilayer blocks most polar molecules and ions.
Proteins called channel proteins let these substances cross instead.
This movement is called facilitated diffusion, and it uses no cell energy.

Common Mistake

Facilitated diffusion is still passive transport, not active.
It simply uses a channel to help the diffusion happen.

Channel Proteins Are Selective Pores Through the Membrane

Definition

Channel protein

A specialized protein embedded in the membrane, allowing specific ions or molecules to diffuse across.

Each channel protein has a pore that connects the cytoplasm to the watery environment outside the cell.
Each channel is highly specific, usually letting just one type of particle pass.
1. Sodium ion (Na⁺) channels pass only sodium ions.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic B2.1.6: Channel Proteins for Facilitated Diffusion Notes

Facilitated Diffusion: Channel Proteins Give Ions a Hydrophilic Pore

Channel Proteins Are Selective Pores Through the Membrane

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

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Facilitated Diffusion: Channel Proteins Give Ions a Hydrophilic Pore

Channel Proteins Are Selective Pores Through the Membrane

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics