IB Biology Topic B2.2.4 Adaptations of the Mitochondrion for Production of ATP by Aerobic Cell Respiration Revision Notes (HL)

IB Biology Topic B2.2.4 Adaptations of the Mitochondrion for Production of ATP by Aerobic Cell Respiration Revision Notes (HL) | RevisionDojo

Written by official IB examiners

The Mitochondrion: Where Aerobic Respiration Happens

The mitochondrion is a double-membrane organelle found in nearly all eukaryotic cells.
It is the site of aerobic cell respiration, the reactions that transfer energy from organic molecules to ATP.
1. Every structural feature of the mitochondrion relates directly to this function.
Mitochondria are typically sausage-shaped, roughly 1 to 5 µm long and 0.5 to 1 µm wide.
1. Cells with high energy demands, such as muscle fibres, active-transport epithelia, and sperm cells, contain thousands of mitochondria, while less active cells have fewer.

Outer Membrane: Controlling Entry

The outer membrane is smooth and contains large channel proteins called porins.
1. Porins let small molecules (pyruvate, oxygen, CO2, ADP, ATP) pass freely between the cytoplasm and the intermembrane space.
2. Larger molecules and proteins cannot cross without specific transport.

Common Mistake

The outer membrane is not where oxidative phosphorylation occurs.
The outer membrane's job is to contain the organelle and control what enters.
The inner membrane is where the electron transport chain and ATP synthase sit.

Inner Membrane and Cristae: The Site of Oxidative Phosphorylation

The inner membrane is folded into structures called cristae (singular: crista).
1. These folds massively increase the surface area for the electron transport chain (ETC) and ATP synthase.
2. More cristae means more surface area, which means more ATP production.
3. Cells with very high energy demands, like cardiac muscle cells, have mitochondria with densely packed cristae.

Nice try, unfortunately this paywall isn't as easy to bypass as you think. Want to help devleop the site? Join the team at https://revisiondojo.com/join-us. exercitation voluptate cillum ullamco excepteur sint officia do tempor Lorem irure minim Lorem elit id voluptate reprehenderit voluptate laboris in nostrud qui non Lorem nostrud laborum culpa sit occaecat reprehenderit

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

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 nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

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

Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit.

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 nisi ut aliquip ex ea commodo consequat.

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.

Unlock the rest of this chapter with a free account

The Mitochondrion: Where Aerobic Respiration Happens

The mitochondrion is a double-membrane organelle found in nearly all eukaryotic cells.
It is the site of aerobic cell respiration, the reactions that transfer energy from organic molecules to ATP.
1. Every structural feature of the mitochondrion relates directly to this function.
Mitochondria are typically sausage-shaped, roughly 1 to 5 µm long and 0.5 to 1 µm wide.
1. Cells with high energy demands, such as muscle fibres, active-transport epithelia, and sperm cells, contain thousands of mitochondria, while less active cells have fewer.

Outer Membrane: Controlling Entry

The outer membrane is smooth and contains large channel proteins called porins.
1. Porins let small molecules (pyruvate, oxygen, CO2, ADP, ATP) pass freely between the cytoplasm and the intermembrane space.
2. Larger molecules and proteins cannot cross without specific transport.

Common Mistake

The outer membrane is not where oxidative phosphorylation occurs.
The outer membrane's job is to contain the organelle and control what enters.
The inner membrane is where the electron transport chain and ATP synthase sit.

Inner Membrane and Cristae: The Site of Oxidative Phosphorylation

The inner membrane is folded into structures called cristae (singular: crista).
1. These folds massively increase the surface area for the electron transport chain (ETC) and ATP synthase.
2. More cristae means more surface area, which means more ATP production.
3. Cells with very high energy demands, like cardiac muscle cells, have mitochondria with densely packed cristae.

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 B2.2.4: Adaptations of the Mitochondrion for Production of ATP by Aerobic Cell Respiration Notes

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

The Mitochondrion: Where Aerobic Respiration Happens

Outer Membrane: Controlling Entry

Inner Membrane and Cristae: The Site of Oxidative Phosphorylation

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

The Mitochondrion: Where Aerobic Respiration Happens

Outer Membrane: Controlling Entry

Inner Membrane and Cristae: The Site of Oxidative Phosphorylation

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