IB Biology Topic C1.1.12 Generation of Heat Energy by the Reactions of Metabolism Revision Notes (HL)

IB Biology Topic C1.1.12 Generation of Heat Energy by the Reactions of Metabolism Revision Notes (HL) | RevisionDojo

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Metabolism Always Releases Some Energy as Heat

Metabolism is the sum of all chemical reactions in a living organism, and it transforms energy from one form to another.
No energy transfer is ever 100% efficient, so some energy is always released as heat.

Definition

Metabolism

The sum of all chemical reactions occurring in an organism to maintain life, including reactions that break down molecules for energy (catabolism) and reactions that build molecules for growth and repair (anabolism).

Catabolic Reactions Are the Main Source of Heat

Catabolic reactions break large molecules into smaller ones and release energy, so they are exergonic.
Some of the released energy is captured in ATP, but a large share is released as heat.
The many reactions of cellular respiration run constantly in every cell, so heat is generated all the time across the body.

Example

When glucose is oxidised in respiration, only part of its energy is captured as ATP.
Much of the rest is released as heat, which warms the organism.

Anabolic Reactions Release Less Heat

Anabolic reactions build large molecules and take in energy, so they are endergonic.
They still release a little heat because no energy transfer is fully efficient, but far less than catabolic reactions do.

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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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Metabolism Always Releases Some Energy as Heat

Metabolism is the sum of all chemical reactions in a living organism, and it transforms energy from one form to another.
No energy transfer is ever 100% efficient, so some energy is always released as heat.

Definition

Metabolism

Catabolic Reactions Are the Main Source of Heat

Catabolic reactions break large molecules into smaller ones and release energy, so they are exergonic.
Some of the released energy is captured in ATP, but a large share is released as heat.
The many reactions of cellular respiration run constantly in every cell, so heat is generated all the time across the body.

Example

When glucose is oxidised in respiration, only part of its energy is captured as ATP.
Much of the rest is released as heat, which warms the organism.

Anabolic Reactions Release Less Heat

Anabolic reactions build large molecules and take in energy, so they are endergonic.
They still release a little heat because no energy transfer is fully efficient, but far less than catabolic reactions do.

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 C1.1.12: Generation of Heat Energy by the Reactions of Metabolism Notes

Metabolism Always Releases Some Energy as Heat

Catabolic Reactions Are the Main Source of Heat

Anabolic Reactions Release Less Heat

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

Metabolism Always Releases Some Energy as Heat

Catabolic Reactions Are the Main Source of Heat

Anabolic Reactions Release Less Heat

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