An Introduction to Metabolism

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Slide 1

The Energy of Life

The living cell is a miniature chemical factory where thousands of reactions occur

The cell extracts energy and applies energy to perform work

Some organisms even convert energy to light, as in bioluminescence

Slide 2

Fig. 8-1

Slide 3

Concept 8.1: An organism’s metabolism transforms matter and energy, subject to the laws of thermodynamics

Metabolism is the totality of an organism’s chemical reactions

Metabolism is an emergent property of life that arises from interactions between molecules within the cell

Slide 4

Organization of the Chemistry of Life into Metabolic Pathways

A metabolic pathway begins with a specific molecule and ends with a product

Each step is catalyzed by a specific enzyme

Slide 5

Fig. 8-UN1

Enzyme 1

Enzyme 2

Enzyme 3

D

C

B

A

Reaction 1

Reaction 3

Reaction 2

Starting

molecule

Product

Slide 6

Catabolic pathways release energy by breaking down complex molecules into simpler compounds

Cellular respiration, the breakdown of glucose in the presence of oxygen, is an example of a pathway of catabolism

Slide 7

Anabolic pathways consume energy to build complex molecules from simpler ones

The synthesis of protein from amino acids is an example of anabolism

Bioenergetics is the study of how organisms manage their energy resources

Slide 8

Forms of Energy

Energy is the capacity to cause change

Energy exists in various forms, some of which can perform work

Slide 9

Kinetic energy is energy associated with motion

Heat (thermal energy) is kinetic energy associated with random movement of atoms or molecules

Potential energy is energy that matter possesses because of its location or structure

Chemical energy is potential energy available for release in a chemical reaction

Energy can be converted from one form to another

Animation: Energy Concepts

Slide 10

Fig. 8-2

Climbing up converts the kinetic

energy of muscle movement