1887

Chapter 6 : Cell Metabolism

MyBook is a cheap paperback edition of the original book and will be sold at uniform, low price.

Ebook: Choose a downloadable PDF or ePub file. Chapter is a downloadable PDF file. File must be downloaded within 48 hours of purchase

Buy this Chapter
Digital (?) $30.00

Preview this chapter:
Zoom in
Zoomout

Cell Metabolism, Page 1 of 2

| /docserver/preview/fulltext/10.1128/9781555816094/9781555813048_Chap06-1.gif /docserver/preview/fulltext/10.1128/9781555816094/9781555813048_Chap06-2.gif

Abstract:

This chapter discusses how food is converted to energy for cells and how cells use that energy to make molecules they need. Metabolic pathways are very often branched because there is more than one possible fate for an intermediate in the pathway. For example, the pathway that cells use to break down fats to get energy converges with the metabolic pathway for breaking down glucose to get energy. In the electron transport pathway, the energy released during the step-by-step breakdown of carbohydrates, lipids, and proteins is harvested from various temporary storage molecules to make adenosine triphosphate (ATP) by attaching a phosphate group to adenosine diphosphate (ADP). ATP thus serves as a sort of energy currency for the cell--it is created during the energy-yielding processes of catabolism and spent in the energy-requiring processes of anabolism. One of the simplest examples of feedback inhibition in metabolism is the pathway for synthesis of the amino acid isoleucine. Comparing the fates of people with enzyme defects at different points in the phenylalanine catabolism pathway resulting in either phenylketonuria (PKU) or alkaptonuria illustrates an important point. Studies of Gaucher’s disease patients have revealed that many different mutations in the gene for the lipid-degrading enzyme can cause the disease.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6

Key Concept Ranking

Acetyl Coenzyme A
0.50342464
Electron Transport System
0.4664876
Amino Acid Synthesis
0.40492448
0.50342464
Highlighted Text: Show | Hide
Loading full text...

Full text loading...

Figures

Image of Figure 6.1
Figure 6.1

Cellular processes are carried out by a sequence of enzymes, each of whichpromotes a specific reaction with a specific substrate, rather like a robot in an assemblyline.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.2
Figure 6.2

A branching metabolic pathway.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.3
Figure 6.3

If one enzyme in a multistep process is missing or fails to function, the intermediate synthesized in the previous step may build up, and the end product cannot be made.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.4
Figure 6.4

Burning gasoline breaks the C-H and C-C bonds in gasoline to produce CO, H, and lots of energy.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.5
Figure 6.5

Energy balance in chemical reactions. If the chemical bonds in the product(s) contain more energy than the bonds in the reactants, energy is consumed in the reaction. In the opposite situation, energy will be released in the reaction.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.6
Figure 6.6

Catabolism in animals.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Untitled
Untitled

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.7
Figure 6.7

Breakdown pathways for sugars, amino acids, and fatty acids converge. TCA, tricarboxylic acid.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.8
Figure 6.8

ATP is the cell's major energy storage molecule. It is synthesized from ADP and a phosphate group, with a large energy input. Breaking ATP down into ADP plus phosphate releases the energy.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.9
Figure 6.9

Many intermediates of glucose breakdown can be used as starting materials in the synthesis of other molecules.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.10
Figure 6.10

Energy released during the breakdown of food (catabolism) is stored in ATP. ATP is then broken down, releasing its stored energy, to power biosynthesis of cellular components (anabolism).

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.11
Figure 6.11

Enzyme inhibition.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.12
Figure 6.12

A simple example of feedback inhibition. When isoleucine is plentiful, it blocks its own biosynthesis by inhibiting enzyme 1.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.13
Figure 6.13

Feedback inhibition at metabolic branch points.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.14
Figure 6.14

Feedback inhibition within a network of pathways

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.15
Figure 6.15

Regulation of tryptophan biosynthesis genes. P is the promoter of the genes.O is the repressor binding site. Little tryptophan in cell.The repressor does not bind to target DNA. genes are transcribed. Plentiful tryptophan in cell.Tryptophan repressor complex binds to DNA and prevents the transcription of genes.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.16
Figure 6.16

Phenylalanine is normally converted to tyrosine by the enzyme PAH. If PAH is not present, phenylalanine is converted to phenylketones, resulting in the condition phenylketonuria.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.17
Figure 6.17

Potential disruptions inphenylalanine and tyrosine metabolism.The arrows represent from one to manymetabolic steps.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.18
Figure 6.18

Useful products of glucose breakdown provided by various microbes.

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint
Image of Figure 6.19
Figure 6.19

Environmental Protection Agency personnel monitor an oil spill bioremediationtest site. (Photograph courtesy of Albert Venosa, Environmental Protection Agency.)

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Permissions and Reprints Request Permissions
Download as Powerpoint

References

/content/book/10.1128/9781555816094.chap6

Tables

Generic image for table
Table 6.1

Chemcials currently produced by microbial metabolism of glucose and their industrial applications

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6
Generic image for table
Table 6.2

Useful products from microbial metabolic pathways other than glucose metabolism

Citation: Kreuzer H, Massey A. 2005. Cell Metabolism, p 111-136. In Biology and Biotechnology. ASM Press, Washington, DC. doi: 10.1128/9781555816094.ch6

This is a required field
Please enter a valid email address
Please check the format of the address you have entered.
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error