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1. Introduction to biochemistry
- Prof. Gerald W. Feigenson
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2. Amino acids and peptides
- Prof. Gerald W. Feigenson
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3. Protein structure principles
- Prof. Gerald W. Feigenson
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4. Observed protein structures
- Prof. Gerald W. Feigenson
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5. Protein folds and IV structure
- Prof. Gerald W. Feigenson
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6. Protein stability and folding
- Prof. Gerald W. Feigenson
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7. Haemoglobin structure and stability
- Prof. Gerald W. Feigenson
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8. Enzyme specificity and catalysis
- Prof. Gerald W. Feigenson
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9. Enzyme kinetics (Michaelis-Menten)
- Prof. Gerald W. Feigenson
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10. Enzyme inhibition; chymotrypsin
- Prof. Gerald W. Feigenson
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11. Enzyme regulation and coenzymes
- Prof. Gerald W. Feigenson
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12. Lipids, biomembranes and membrane proteins
- Prof. Gerald W. Feigenson
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13. Structure and function of carbohydrates
- Prof. Gerald W. Feigenson
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14. Metabolism principles
- Prof. Gerald W. Feigenson
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15. Glycolysis - energy and useful cell chemicals
- Prof. Gerald W. Feigenson
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16. Glycolysis control
- Prof. Gerald W. Feigenson
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17. Metabolism of pyruvate and fat
- Prof. Gerald W. Feigenson
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18. Urea cycle; oxidative phosphorylation 1
- Prof. Gerald W. Feigenson
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19. Urea cycle; oxidative phosphorylation 2
- Prof. Gerald W. Feigenson
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20. Light-driven reactions in photosynthesis
- Prof. Gerald W. Feigenson
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21. Gluconeogenesis and the Calvin cycle
- Prof. Gerald W. Feigenson
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22. Synthesis of lipids and N-containing molecules 1
- Prof. Gerald W. Feigenson
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23. Synthesis of lipids and N-containing molecules 2
- Prof. Gerald W. Feigenson
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24. Hormone mechanisms
- Prof. Gerald W. Feigenson
Printable Handouts
Navigable Slide Index
- Introduction
- Lecture outline
- Activation' of molecules for further reaction
- Cholesterol biosynthesis
- Lipoproteins deliver lipids to tissues
- Normal, healthy uptake of LDL from blood to cells
- Pathology: artery blocked; clot formed
- Nitrogen (gas fixing)
- Nitrogen reducing reactions
- How NH4+ gets into other biomolecules
- Many 'cell chemicals' come from glucose
- Synthesis of other amino acids
- Amino acids as biosynthetic precursors
- N-containing molecules from amino acids
- Control of all metabolism
- Lecture summary
Topics Covered
- Summary of ‘activated’ molecules
- Cholesterol biosynthesis
- Lipoproteins and their roles
- Synthesis of N-containing molecules
- Control of all metabolism
Talk Citation
Feigenson, G.W. (2022, November 27). Synthesis of lipids and N-containing molecules 2 [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved August 31, 2024, from https://doi.org/10.69645/DYXB2202.Export Citation (RIS)
Publication History
Financial Disclosures
- Gerald Feigenson has no commercial/financial relationships to disclose.
Synthesis of lipids and N-containing molecules 2
Request access to the Principles of Biochemistry lecture series, an extensive introductory to the field of biochemistry. An HSTalks representative will contact you with more information about this series and getting unrestricted access to it.
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Transcript
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0:00
Greetings. Welcome to this Principles of Biochemistry lecture series.
I am Jerry Feigenson,
professor in the Department of
Molecular Biology and Genetics at Cornell University in the USA.
This is the second part of Lecture 21.
In the first part, you learned about synthesis of
fatty acids and of the more complex phospholipids and fats.
0:27
In this second part of this lecture,
we study how cholesterol is synthesized,
and how it is delivered to cells,
and what can go wrong with that delivery.
Then we examine how nitrogen becomes a component of
biomolecules such as amino acids and heme groups.
But first, a brief digression to make more clear a principle of metabolism,
what we call activation of molecules.
0:59
Now, I've been talking about activation of molecules or making them chemically reactive.
Let me summarize what we've seen so far.
In fatty acid Beta oxidation, several lectures ago,
you saw that the cell first synthesizes
the AMP ester and then the CoA thioester of the fatty acid.
So those are unstable,
they're going to chemically react. And we just briefly talked about this,
glucose for glycogen formation,
it reacts with the nucleotide UTP to make UDP glucose which is unstable.
And we just saw this one,
the carbonate that adds to acetyl-CoA,
that carbonate has to be made unstable as phosphocarbonate.
And for fatty acid formation, we saw malonyl-CoA.
Malonyl-CoA has a key role,
it's unstable, it's chemically reactive.
And we just saw fatty acid for synthesis of fat or phospholipid,
the fatty acids have to be made unstable.
They form the CoA thioester.
Then phosphatidic acid or phospholipid headgroups are made
unstable, as the CDP-diacylglycerol or the CDP headgroup.
So those are unstable.
And this one which we will see in just a moment for cholesterol synthesis,
isoprenes are activated as the pyrophosphate derivative.
They are now unstable.
So what's going on here?
Why are these unstable molecules being synthesized?
The reason is actually very straight forward.
The activated molecules are now unstable and that
means that the next reactions become thermodynamically favorable.
So we see this activation of molecules happening throughout metabolism.
That's why we can say that reactions for biosynthesis are
favorable, and reactions for breakdown of molecules are favorable.
This involves activation of molecules.