Protein Synthesis: Is it a Vicious Circle?

[avito009]

Is Protein Synthesis a vicious circle?

When we take proteins they are converted to amino acids. But during protein synthesis amino acids are converted to proteins. Is this correct and in a sense its a vicious circle.

 

[adjacent]

What do you mean by "When we take proteins they are converted to amino acids."?

Protein synthesis does not convert proteins to amino acids.

 

[avito009]

I mean when we eat foods that contain protein, that protein gets converted to amino acids. And during protein synthesis amino acids get converted to proteins. So isn't that a vicious circle. Protein gets converted to protein.

 

[Ryan_m_b]

No it isn't, I don't think the term means what you think it means:

vi·cious cir·cle

noun

1. A sequence of reciprocal cause and effect in which two or more elements intensify and aggravate each other, leading inexorably to a worsening of the situation.

synonyms: dilemma, vicious cycle, downward spiral, vortex, no-win situation, catch-22, chicken-and-egg situation

"but if I bring Mr. Raines the foods he asks for, he blames me for not serving healthier meals—it's a vicious circle"

Having to ingest more proteins to replace those used is just another example of metabolism.

 

[atyy]

I mean when we eat foods that contain protein, that protein gets converted to amino acids. And during protein synthesis amino acids get converted to proteins.

Yes.

So isn't that a vicious circle.

In science, you can call things anything you want like F=ma is the same as G=pq, but I agree with Ryan_m_b that this is an unusual use of "vicious circle".

 

[DiracPool]

When we take proteins they are converted to amino acids. But during protein synthesis amino acids are converted to proteins. Is this correct and in a sense its a vicious circle.

Why not just consider it a form of recycling? You're disassembling a structure of elements in one form and re-assembling them in a different form that may be more useful. You wouldn't consider that cycle "vicious" would you. I would say it's more pragmatic than vicious.

 

[Ygggdrasil]

The term that is more often used in biology is a "futile cycle" – the situation where a molecule is synthesized by one metabolic pathway only to be broken down into its components by another pathway. Very often, biology has evolved mechanisms to avoid futile cycling, for example, the signaling pathways that prevent glycolysis (which breaks down glucose) and gluconeogenesis (which synthesizes glucose), from occurring at the same time.

Sometimes futile cycling, however, has important regulatory roles. For example, the phosphorylation of proteins is an important regulatory mechanism for turning many biological processes on or off. Protein kinases will attach phosphate groups to proteins while phosphatases will remove these phosphate groups. The constant cycling between phosphorylated and unphosphorylated states mediated by the kinases and phosphatases is a very rapid and dynamic process, allowing the cell to rapidly change the phosphorylation state of its target proteins by altering the balance of activity between specific kinases and phosphatases.

Similar regulation sometimes occurs in protein synthesis, most notably for many proteins involved in the cell cycle. These proteins can be targeted for degradation by the attachment of a ubiquitin tag, and this degradation is important for regulating the levels of these proteins in the cell.