Questions tagged [biosynthesis]

Biosynthesis is the process in which living organism synthesize molecules and substances they need. Examples would be the photosynthesis where in the end glucose is synthesized or melanin as the result of the melanin biosynthesis.

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8
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2answers
617 views

Why do fully grown organisms need protein intake?

If proteins are building blocks of an organism then it makes sense why a growing organism would need an intake of them, but why would a fully grown organism need proteins (aside from those lost by ...
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3answers
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Nicotine levels in non fruit/edible parts of plants (that are not tobacco)

I am an ex smoker who now vapes (uses e-cigs). Various authorities are equating vaping with smoking by calling it a 'tobacco product' - which is in a sense true given that the majority of nicotine ...
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1answer
8k views

Location of nucleotide synthesis and transport

I couldn't find this question directly asked so I thought I would ask it In Fundamentals of Biochemistry 3e (Voet et al), it has a small small little comment about pyrimidine synthesis: (In a diagram ...
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5answers
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How much nucleoside triphosphate is required to form one peptide bond during protein synthesis?

I'm trying to find out how many molecules of nucleoside triphosphates (ATP, GTP, UTP and/or CTP) it takes to release enough energy to link two amino acid monomers together with a peptide bond, ...
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In ketogenesis, why is acetacetyl-CoA not directly hydrolized to acetoacetate in ketogenesis?

Ketogenesis pathway maps show acetoacetyl-CoA converted to HMG-CoA and only then to the first ketone body acetoacetate. Why this detour instead of directly hydrolyzing off the CoA to get there in a ...
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1answer
50 views

Are all/most/any membranes comprised of lipids from the smooth ER?

I'm attending an introductory high school course to cell biology. Based on my understanding, lipids – the building blocks of membranes – are formed in the smooth ER. Are all/most/any membranes ...
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1answer
92 views

How can cane sugar sucrose be different from beet sugar in regard to carbon-13 content?

According to an article in SCIENZA IN CUCINA, by Dario Bressanini, le Scienze Blog content of $^{13}C$ differs in sucrose in beet sugar compared to cane sugar. What is this due to? Are there any ...
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2answers
187 views

Nomenclature of enzymes involved in synthesis of glutamine

I am considering nitrogen fixation and in my lecture notes, there is the statement The glutamine synthetase- glutamate synthase system requires use of an ATP molecule as well as reducing power. ...
3
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1answer
1k views

Relative roles of ATP and NADPH in anabolic and other processes

Chemistry isn’t my strong point, but I’m trying to understand why NADPH is said to be the main agent necessary for anabolic reactions, and if NADPH is used for anabolic reactions what is ATP used for? ...
3
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0answers
74 views

Regulation of the concentration of precursors of DNA and RNA synthesis

What is the specific cellular process for regulating the amount of the four DNA bases (adenine, thymine, cytosine, and guanine) that are present in the cytoplasm of a cell? Basically, how do the cell'...
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111 views

Can the Human body Synthesise Vitamin D from Phytosterols?

I know that the human body can synthesise vitamin D from cholesterol, but can it do so from phytosterols?
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1answer
2k views

Why are fatty acids consisting of even number of carbons predominant?

Most of the fatty acids in animal biology consist of even number of carbons in its parent chain. What property of such fatty acids cause the biological systems to prefer them over the odd counterparts?...
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1answer
100 views

How essential is vitamin B3 to the diet?

I know this might seem contradictory since by definition a vitamin is an essential part of the diet but I have read that nicotinamide, a form of vitamin B3, can be synthesised from L-tryptophan. Is it ...
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1answer
52 views

Difference between AjuA and ajuA in biosynthesis

I cannot for the life of me figure this out. In the following figure, you can find ajuA and AjuA for example. I do understand that the lower-case ones are the genes. The arrows indicate the direction ...
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2answers
126 views

Determine whether aromatics originate from polyketide or shikimate pathway

Is there a way to determine whether an aromatic compound originates from the polyketide or shikimate pathway by looking at its structure? If so, how?
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1answer
610 views

Which mammals cannot synthesize taurine?

It is fairly common knowledge that domesticated cats cannot synthesize the compound taurine. Other mammals seem to be able to synthesize taurine from cysteine [source]. Are there other mammals that ...
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1answer
51 views

does life make or break?

Ok, this question seems like it may be impossible to answer, but would be interesting to see if anyone has an idea. Throughout the course of a human life, do we make more molecular bonds than we ...
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1answer
215 views

Dehydration Synthesis: Why does a monomer contribute a -H instead of an H atom?

My Campbell's Biology 9th edition textbook says that a dehydration synthesis is a reaction in which water is produced while two monomers are joined together. Specifically, it makes the following ...
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0answers
61 views

What medium is the bacteria used to synthesize B12 sourced from?

Would that be from water, soil, plants, funguses,...? I asked the question in Quora but that, at the time of posting in this forum, haven't been very helpful. I also have searched for the ...
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0answers
47 views

Calculation of NADPH molecules number needed to reduce a substrate in enzymatic reaction

I am inquiring if it is just simply possible - as it seems to be - to calculate the number of NADPH molecules needed by an enzyme (let say for example Dihydrofolate Reductase DHFR) to reduce the ...
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1answer
4k views

What is the role pyruvate carboxylase in lipogenesis?

I just know that Acetyl-CoA is a positive allosteric modulator for pyruvate carboxylase, but I cannot find anything else.
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1answer
250 views

A molecular marker for global protein synthesis

I know that protein synthesis is governed by a lot of factors (I'm mostly studying the mTOR pathway), but I'm looking for some kind of marker that will indicate the global protein synthesis rates. I ...
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1answer
3k views

What is the difference between gene expression and protein synthesis? [closed]

I have no idea what I'm supposed to do. Can someone please help me? What is the difference between gene expression and protein synthesis?
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1answer
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Protoporphyrinogen (IX) formation in heme synthesis

This picture shows one of the steps of heme synthesis. In this step two propanoate groups of coproporphyrinogen III are decarboxylated to form protoporphyrinogen IX. The enzyme that catalyses this ...
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how long would oxidation of ammonia solution to nitrates take?

A hot topic among amateur chemists is making nitric acid from ammonia. While not as useful, im interested in making nitrate salts from ammonia as well. A simple idea is to just infect ammonia solution ...
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If calcium ions and cholesterols are found on the surface of the skin, would it be possible for Vitamin D to be synthesised on the skin?

Calcium ions are abundantly found in the extracellular space of the stratum corneum area, the top most layer of the skin (Skin Barrier and Calcium; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5929942/...
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How many proteins do all human ribosomes together produce per hour? [closed]

Very roughly how many proteins (chains) are synthesized in the human body per hour under normal conditions? (And how many ribosomes does the human body have?)
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Essential amino acids

Humans and the majority of animal species cannot synthesize essential amino acids (Info: Campbell biology 9th edition). However, meat, eggs, et cetera provide all required essential amino acids. And ...