The study of chemistry within the scope of biology: the compounds that occur and the reactions involving them in living organisms.

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104 views

What's the difference between Cytoplasmic pool and Granular storage pool?

What's the difference between Cytoplasmic pool and Granular storage pool when speaking about neurotransmitters and synaptic cleft. I encountered this here: Amphetamine’s mechanism of action thus ...
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1answer
118 views

Molecules and human memory

Has it been demonstrated that the memory of human brain is just connections between neurons, not "long" molecules such as RNA or proteins?
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1answer
5k views

Is there a difference between NADH and NADH2?

I've been reading a lot about the oxidative dissimilation etc, and often I see different sources use NADH and NADH2 in the same reactions. One source uses NADH and another uses NADH2 in the exact same ...
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1answer
174 views

Raphide toxicity in Pothos plant

Recently I found out that the common houseplant Pothos (Epipremnum aureum) is toxic to cats and dogs due to the presence of "insoluble raphides." I have a lot of these plants around my house and my ...
7
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1answer
355 views

What biological processes cause leaves to change colours in Autumn?

I am curious to learn what are the biological mechanisms that cause leaves of deciduous plants to change colour? What happens to the chlorophyll? What environmental phenomena (temperature/air ...
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1answer
506 views

Water potential in plants?

The concept of water potential in plants tries (and succeeds) to explain various movement and transports in plants. I have learnt that it can be though of being composed of various components like the ...
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3answers
126 views

Are there any methods to quantify H2O2 (hydrogen peroxide) which don't rely on horseradish peroxidase?

I can't use HRP since my substrates interfere with it and I need a real-time method because I want to measure kinetic parameters of some oxidases.
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3answers
1k views

Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am ...
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1answer
151 views

Why not produce protein based on condensation reaction?

I'm fairly new learning about protein. As I know protein can be synthesis by condensation reaction. And the current method to produce protein is purify them from an organism. So why not produce ...
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1answer
173 views

Cloning two fluorescent proteins with different promoters in the same plasmid?

I want to clone two fluorescent proteins both driven by different promoters in a plasmid to be used to transform B. subtilis at the amyE locus. For this I want to use plasmid pSG1729 (Lewis and ...
4
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2answers
297 views

Are there dangers to Teflon and aluminium cookware?

I've been reading some articles on the internet about dangers of Teflon and aluminium to the body. My family say I'm just exaggerating the situation, and maybe I am, though I'm not sure because not ...
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1answer
61 views

Isoprenoid Diphosphate Concentration in Yeast saccharomyces cerevisiae

Isoprenoid Diphosphate(IPP) is an important metabolites which is precursor in lot of secondary metabolites like Dolichol diphosphate, ubiquinone, prenylated proteins and carotenoid (not synthesized ...
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2answers
128 views

Finding a easy and cheap method for dyeing dNTP

I want to measure OD to know the concentration of dNTP. Any idea for dyeing dNTP at cheapest price and easiest way ?
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2answers
131 views

Is Hydrogen gas present in biogas, and does it spontaneously ignite?

Is Hydrogen gas present in biogas? As it is highly inflammable, may it ignite the other gases like methane?
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0answers
173 views

Can Pfx polymerase add only one 3' A overhang?

I am trying to clone a PCR product that was amplified using Pfx polymerase into pGemT vector. I had to A-tail the PCR product using Taq polymerase since Pfx only generates blunt end products. My ...
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1answer
61 views

Some question about materials for PCR

I'm planning to order oligo, polymerase, nucleotide, buffer for my first diy PCR experiment (now I have nothing), so I have some questions. How and how long I can storage them? I have only a fridge ...
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1answer
57 views

Carotenoid biosynthesis in yeast

Does Budding Yeast Sacchromyces cerevisiae produces significant amount of carotenoids? Have anybody estimated the ratio of flux going in branches 1. Cholesterol synthesis(via squalene) 2. Coenzyme Q6 ...
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2answers
206 views

Can PCR tubes be made of different materials than plastic?

Does it matter if I replace the PCR tube (usually made of plastic) with another material like aluminum, glass, or something similar?
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2answers
240 views

Can a dNTP be built into a RNA strand?

DNA consists of deoxyribonucleotides, RNA consists of ribonucleotides. They differ mainly (apart from the uracil / thymine difference) in the sugar part, the deoxyribose and the ribose. Those two ...
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3answers
132 views

Finding a template/oligo combination for my first PCR experiment

I'm an information technology engineer. I love biology so I research biological topics and have an interest in PCR. That's why I have decided to create a PCR machine. Everything is done now and I ...
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2answers
329 views

Does osmosis occur when we have two different substances?

Assume that we have a semi-permeable membrane with water on both sides. First, straightforward, case: On the right side, we have a concentration of the substance A, and on the left side, we have pure ...
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2answers
407 views

Why are enzyme-catalysed reactions slower at lower substrate concentration?

Suppose I'm using 200 nmoles of enzyme and 2 mmoles of substrate. The enzyme should be saturated but if I use 50 mmoles of substrate, the reaction will be faster. Why? I just can't get it! Even at ...
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1answer
149 views

How do you remove DNA/RNA from plastics?

I want to know how to make plastic containers free of DNA & RNA? this is just for knowledge
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0answers
60 views

When a Lysosome's bonding sites all get bonded to, what is the most resource and energy efficient way to handle the used Lysosome?

Let's say a Lysosome that bonds to a hazardous material to neutralize it has all bonding sites used up. would it be more safe / efficient to excrete the entire Lysosome / hazardous material molecule ...
4
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1answer
52 views

How different are tissue-specific fibroblasts from each other?

I am planning to utilize a new system in our lab, in which I will co-culture cancer cells from different tissues with fibroblasts. I have the option to receive skin-derived primary fibroblasts. I ...
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1answer
887 views

Why is allolactose the LacI inducer?

For what reason(s) is allolactose, instead of lactose, the "natural" inducer of lac operon repressor?
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2answers
77 views

What nutritious insects exist to farm that require the least attention?

What nutritious insects exist to farm that require the least attention? I'm looking to automate simply, in a self regulating way. Edit: To add detail, I imagine the insects would live densely in a ...
4
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1answer
589 views

Why is funnel web spider venom so lethal to humans and not so much for other mammals?

According to the information from this article, People and other primates are exquisitely sensitive to funnel web venom but, intriguingly, other mammals such as mice, rabbits, guineapigs, dogs ...
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1answer
105 views

Electron transport in granal stacks

See paper for distribution of PS-I and PS-II within grana As explained in the above paper, the PS-I complex is primarily located within non-appressed thylakoid region and stroma lamella, while PS-II ...
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1answer
88 views

Photosynthesis regulation

I read about the regulation of Calvin cycle by thioredoxin which activates key enzymes essentially by converting disulphide linkages on inactive enzymes into sulfhydryls. Another regulatory mechanism ...
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2answers
5k views

Can the excessive consumption of mineral water lead to kidney stones or other health issues?

I heard that drinking too much mineral (bottled) water could lead to problems such as kidney stones because of the high amount of minerals in it. Is it true? If so, what is considered to be excessive? ...
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1answer
64 views

Breaking of fats

There is a question I encountered. Why is fat harder to digest ? A) It has ester bonds. B) It is not easily soluble in water. Which is the most appropriate answer?
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1answer
65 views

Do Acyl Carrier Proteins and Conenzyme A have similar reactivity?

In terms of the reactions they undergo are they roughly equivalent groups?
2
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1answer
41 views

Are CoA and CoAS the same thing in a compound?

Is CoA-S-R the same as CoA-R, and is CH3C(=O)CoA the same as CH3C(=O)SCoA? Eg. Above is the compound on the right just coenzyme A or is it actually another compound and not just notation?
7
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1answer
71 views

Excretion of monovalent and divalent ions in sharks

I have heard that sharks excrete $\ce{Na+}$ and $\ce{Cl-}$ by their gill surfaces but divalent ions like magnesium are excreted through feces. What could be the reason behind this?
2
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1answer
126 views

Does precipitation influence the UV spec reading?

I have been checking my sample for Hydroxyl radical scavenging activity. I have dissolved Hydrogen peroxide in Phosphate buffer. My sample is clear and reagent is also clear but when I have mixed my ...
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1answer
475 views

Amino acid characteristics that determine their chemical properties?

What chemical aspect of amino acids results in their having different properties such that the chemical and physical properties of polypeptides vary with both amino acid content and amino acid order? ...
2
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1answer
53 views

What does “rapamycin-sensitive oncogenic transformation” mean?

Can someone explain exactly what "rapamycin-sensitive oncogenic transformation" is? I get that it's a drug that suppresses the immune system but what does it have to do with oncogenic transformation? ...
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3answers
607 views

Why do neurones use chemical signalling at synaptic junctions?

Problem. When a neurone fires, it sends an electrical signal that jumps down the axon via the nodes of Ranvier very rapidly. At a synaptic junction, chemical brownian diffusion signalling with ...
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0answers
126 views

How do cells slowly degrade 5,5'-dibromo-4,4'-dichloro-indigo?

5,5'-dibromo-4,4'-dichloro-indigo is the product of X-gal cleavage, often used as a reporter with B-galactosidase. I've made the (unreferenced) observation that it seems as though the blue product ...
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3answers
1k views

Histidine aromaticity

I understand that the imidazole ring in histidine is aromatic. I also realize that it retains it's aromaticity when protonated. I am wondering why it is not mentioned at all in basic text books such ...
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1answer
213 views

What is the use of futile reaction cycling such as Fruc-P to Fruc-BP?

One rate-limiting step of glycolysis is the conversion of Fructose-Phosphate (Fruc-P) to Fructose-Bisphosphate (Fruc-BP), catalysed by Phosphofructokinase (PFK). The reaction involves hydrolysing one ...
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2answers
356 views

PEG-silane treatment: why incubate for 18 hours at 60 degrees Celsius?

I am conducting a biochemistry-related experiment and I have been unable to understand a step which is commonly performed. My aim in this step is to apply a PEG (Polyethylene glycol) silane layer. ...
2
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3answers
740 views

Michaelis-Menten Kinetics: Does measuring apparent Km and Vmax take into account competing reactions?

I am learning about why it is important to measure Km and Vmax for each experimental setup because measuring the "apparent" Km and Vmax includes enzyme inhibitions of which one might not be aware. ...
3
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1answer
171 views

What molecular processes are involved in pseudopodial extension?

I am curious as to the processes and mechanisms involved in the extension of pseudopodia in amoeba. How does the cell know and control the direction and extent of pseudopodia formation at a molecular ...
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0answers
93 views

How do omega-3 fatty acids reduce cholesterol at the molecular level?

I have heard that omega-3 fatty acids found in fish are a good way to prevent/reduce cholesterol problems. My question is how do omega-3 fatty acids do that: what are they doing on a chemical level ...
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3answers
113 views

What biochemical molecule viewer allows for changes in amino acids and resulting tertiary structure?

I am familiar with the Jmol, Rasmol and PyMoL softwares, and was recently introduced to BioBlender. However, I am completely unaware if any of these programs (or others) are capable of loading a .pdb ...
3
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1answer
81 views

What is the translation termination efficiency in mammalian cells?

When I express proteins in bacteria I put at least two stop codons at the end of the gene to increase the termination efficiency. Is this the case in eukaryotic cells too? If I put a single stop codon ...
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3answers
13k views

Differences Between Protein Motifs and Protein Domains?

I am in a 300-level molecular biology class and am unclear about this concept and how to delineate motifs versus domains of proteins. Any suggestions would be much obliged.
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1answer
126 views

How do you store membrane proteins?

We're producing some membrane proteins and they aren't amenable to freeze thaws even when we add glycerol. The proteins are solubilized in detergent above the cmc so they should be in micelle form in ...