Tagged Questions

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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2
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1answer
216 views

How to calculate or know by experiment the entropy of enzymes or protein?

How do you calculate or experimentally determine the entropy of enzymes or protein? In particular, I am interested in Boltzmann and conformational entropy, and Gibbs free energy. Any references are ...
3
votes
1answer
232 views

Can replication occur if DNA is methylated?

Can a methylated strand of DNA be replicated without removing methylation? Does it make any difference if the strand is methylated or not (during replication)?
-4
votes
4answers
166 views

Are biological systems engineered? They are often reverse engineered at a molecular level!!

Understanding biological systems, molecular biologists need to “reverse engineer” them. Is this evidence that the systems were engineered to begin with?
2
votes
0answers
130 views

What tests can be performed to test the purity and quality of the raw peptide HCG (Human Chorionic Gonadotropin)

What tests could be run to test the purity and type of HCG? We are looking to purchase HCG from China but the purity and quality varies between labs, we are able to receive samples of the raw peptide ...
1
vote
1answer
103 views

How are the correct tRNAs transported to the ribosome?

I have been trying to understand how the tRNA transporting the correct amino acid required by the ribosome reaches the ribosome. The only way I can imagine this happening is that all types of ...
2
votes
1answer
113 views

How does GTP help in the step of codon recognition?

The anticodon of an incoming tRNA base pairs with the complementary mRNA codon in the A site.Hydrolysis of GTP increases the efficiency and accuracy of this step. How does GTP do so ?
8
votes
2answers
1k views

why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
1
vote
1answer
128 views

Does animal fat and meat contributes differently to our body?

Is animal fat harmful to our body or is it harmful if the amount eaten exceeds a certain amount? I have heard fat is more concentrated than protein. If I am correct then we can get more energy from ...
2
votes
2answers
3k views

Why restriction enzymes cut (usually) at palindromic sequences?

Restriction enzymes usually cut only at palindromic sequences. Is there any specific reason for that ? Is there any advantage for bacteria if it cuts up virus at this type of sequences ?
3
votes
1answer
120 views

Are similar smells usually based on similar chemicals?

Building off of this question: Why does freshly cut grass smell like a watermelon?, is it usually the case that things that we perceive as having similar smells are, in fact, the same or a similar ...
3
votes
1answer
924 views

What is DNA binding domain? It is not clear what the domain means

I am confused about the term DNA binding domain. Does it mean that there are some parts of the DNA that tends to coil up? Does it happen because some proteins tend to stick around that area? Also it ...
3
votes
0answers
39 views

Statistics on energy consumption breakdown per biological functions across organisms?

Are there any statistics available on how much energy organisms use for each biological functions (i.e. something similar to the line of "Bacteria spend X% of energy on information processing, Y% for ...
8
votes
1answer
93 views

Why pouring salt in the wounds is painful?

Pouring salt in the wounds is so painful. I am sure you all experienced this. whats happend there?
2
votes
1answer
92 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 ...
1
vote
1answer
107 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?
4
votes
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 ...
1
vote
1answer
168 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
votes
1answer
296 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 ...
2
votes
1answer
458 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 ...
3
votes
3answers
123 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.
18
votes
3answers
925 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 ...
0
votes
1answer
141 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 ...
4
votes
1answer
161 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
votes
2answers
272 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 ...
1
vote
1answer
53 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 ...
1
vote
2answers
121 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 ?
0
votes
2answers
119 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?
2
votes
0answers
151 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 ...
1
vote
0answers
38 views

Protocol for immobilize oligo to solid

I'm learning about microarrays and understand that an oligonucleotide can be immobilized to a solid like a CD acrylic plastic by modifying the oligo. Does anyone have a good protocol for modifying a ...
0
votes
1answer
58 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 ...
0
votes
1answer
52 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 ...
5
votes
2answers
197 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?
2
votes
2answers
212 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 ...
5
votes
3answers
128 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 ...
1
vote
2answers
307 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 ...
4
votes
2answers
375 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 ...
0
votes
1answer
136 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
1
vote
0answers
46 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
votes
1answer
47 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 ...
2
votes
1answer
788 views

Why is allolactose the LacI inducer?

For what reason(s) is allolactose, instead of lactose, the "natural" inducer of lac operon repressor?
0
votes
2answers
73 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 ...
3
votes
1answer
495 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 ...
2
votes
1answer
101 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 ...
5
votes
1answer
86 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 ...
2
votes
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? ...
1
vote
1answer
63 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?
1
vote
1answer
60 views

Do Acyl Carrier Proteins and Conenzyme A have similar reactivity?

In terms of the reactions they undergo are they roughly equivalent groups?
2
votes
1answer
40 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
votes
1answer
69 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
votes
1answer
116 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 ...