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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Write a short note on chemiosmotic theory [on hold]

I request the answerer to write a note based on the points discussed below (for Minor level). I couldn't find any website or book stating the chemiosmotic theory. So I request the answerer to provide ...
3
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1answer
58 views

Forgot to vortex antibody before staining

Ugh. Did an immunofluorescence experiment last weekend, forgot to vortex both my primary and my secondary antibody solutions. And my final result looks dimmer than it should be. Is it possible that ...
4
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1answer
41 views

Why is the Pentose Phosphate Pathway so active in erythrocytes?

Is it because glyceraldehyde -3-phosphate (a molecule which when enter glycolysis help produce ATP through substrate level phosphorylation) can be prepared without losing an ATP through this process?
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1answer
24 views

Why does uncompetitive inhibition decrease the Michaelis constant?

I can't seem to find a good resource online that clearly outlines the difference between an uncompetitive, noncompetitive, and mixed inhibitor (I understand competitive inhibitor though). More ...
4
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1answer
85 views

Can the human body create glucose out of fat?

I read conflicting views about whether or not the human body can create glucose out of fat. Can it?
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18 views

Why is the formation of an enzyme-substrate complex endergonic (induced fit model)?

In the section about the induced fit model for enzyme substrate binding, my MCAT textbook claims that "The substrate has induced a change in the shape of the enzyme. This interaction requires energy, ...
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24 views

To which functional group DNA and RNA shows higher affinity of binding [closed]

i want to know if a DNA or RNa binds to any nano particle via functional group playing role which functional groups must have to bind DNA and RNA
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1answer
31 views

How does 2-mercaptoethanol lead to shift of the band to a higher molecular weight?

I have a project to isolate a protein with biological properties from a plant. The purified protein forms four bands with similar molecular weight on SDS-PAGE (30–35 kDa) in the presence of 5 % 2-...
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2answers
42 views

Do disaccharidases require a cofactor or coenzyme to function?

I'm doing research on lactose intolerance and am curious if disaccharidases (enzymes that break down disaccharides) require a cofactor or coenzyme to function? Reviews or references would be greatly ...
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1answer
54 views

Beta Sheets vs Alpha Helix - Strength

Is there a hard and fast rule of which one is stronger than the other, or does it depend on their context in a protein?
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28 views

Where does transamination and deamination take place?

The only information I know is about deamination,it occurs in the liver and kidney. But in which part of the cell does deamination occur? To which tissues is transsamination specific to and in which ...
3
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1answer
36 views

Why does migration distance depend on log of molecular weight in SDS-PAGE?

I really want to know why in the result of SDS PAGE, log of molecular weight(MW) and migration distance (distance from the loading well) have a linear relationship. Why is it log(MW) instead of MW? ...
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1answer
18 views

Binding kinetics of 6xHis-Tag

For the planning of an experiment I would like to know the binding kinetics (kon and koff) of a 6x-His-tag to a Ni-NTA surface. I know they should differ due to surface quality and position of the ...
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23 views

Can the respiratory quotient be calculated from a formula or must it be measured directly?

I found the following question on the Respiratory quotient: A normal human diet has a Respiratory quotient (RQ) of approximately 0.85. Given that pure oxidation of fatty acids has a Respiratory ...
4
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1answer
55 views

Does the formation of water inside the mitochondrial matrix help contribute to the proton gradient during the electron transport chain?

Does the synthesis of water in the final step of the electron transport chain significantly increase the electrochemical gradient across the matrix? I understand that pumping protons out of the matrix ...
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0answers
8 views

What steps need to be taken between a successfull SDSPage GE and MS/MS?

Once you have your gel with separated proteins can you simple cut out each band and plop it into solution or do you need to take extra steps?
14
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1answer
151 views

What's the mechanism for being mentally tired?

I notice that after long tests, or long periods of critical thinking, my body and mind feel noticeably tired. Why does this happen? Are the neurons in my head not firing as quickly, or is there just a ...
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1answer
50 views

What is an interaction motif with respect to protein sumoylation?

While am reading about protein sumoylation this morning I got stuck on sumo interaction motifs and consensus motif line. I heard the the word motifs for the first time. What does motifs mean in this ...
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1answer
50 views

Use of western blotting

I ran across this paper recently. http://www.ncbi.nlm.nih.gov/pubmed/21151122 I am confused on their use of Western blotting. Their unmodified protein (no PTM group) has a band and their modified ...
2
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1answer
63 views

Electron balance for biomass synthesis: is my professor right?

I'm studying for my exam and I came across these notes written by the professor himself. He's talking about the general reaction of biomass production in a bioreactor: $$\ce{C6H12O6 + NH4+ + O2 -> ...
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2answers
47 views

Why is oxygen and CO2 measured in pressure instead of mmoles/L like other ions?

Na, K, Cl...All measured in mmol/L in plasma. Why is oxygen and CO2 measured in pressure (mmHg)? (I guess it has something to do with them being bound to RBC but I don't know why the difference).
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4 views

In a condensation reaction, which of the reactants loses their OH group? [migrated]

You have Propanoic Acid ( CH3CH2COO-O-H) so an OH on the end You have Ethanol (CH3CH2-OH) so an OH on the end When you combine the two for a condensation reaction you have the OH group from 1 ...
7
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1answer
375 views

Why should phospholipid non-polar tails be “protected” in the membrane bilayer?

lipids are arranged within the membrane with polar head towards the outer side and non polar tails towards inner side, this ensures that the non polar tail is protected from aqueous environment. My ...
3
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1answer
19 views

How would one determine whether a chemical will upregulate a certain class of proteins?

I'm trying to determine whether certain organic chemicals will upregulate classes of proteins that possess deacylase activity.  How would I go about this experiment? I'm assuming I would use some ...
2
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1answer
104 views

How to retrieve logical expression (KO based) for reactions from KEGG?

Whether a module is complete or not can easily be checked by evaluating the Definition entry associated with the module; e.g. in module M00010, it is given by <...
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1answer
44 views

Lifetime of secondary messengers such as Calcium or IP3

Can anyone suggest me literature on the lifetime of secondary messengers such as calcium or IP3? A book would be preferred. What I am specifically looking for is a validation that secondary messengers ...
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22 views

Plasmid electrophoresis with DNases

DNases are used for treatment of cystic fibrosis. A normal DNase catalyzes the hydrolytic cleavage of phosphodiester bond in one strand of DNA. Scientists, in order to improve efficacy of DNases, use ...
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26 views

How do organoarsenics improve digestion efficiency in poultry?

It struck me as very surprising that these organoarsenic compound with structure looking not very compatible with living system is widely used as food additive to increase weight gain and improve food ...
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1answer
14 views

When is Pheophytin used in electron transfer to the q cycle in plants?

If I understand it correctly: (short version) The Q cycle starts with PQH2 it removes the 2H(+) and gives one electron to Plastocyanin and the other to a stored Plastoquinone to charge it to ...
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0answers
24 views

Insulin and leptin action on Anorexigenic Neurons in Hypothalamus?

Receptors for Insulin are present on liver, adipose tissue and muscles BUT also Insulin Receptors are present in arcuate nucleus of hypothalamus where it influences anorexogenic neurons through IRS2 ...
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1answer
37 views

Why are both glucagon and cortisol released in hypoglycemia?

Cortisol is released in response to prolonged stresses; one situation when cortisol is released is when blood glucose level is low. In this situation cortisol acts on adipose tissue promoting fatty ...
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10 views

Hyperglycemia in Type 1 Diabetes?

Glucose transporters GLUT1, GLUT2, are always present in hepatocytes membrane and GLUT3 on brain cells but the glucose transporters for skeletal muscles, cardiac cells and adipose tissue are not ...
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0answers
28 views

Fate of Acetyl CoA in well fed state?

When we have eaten well and take fat rich diet then in this condition Acetyl CoA produced from fatty acid breakdown will be gone to storage in adipose tissue or not? If it will go for storage then why ...
3
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22 views

Effect of ethanol and detergent on cell membranes problem

I am currently writing my biology report for an experiment I did on how ethanol and detergent affect the cell membrane. For my ethanol experiment, all went as expected BUT for my detergent experiment, ...
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1answer
63 views

Do two compatible tRNA codons bond together?

Can two tRNA with complementary anti-codons link together? For instance UUU with AAA. If not, why not?
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10 views

How were CDK1 and cyclin B identified?

I know that MPK is a dimer containing cyclin B and cdk1 and this promotes entry into mitosis. The experiment I have found was that when MPFs were micro-injected into frog oocytes arrested in G2, the ...
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28 views

Estimating RNA concentration from Specific Activity of Labeled RNA

The question reads, Using T7 RNA polymerase to transcribe in vitro a 100-nt RNA off a DNA template. This RNA contains 19 Adenosines. In your 100 uL transcription reaction you added 1.00 µL of α32P•[...
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13 views

How many ATP can be bound to f1 of ATP Synthase?

Diagrams show a bunch of ATP being produced simultaneously, is this possible? Or is it one ATP per rotation of ATP Synthase?
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23 views

Loooking for dataset of proteotypic and non-proteotypic peptide

I'm experimenting with peptide prediction using machine learning. I need some data for testing. I already have one dataset, but I need another one or two for verification. I'm looking for data for a ...
0
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1answer
33 views

Amino acids in human cancer cells expose dextrorotation?

I would like to know if the amino acids in the human cancer cells are dextrorotatory or levorotatory. I mean the majority of them. They expose levorotation just like the amino acids in the normal ...
7
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1answer
276 views

Why is aconitase classified as a lyase?

Aconitase in the TCA (tricarboxylic acid) cycle isomerizes citric acid to isocitric acid via cis-aconitic acid intermediate. Since overall it functions as an isomerase, why it does not belong to ...
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1answer
29 views

Does CoA always bind to organic molecules through a thiol bond?

Does CoA always bind to organic molecules through a thiol bond? Sometimes I see it written as SCoA in textbooks but sometimes it's just written as CoA, are those actually chemically different, or just ...
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1answer
65 views

Do different emotions produce different tears?

Do tears of joy, laugh, grieve, and others contain different things or are they all the same?
2
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1answer
37 views

How many rounds of TCA Cycle would a complete oxidation of a triacyl(15-Carbon fatty acid)-glycerol, give?

This was a trickier question on a previous test, and I'm still not sure why, but the answer was "at least four". I answered "more than 22" and got it marked wrong. I assume that each fatty acid chain ...
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1answer
37 views

Can you replace glucose with glycerol in cell media?

In order to feed an animal cell in process called Respiration, can I replace Glucose with Glycerol? The Equation bellow: Glycerol + Oxygen -> Water + Carbon Oxide
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1answer
32 views

Is there a difference between “Alpha Helix” and “Alpha subunit”?

In my biochemistry textbook the terms alpha helix and alpha subunit are both used. Are these two terms synonymous? For instance, hemoglobin has an alpha and beta subunit, are these the same thing as ...
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22 views

peritoneal dialysis Vs Hemodialysis?

Their are basically two types of dialysis: 1.peritoneal dialysis 2.hemodialysis, My Question is Why the peritoneal dialysis needs to be carried out on everyday BUT hemodialysis is carried out on only ...
0
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1answer
45 views

Diabetes Mellitus and renal failure?

I have studied that Diabetes Mellitus leads to kidney failure and that this is because of the damage to the blood vessels (especially the blood vessels in the kidney) due to high levels of blood ...
1
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1answer
87 views

Is there nothing such as NADPH2? [duplicate]

I have gone through various sites and some say there is NADPH2 and some say there is no NADPH2 there's only NADP+ ...WHich is the correct view....Please dont mark this answer as duplicates since I ...
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1answer
55 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 ...