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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Is Roundup toxic?

Roundup, as we all know, is a herbicide that kills weeds. It does this by preventing the production of amino acids in plants. One of these amino acids is tyrosine. Tyrosine is a nonessential amino ...
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1answer
746 views

Why does NAD+ become reduced if it gains a hydrogen proton?

I've heard that $NAD^+$ gains a Hydrogen proton during glycolysis and the Krebs cycle and becomes reduced to $NADH$. However, isn't reduction when a molecule receives an electron? Maybe I've been ...
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1answer
193 views

What are 'acid stable' amino acids?

I tend to see terms amino acid, acid stable amino acid, and free amino acids used often in ...
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45 views

Which Lactobacillales (Lactic acid bacteria — LAB) strains are capable of degrading starch?

I've been researching bacteria strains but am having trouble finding amylolytic LAB strains with amylolytic and lactic acid producing character. The only species I've found, that are capable of ...
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1answer
30 views

kinetics question [closed]

An enzyme has a $V_{max}$ of 50 $\mu$mol product formed $(min * \text{mg protein})^{-1}$ and a $K_m$ of 10 $\mu$M for the substrate. When a reaction mixture contains the enzyme and a 5$\mu$M ...
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1answer
123 views

Bradford Reagent Disposal

I am a graduate student volunteering in a professor's lab being tasked with finding out how to dispose of certain hazardous materials. I have encountered a problem with disposing of Bradford's ...
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2answers
70 views

metabolism preference by the body

What I know about metabolism is that,during exercise body uses carbohydrate first then fats and then protein,so my question is why does body prefer glucose first as fuel for energy and what makes ...
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2answers
368 views

Is it possible to stop yourself from going into shock?

https://en.wikipedia.org/wiki/Shock_(circulatory) I was helping someone move a refrigerator down steps and it slipped while I was holding a sharp corner and it sliced my finger and there was ...
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1answer
51 views

Where does the inverse seconds unit come from in the association constant?

I'm working to determine Kd(s) kinetically by generating association and disassociation curves. Kon (association constant, or on-rate) is in inverse seconds multiplied by inverse molar. I get that ...
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39 views

What cures pineapple burns?

If you already ate too much bromelain in pineapple, how do you cure your tongue burn?
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32 views

Is there a good easy protocol for extracting proteins(enzymes) from fungal mycelium?

I quantify the enzyme (polygalacturanase)activity by DNSA method.To determine endo-polygalacturonase activity I'm searching for a good easy enzyme extracting method.Any suggestions for a suitable ...
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1answer
69 views

which organelle produce glycogen phosphorylase and why

I know that Glycogen phosphorylase doesn't produce from rough endoplasmic reticulum in liver cell. But almost every proteins such as insulin receptor, serum albumin, and lysosomal enzyme have to ...
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16 views

Growth of Yeast in Different pH Mediums

Will yeast grow better in acidic, basic or neutral mediums? Why? Will the medium affect the growth of yeast? (Yeast cell membrane is semi-permeable).
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67 views

What are the differences between carnitine forms?

I've heard of L-carnitine, acetyl L-carnitine and L-carnitine L-tartrate. What form(s) occur in meat? What form does the human body manufacture? Is L-carnitine just a shortened name for L-carnitine ...
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1answer
99 views

What do the numbers in Photosystem I P700 and Photosystem II P680 stand for? Is it the optimum wavelenght? The maximum wavelenght?

I am a bit confused about this because my teacher and english Wikipedia say it's the wavelenght the Photosystem is most reactive to; my textbook and the german Wikipedia say that it is the maximum ...
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33 views

Question about Collagen and Glycosylation

Just curious, I know that collagen typically undergoes O type glycosylation. However, can you say that this type of glycosylation is essentially like putting a mailing address for proteins to be ...
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1answer
174 views

Why does SDS-PAGE use for protein, and agarose use for nucleic acid?

My question maybe very primary, but after I learned this part, questions always follow me. SDS-PAGE gel works for detect protein, agarose gel works for detect nucleic acid, so here is my question: 1. ...
3
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1answer
159 views

Membrane Permeability to Pyruvate

Pyruvate seems to pass easily through the outer membrane of the mitochondrion but has difficulty entering the inner membrane (and gets in by H+ symport). I have two questions: (1) what property of ...
2
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1answer
403 views

How to find the concentration of an enzyme?

I need to know the concentration of pectinase enzyme (sigma aldrich) which has stated 5KU, 5U/mg protein (lowry) and lot result 20U/mg protein in the label of the enzyme bottle. This is all it has ...
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1answer
43 views

Making positive charged polyacrylamide

I am interested in positive charged polyacrylamide to electrophorese molecules I am interested in. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2643323/ ...
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0answers
38 views

Birth control hormones in the water? Or not?

This prior question talks about natural estrogen (TL;DR: Months to years): How quickly do estrogens break down in the environment? Ref: http://dx.doi.org/10.1038/485441a A lot of media has said, ...
2
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3answers
797 views

Do we consume dna, proteins of other organisms?

When we eat raw meat, e.g. chicken or fish, we are actually consuming the DNA, proteins etc. which are present in their cells. Wouldn't this affect our cell functions as this DNA might enter our ...
5
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1answer
249 views

Why is it often the case that an enzyme is favorable only towards one direction of a reaction and not both directions?

In class when we're studying enzymes like amylase or protease it only works well when you're using it to break down compounds like polysaccharides. I'm just curious but why is it not possible for ...
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1answer
84 views

What is a detailed chemical explanation for describing how an enzyme may lower the activation energy of a reaction?

If you can provide some sound reasoning that touches on tertiary structures of proteins and does not use a lot of advanced chemistry jargon that might be really helpful, especially for an intro ...
2
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1answer
69 views

Fibronectin glass surface adsorption

Short summary I'm having a glass surfaces and I want to adsorb proteins onto them. I have no problem, when I first adsorb fibronectin (human) onto some areas and afterwards any other protein. The ...
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1answer
132 views

What is a mechanical cue?

I was attending a talk related to neurogenesis. So one professor was asking a question related to biochemical cues and mechanical cues (related to signaling pathways I believe). Cue as far as I ...
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32 views

Soy kefir that never revitalises in animal milk

If I have kefir grains from goat and I make soy kefir and never revitalise the kefir grains in an animal milk, will that bacteria still be beneficial for the gut? What type of bacteria does it make? ...
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1answer
138 views

How will changing the concentration of a Tris buffer affect amylase enzyme activity?

For instance if you increase the amount of Tris but pH still does not change then will the enzyme activity still proceed normally? If it does change the pH will it change enzyme structure and why?
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2answers
124 views

How do muscle cells synthesize glycogen?

Hexokinase enzyme is present in all cells (including muscle cells) and can be suppressed by excessive G-6-P product. So that's why in the liver, glucokinase can act on glucose without inhibition of it ...
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0answers
77 views

Root etiology of non-pituitary low T4 and low TSH

Please note: I'd like to preface this question by stating that this is neither homework nor me seeking medical advice. I am simply trying to understand the biological, physiological root etiology ...
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0answers
30 views

Consumption of different type of energy when one is inactive

I'm wonder if there is any study done on this and what are the results? how much of each type of energy one's body(healthy normal person) uses when inactive(seating down) I know there are alot of ...
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1answer
142 views

Why do the deoxyribonucleotides use T and ribonucleotides use U? [duplicate]

We all know deoxyribonucleotides form DNA while ribonucleotides form RNA, DNA is double stranded while RNA is single stranded, and RNA can transcribe from DNA. We also know that DNA use A, G, C, T, ...
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2answers
46 views

Properties that can be derived from amino acid sequences [closed]

What are the properties that can be derived from an amino acid sequence apart from those mentioned in the website? In the mentioned website, the properties that can be calculated from amino acid ...
3
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2answers
284 views

Equilibrium and Metabolism: Can cells exist at STATIC equilibrium? What about dynamic equilibrium?

I understand that in closed systems, once reactions reach equilibrium, they can no longer be used to power other reactions. If a cell was a closed system (which it is not), being at equilibrium would ...
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1answer
114 views

Are all dipeptides synthesizable?

Probably a basic question, but are all possible dipeptides synthesizable? For 20 amino acids, there should be in principle 190 dipeptides; do they all exist or is there chemistry that makes some ...
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1answer
44 views

Is galvinoxyl antioxidant assay possible using NMR spectroscopy?

I would like to perform an antioxidant assay using the galvinoxyl protocol. The protocol states that we need EPR spectroscopy, but only NMR spectroscopy is available at my institution. Is there an ...
2
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2answers
122 views

Extending a small fragment of DNA

Is there a way to extend a small fragment of DNA, say 150 bp, by making copies of itself and attaching each copy of that small fragment to the end of that 150 bp sequence? For example, I want a 1 ...
3
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3answers
222 views

Why does all life use the same macromolecules in their genetic code?

There is no biochemical constraint of any sort, so why doesn't some other code work? Why is it specifically RNA/DNA?
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1answer
90 views

What happens when we eat excess fat?

The fats in our body are stored in fat cells. When we over eat fats does the size of our fat cells increase, are more fat cells generated, or do we "throw out" excess fat?
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2answers
81 views

How to read this diagram?

I have diagram of oxidative decarboxylation of pyruvate pathway. The pathway is between glycolisis and Krebs cycle. How to read this diagram? This excerpt from Harper's Illustrated Biochemistry, ...
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1answer
454 views

Does the cell internal temperature changes in response to a change in external temperature?

Background Some species are homeotherm (internal temperature is not affected by a change in external temperature) and some are poikilotherm (internal temperature changes in response to external ...
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2answers
208 views

Energy released during the production of ATP?

When glucose is used during aerobic and anaerobic exercise, how much energy is expended or required? During aerobic exercise: $C_6H_{12}O_6 + 6 O_2 \to ATP + H_2O + 6 CO_2$ + energy During ...
2
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1answer
489 views

Does pH affect Michaelis constant?

I have been trying to confirm the Km of a substrate (which is 34 +/- 4 mM). This value was obtained in 50 mM MOPS, pH 6.3. I conducted my kinetics assay in a buffer of pH 7 and obtained a Km value in ...
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0answers
13 views

Biomolecule , DNA-RNA difference [duplicate]

Why is that a RNA has uracil in place of thymine? RNA could have thymine bases but it has uracil ? What is the reason for the presence of uracil there ?
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0answers
95 views

How can we determine the polarity of fat molecules?

I'm trying to solve a question in a biochemistry quiz, which is asking for classifying a set of lipidic derivatives, by increasing polarity. Unfortunately, we didn't cover the classification of ...
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1answer
31 views

How is Glycophorin A and straphylococcal related to Escherichia coli and what does readily purified mean in this context?

I am reviewing the paper "Glycophorin A Dimerization Is Driven by Specific Interactions between Transmembrane Alpha-Helices." There is a statement in the abstract which I don't understand: "The ...
3
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1answer
83 views

Ways to fight black mold

Is it possible to introduce a microorganism to a colony of black mold that will kill off the black mold entirely and permanently? Is there a common microorganism that likes to eat them and is harmless ...
5
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1answer
87 views

How do single-celled predators chase other cells?

From my understanding, single celled organisms have been seen avoiding, and chasing, potential food or other organisms. How do they accomplish this? They do not have eyes or ears or a nervous system. ...
3
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0answers
58 views

What Chemical Trigger Causes Ectomycorrhiza To Change From Asexual To Sexual?

I want to know the trigger behind the change of asexual to sexual ectomycorrhiza when symbiosis with a tree root is formed. As ectomycorrhiza attaches itself to a root, it forms a relationship wherein ...
2
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1answer
36 views

Finding a reaction from a KEGG map

I have come across a map and a part of it looks like this: Now I have not been able to locate the reaction that converts alpha D-Glucose to Glucono-1,5-lactone but was successfully able to locate ...