Questions tagged [biochemistry]

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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1answer
66 views

Enzymes extracted from diferent tissue, may have diferent $K_m$ values under the same conditions?

My laboratory team has been used succinate dehydrogenase (1.3.5.1) from Gallus gallus domesticus breast (the most meated part of the chicken, where you will obtain nuggets) to determine $K_{m}$ and $...
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1answer
80 views

Why do we need to amplify DNA sequences?

I am learning about biotechnology. I have no education in biology or chemistry and am simply interested in the subject of biotechnology. I am wondering why we need to have multiple copies of a piece ...
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1answer
39 views

Is glutamate always involved in the deamination and amination of the other amino acids?

For example, are there pathways for the deamination of phenylalanine that simply produce ammonia or pathways for it to be synthesized from phenylpyruvate with ammonia being utilized to form the amine ...
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85 views

Can undigested food proteins enter the bloodstream? [duplicate]

I know that food proteins in our digestive system are denaturated and broken down into amino acids or very small peptides that are then absorbed in the small intestine. If some proteins stay ...
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Why aren't diatoms' shells used as a temperature proxy, but foraminifera shells are?

Changes in oceanic oxygen isotope ratios (O-18 to O-16) are reflected in the shells of ancient foraminifera. But I never hear of diatom shells being used, even though they were/are at least as ...
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Coagulation of protiens of different products

Protein of egg coagulates on 60 degree but proteins of milk do not coagulate at high temperatures..why? What is the main reason behind all this?
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Theoretical basis for amphetamine salt combo(Adderall) vs Dextroamphetamine

After re-reading the help questions I think this belongs here as I am more interested in the biochemical motivations rather than any medical query or advice(but may also fit Chemistry SE). So from ...
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4answers
171 views

Cheap enzyme assay for a high school lab

At the moment, I'm designing an experiment for a high school lab with no financial resources. I need to assess the impact of a variety of factors on a specific enzyme's reaction with its respective ...
2
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1answer
46 views

Do there exist enzymes that can take up multiple cofactors to do different reactions?

I was thinking about enzyme catalysis, and it seems like enzymes can only catalyse one kind of forward/reverse reaction (please correct me if I am wrong). Does there exist an enzyme that can catalyse ...
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How much Oxygen can the Human body carry?

Basically - the title: How much Oxygen does a human body carry at a single point? What have I tried: A friend of mine has done some calculations and came up with the following numbers. Neither of us ...
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2answers
55 views

What is the water and fat composition of the human brain?

Everywhere I look online says the brain is about 60% fat. But when it comes to water, I see numbers like 70-75%. One webpage even makes both those claims back to back! That doesn't make any sense. So ...
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42 views

Ligand-binding assays: IC50, EC50 and Kd

I am reviewing several MHC-peptide binding affinity predictors trained on IEDB data. Quantitative records for MHC class I allotypes come from a lot of different assays and, by extension, have ...
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Which one is better to use for water stress experiment GWAS or RNASeq?

This is my first time in this area of research. I am working on 95 varieties of bambara groundnut. I have done the agromorphological characterization of these varieties as well as the genetic ...
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1answer
62 views

How does a ribosome gather tRNAs at a fast enough rate for Translation?

There are many animations of the ribosome in action, and all I have seen show the correct tRNA neatly entering the ribosome and its amino acid being added to the growing protein chain. My question is ...
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31 views

Could ions inside lungs produce hydroxyl?

I am not proficient in either biology or chemistry. However, I have a question which I can't find answer to. It seems to belong somewhere between chemistry and biology. I apologize for any errors and ...
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384 views

What are the marker enzymes for Nucleus, Ribosomes and cell membrane?

Are there any marker enzymes present for ribosomes, nucleus and cell membrane. For mitochondria there are many, for lysosome it's cathepsin. I read about the marker enzymes of most of the other ...
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2answers
69 views

Are tumor-associated antigens unique to cancerous cells?

Are tumor-associated antigens found only on the membrane of cancerous cells or just over-expressed on the membrane of carcinogenic cells? In other words, are these antigens also found on healthy ...
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1answer
18 views

Does Cholestyramine (CSM) raise Tyramine levels?

This is a layman's question. Will ingesting Cholestyramine (CSM, the resin, in powdered form to be specific) raise tyramine levels? I am asking because Cholestyramine clearly has "tyramine" in its ...
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0answers
66 views

Why is sorbitol used in buffers?

Many protocols in my lab use sorbitol in buffers. For instance, in co-immunoprecipitation, we include it at a final concentration of 200 mM in our lysis buffer. I'm not entirely sure why though. I ...
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2answers
119 views

About the definition of ketogenic amino acid

I am studying biochemistry and have been looking at metabolic network diagrams showing the different intermediates of glycolysis and the citric acid cycle that amino acids can be converted to. I have ...
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1answer
54 views

Why doesn't chloride cause high blood pressure?

Assuming osmotic pressure is the (main?) culprit, why isn't the chlorine ion loose in your body after eating salt considered equally responsible for hypertension? I have searched Google and Wikipedia,...
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38 views

What is the chemical structure of myosin? [closed]

What is the chemical structure of myosin? Specfically, what functional groups or monomers are they made of?
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1answer
1k views

What animal has fat with the highest energy density?

Fat is more energy-dense than protein and carbohydrates, it is not only an energy deposit but also an organ with many functions such as cushioning and metabolism regulations. I want to know are animal ...
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1answer
67 views

Why do we need to grow plants to make food?

Why can't we synthesize the nutrients that we need directly from chemical reactions, from energy and simple inorganic molecules found around us? If it's hard, why not try to copy how plants do it? I ...
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1answer
29 views

What is ApoCas9 in the CRISPR-Cas9 system?

I am currently reading an article about a particular assay of Cas9 nucleases. In one of the experiments, they have used ApoCas9 (Apo variants of other CRISPR nucleases) as some sort of control. But ...
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1answer
39 views

Which chemokines are being produced by melanocytes?

I am looking into Vitiligo it's an autoimmune disease that results in apoptosis of melanocytes due to misfolded protein accumulation. It also dramatically increases breast cancer rates (600 times) ...
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Why have plants evolved to photosynthesize glucose instead of another molecular compound?

I think this question can be broken down into two sub-questions: Why do plants produce $C_6H_{12}O_6$ as opposed to another molecule following the formula of $C_nH_{2n}O_n$? Why not $C_8H_{16}O_8$, $...
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Why isn't the human zygote considered a human life how is a living anatomically modern human defined biologically? [closed]

It has 46 chromosomes by default when healthy(Differences almost always are pathological) and has almost every biological functions, processes a Newborn or and Adult person has. It even invades ...
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1answer
126 views

Difference between fertilin and fertilizin

I am confused between fertilin and fertilizin.Are these two same or different? Here are a few sources i referred Julian Lombardi (auth.) - Comparative Vertebrate Reproduction-Springer US (1998) Page ...
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1answer
101 views

Cerebral/Cerebellar Cortex versus Deep Nuclei

I have troubles using the terms Cortex & Deep Nuclei, and 'Nuclei' in general. From what I understand, a brain has '3 matter types in accordance to anatomical locations' Superficial Grey matter - ...
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163 views

Meaning of units in ELISA based tests?

For some ELISA based antibody tests (e.g. h-tTg antibody test), labs report units as RU/mL or U/mL. Also different labs have different cut off (normal range) values. I understand that different kit ...
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25 views

How are humanized antibodies made?

What kind of antigen is used to provoke/induce an immune response if you are trying to make therapeutic humanized antibodies for cancer and alzheimer's disease? For example, if you wanted to make an ...
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50 views

What enzyme or bacteria could dissolve plastic?

What enzyme or bacteria could dissolve plastic aside from acetone? Preferably, low-cost and environmentally friendly. Any suggestions would be helpful. I'm targeting for thin plastic (low-density ...
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2answers
71 views

What is the subcellular location of synthesis of non-essential amino-acids?

What is location of non-essential amino acids synthesis in a cell? Is it some specific organelle? And what is the gene driver behind this? I thought the whole point of DNA is coding for how to ...
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1answer
34 views

How can I get the yield of my purified immunoglobulins?

In order to get the yield of IgY through a set of purification steps, what method can I use? Thanks in advice!
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27 views

Biochemistry of pleasure of/desire for physical exercise in mammalians and humans?

Are there some known biochemical mechanisms, that induces desire for/pleasure of physical exercise in mammalians and humans? I have heard, that horses can not live without physical exercise and they ...
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4answers
368 views

How can I change my buffer system for protein purification?

I have a protein that I purified in PBS buffer, pH 7. I will do dialysis to remove salt and will then further purify the protein with ion exchange chromatography. I will need to use another buffer (...
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1answer
47 views

Rice left in water for several months - what biological reactions or growths would occur?

In an attempt to make a hair care product, uncooked white basmati rice was left in an air-tight container half filled with tap water for several months. When opening the container, the smell was ...
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30 views

How to troubleshoot in vitro formaldehyde fixation for nucleosomes?

For an experiment, I am trying to fix the mononucleosomes (100ng) using formaldehyde as crosslinking agent in HEPES buffer. I have been using 2% formaldehyde in a reaction buffer containing 1mM EDTA, ...
3
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1answer
174 views

Cellular respiration in carnivorous animals

What is the equation for cellular respiration in carnivores as they don’t consume carbohydrates to break down into glucose in the following manner: Glucose + oxygen -> water + CO2 +energy. Do they (...
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0answers
52 views

Why is double stranded DNA considered to be one molecule? [duplicate]

Wikipedia, for example, refers to DNA as "a" molecule, not two separate molecules forming a double-helix structure. Isn't this technically incorrect? There are two separate polynucleotide strands (...
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2answers
190 views

Edible and non-edible leaves [closed]

For humans, what's the difference between an edible leaf like lettuce, and a non-edible (in the sense of null nutritional value) leaf like grass?
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1answer
120 views

Blood acidity and bones

By consuming acidic foods, could one cause their blood to become acidic and therefore cause an acid+base reaction between their blood and bone? I ask this because i recently discovered bone is a ...
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38 views

Cooperative Enzyme Question

I'm currently studying for the MCATs. After doing some biochemistry practice questions, I came upon a question that I believe may be incorrectly posed. I was wondering if I'm correct in saying this or ...
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1answer
104 views

Difference between cerebroside and globoside

I have a general idea about their difference that cerebrosides have a single sugar while globosides have more than one sugars. This is the structure of a ceramide (syphingosine and a fatty acid ...
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Can a lentivirus expressed protein that is undetectable by western blot be detected by BioID?

Cloned a single herpesviral gene into pCDH-EF!-GFP and see phenotypic effect on cells of interest and viral gene transcripts BUT unable to detect ANY protein using HRP boosted western blot. Even with ...
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1answer
58 views

Why is beta- D fructofuranose two different structures when in free form and as part of sucrose?

This is the structure of fructose in free form: The right moiety is the fructose as part of sucrose. The left one being glucose: Both of the fructose are beta-D fructofuranose. But as it can be ...
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78 views

Does cat urine really fluoresce? If so, why?

I temporarily got caught in the Sad and Useless website, and found Science is Fun. Most of the claims seem plausible, but I can't guess why cat urine would fluoresce. Comments have directed me to ...
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68 views

Can something cause both breaks and cross-links in DNA?

A double strand break in DNA is exactly that: the strands of DNA are severed. A cross-linkage occurs when something forms a covalent bond between two nucleotides in DNA. However, is it possible for ...
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SDS-PAGE compared to western blotting

SDS-PAGE and western blotting are both used to separate and isolate proteins. My question is, which technique should be used when? Does one of them has advantages over the other one?