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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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Is it possible to stop more/extra fat from being stored in the body?

I don't mean simply by restricting eating or upping the activities, but a way to basically stop the body from adding more fat on itself down on the bio level. For example, I'm not too knowledgeable on ...
3
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0answers
15 views

What phosphorylates tau protein & and what causes tau to be phosphorylated?

I want to know what phosphorylates tau protein and its 6 isoforms. I know kinases cause phosphorylation events, and in tau it can be phosphorylated in a healthy neuron in the trans conformation, but ...
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23 views

Why does my face feel numb after eating an apple? [on hold]

Whenever I eat an apple (I don't know if only certain sorts cause this, unfortunately), my upper cheeks first feel flushed and warm, as though there is more blood flowing towards that part. Then, ...
4
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1answer
49 views

Backbone hydrogen bonds between adjacent amino acids in a protein?

Is it possible for two adjacent amino acids in a peptide to form hydrogen bonds between the backbone NH and CO? Are there any examples of such situations in proteins and how common are they? If ...
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1answer
142 views

Is the chemical composition of urine detrimental or beneficial for a tree?

Seeing as a lot of people around the world urinate against trees it came to mind that I never thought about how the tree responds to this. Is it detrimental for a tree if people urinate against them? ...
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0answers
19 views

which enzyme phosphorylates sodium potassium pump?

I know that Na+/k+ pump possess atp-ase function; so the pump will hydrolyze ATP into ADP + Pi. And I see in a figure that the pump is phosphorylated but couldn't really find which protein catalyzes ...
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22 views

Intein Splicing

Currently I am trying to read and understand this paper on intein splicing. https://sci-hub.tw/https://www.ncbi.nlm.nih.gov/pubmed/22001202 However, I'm a little confused with Figure 4. Why do the ...
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1answer
36 views

Does digestion require hydrochloric acid?

Would our digestion function any differently if we secreted something else, like sulfuric or nitric acid, instead? I'd assume an acidic environment may be required, but not sure if chloride is also ...
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1answer
38 views

If overcooked hard boiled eggs show these green sulfide rings, why do scrambled/fried eggs not show this?

In the image above, the dark green rings are ferrous sulfide rings, caused when the sulfur from the egg white reacts with the iron in the egg yolk when the egg is overcooked. I was wondering, given ...
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1answer
43 views

is a-keratin a fully functional protein?

is a-keratin before it coils with another polypeptide, makes chains, and build intermediate fillaments a fully functioal protein? I mean, is the single monomer of a-keratin a protein or it has to ...
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0answers
32 views

Do cats produce DMT?

There is a question on Skeptics.SE that asks if "cats have a chemical in their brains that resembles LSD." I haven't found any similar claim online, but started wondering: Do cats produce (natural) ...
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1answer
639 views

White residue from ginger juice

I’ve been juicing some ginger by grating it and pressing it (by hand). A white residue collects at the bottom of the liquid. What is this?
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1answer
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What are the (evolutionary) advantages of secondary transport?

Secondary active transport uses electrochemical gradients as a source of energy for the uphill transport of substrates (coupled to downhill transport of the ion). However except for in a few cases (e....
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1answer
18 views

Exocytosis of synaptic vesicles

I'm reading the following paper: http://jcs.biologists.org/content/123/6/819 The part I am really confused about is when they say: Exocytosis appears to use two alternative pathways: clathrin-...
2
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1answer
42 views

Does every protein starts with Methionine amino acid [duplicate]

During process of protein synthesis we need AUG Codon to start translation .As we know this codon codes for Methionine amino acid so can we say that every protein starts with Methionine amino acid ?
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0answers
25 views

What is the difference between Warburg effect and Crabtree effect in metabolism? [closed]

In addition to answering my question, please suggest a good review article that provides comparison of the above effects. Which pathways affect central carbon metabolism to produce these effects? Also,...
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1answer
27 views

Spatially Encoded GPCRs?

I'm reading this paper, and I'm already lost in terms of what they mean by GPCR signaling is spatially encoded. How can signaling be spatially encoded?
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1answer
14 views

Lysosomal Storage Disease

In my biochemistry class today we did a problem detailing two lysosomal storage diseases. In the first scenario, a cell line for I-cell disease can synthesize lysosomal hydrolases that are perfectly ...
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2answers
29 views

Base pair and amino acid weights? [closed]

How does a base pair weigh approx. 650 Da (which is two paired nucleotides) but an amino acid (3 nucleotides) weighs only approx. 110 Da ?
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0answers
8 views

Rhodamine 123 Staining Function

How does Rhodamine 123 act as a probe for Mitochondrial Staining? What is the Exact Biochemical Basis? and can it Stain Chloroplast as well? Thanks in Advance
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0answers
21 views

Can sperm cells penetrate the cell membrane of non-ovum cells?

Sperm cells have tiny bags of enzymes on their tip (the acrosome) which allow them to penetrate the ovum. My question is whether or not the process that allows sperm cells to penetrate the cell ...
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0answers
36 views

The truth behind human urine and marking territory?

So some years ago, I remember watching a survival show in which the host said that human males produce a type of chemical in the urine that animals such as wolves can acknowledge as a territory marker....
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0answers
54 views

The effect of salt, pH and temperature to the salivary amylase

If I prepare the following set of tests, incubate for 15 mins, then add 2-3 drops of iodine solution to each test tube: Salt test (1ml starch solution + 0.5 ml enzyme + 1ml 1M NaCl, incubate at 37 oC ...
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0answers
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Can the heart and other muscles function without creatine/phosphocreatine?

Skeletal muscles in the body have a small reserve of ATP. During the first few seconds after contraction, phosphocreatine is used by the enzyme creatine kinase in order to phosphorylate ADP to ATP ...
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0answers
37 views

How is it possible for phosphate to form two ester bonds in DNA replication?

I understand that in phosphodiester bond formation, two hydroxl groups on the phosphate molecule bind to the 3' and 5' OH groups on two independent pentose sugars. This is a condensation reaction, so ...
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0answers
54 views

Does our brain use up more ATP after smoking cannabis?

kind of an amateur here. If the firing of the neurons' signals uses up some ATP, and smoking cannabis makes them fire off more quickly, do our brains use up more ATP to sustain that rapid firing?
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2answers
423 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 L-...
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0answers
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Is there a relationship between HDL-C and LDL-C?

For a gentle introduction to cholesterol and its functions, see a great answer on SE Biology Whenever I read about how to deal with cholesterol level, the rule is to keep a low LDL fraction, ad a ...
2
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1answer
140 views

Is there any way to differentiate between a contractile and a non contractile vacuole by observation alone in any given organism

I have read about distinguishing them using osmotic experiments in books and here as well. But is there any thing common (on a biochemistry level) from which I can tell if a vacuole is contractile or ...
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3answers
745 views

Are there any multicellular forms of life which exist without consuming other forms of life in some manner?

The title is the question. If additional specificity is needed I will add clarification here. Are there any multicellular forms of life which exist without requiring the consumption (destruction) of ...
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1answer
498 views

What is the purpose of DMT in plants?

N,N-Dimethyltryptamine (DMT) is found, besides humans and other animals, in many plants(50+). In humans (in the pineal gland) it is suggested that it is used for our immune system. ...
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0answers
11 views

Isoelectric point of casein and soy

Why is the isoelectric point of casein protein similar to the isoelectric point of soy protein?
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1answer
105 views

What are the sources of molecular hydrogen in human breath?

In the BBC News article CES 2019: Tech preview of the expo's hottest new gadgets there is a new product that one can use to measure the hydrogen in ones breath, and this is supposed to have some ...
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0answers
39 views

Where do the protons in the mitochondrial intermembrane space originally come from?

I'm currently reviewing this concept in cellular respiration. The book which I'm using is Reece, Minorsky, Campbell's Biology and while it does a good job at explaining the process involved in the ...
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1answer
40 views

Depolarisation of post synaptic neuron

When the post synaptic neuron begins to depolarise as positive sodium ions move into it and it reaches threshold- does the inside of the neuron actually switch to being more positive than the outside? ...
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1answer
81 views

Why can't diamine oxidase be supplemented?

I've read from an academic article that diamine oxidase cannot be supplemented but it had no explanation as for why. I am curious as to why this? Food rich in histamine or red wine may cause ...
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0answers
19 views

How to recreate bioluminescence in a lab?

I have several mg/mL of D-luciferin, luciferase (firefly), ATP solution (25 mmol) and MgSO4 (for the mg2+ ions). The experiment has to be done in cuvettes of 2,5 mL (if I get any results, it will be ...
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1answer
116 views

What is the difference between a signal peptide and a transit peptide?

From what I know, the two names are used interchangeably and I haven't found any resource which says otherwise either. Is there at all any difference, is there a transit peptide that is not a signal ...
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1answer
1k views

Why are fatty acids consisting of even number of carbons predominant?

Most of the fatty acids in animal biology consist of even number of carbons in its parent chain. What property of such fatty acids cause the biological systems to prefer them over the odd counterparts?...
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27 views

Does eating food with MSG make you thirsty?

My grandma alleges that she's thirsty after a meal that doesn't taste salty, if and only if the food contains MSG (monosodium glutamate). Is she correct? She doesn't believe the answers in this ...
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0answers
16 views

Valence electrons in DNA nucleotide addition [closed]

Can anyone explain the movement of valence electrons during the nucleophilic attack that occurs during DNA synthesis? The 3' oxygen starts with two lone pairs of electrons but what happens during the ...
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2answers
684 views

Where does the proton come in the reduction of NAD?

In our curriculum biology textbook the reduction of NAD+ is depicted as follows: NAD+ + 2 H+ → NADH + H+ If this proton in the products was not present in the reactants, then where does it come ...
3
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1answer
70 views

How is bad garlic breath eliminated by swalllowing a bit of raw garlic?

Please bear with me, as I am just a poor physicist. I have learned how to make traditional pastourma from a recipe given by my late aunt Dora, which is like pastrami except with a very strong garlic ...
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2answers
112 views

How can dehydrogenation steps in some biochemical pathways produce ATP?

Dehydrogenation reaction of alkanes is inherently endothermic as one removes two thermodynamically more stable C-H bonds and replaces it with one less stable C=C. Although the product is conjugated ...
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2answers
2k views

What inactivates pepsin in infants?

In infants, rennin helps in digestion of milk. Pepsin is also present in their stomach. Why do infants need rennin for milk digestion, at the first place? Why does pepsin not act on the milk ...
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2answers
8k views

Why do some vegetables taste bitter?

Bitter gourd, cucumber, etc. are bitter to taste. Which chemical causes bitterness in them? I found these when I searched online: this says that it is because of calcium, while this and this talk ...
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1answer
101 views

Where would vegetarians/vegans get a substitute of hemo/myoglobin from?

As far as I understand, there is a difference in the iron absorbed from meat than from other sources like grains and vegetables. If this is the case, is it possible that not ingesting the hemoglobin ...
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3answers
18k views

Why do Type II Restriction Endonucleases cleave at palindromic sequences?

Type II Restriction enzymes usually cut only at palindromic sequences. Is there any specific reason for that? Is there any advantage for bacteria if they cleave phage DNA at this type of sequence?
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2answers
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Why isn't acetyl-coA an entry point for gluconeogenesis?

The process of gluconeogenesis starts from various possible precursors - plausible entry points like, Pyruvate, OAA, Fumarate, Propionate (as succinate) and alpha-KG. It is important to note that, ...
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1answer
34 views

Where do the lysines come from during ubiquitination?

I know that Ub forms an isopeptide bond with lysine, but where do the lysine come from? Are they just always available for the Ub to find to during the ubiquitination process? Is there a free lysine ...