The study of chemistry within the scope of biology: the compounds that occur and the reactions involving them in living organisms.

learn more… | top users | synonyms

0
votes
0answers
12 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 ...
0
votes
0answers
7 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 ...
1
vote
1answer
23 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 ...
14
votes
4answers
3k views

What implications has the missing 2'-OH on the capability of DNA to form 3D structures?

The chemical difference between RNA and DNA is the missing 2'-hydroxyl group in the nucleotides that build DNA. The major effect of that change that I know of is the higher stability of DNA compared ...
0
votes
0answers
17 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
votes
0answers
14 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, ...
5
votes
1answer
42 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?
1
vote
0answers
20 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 ...
1
vote
2answers
324 views

What is the importance of urea in mass spectrometry?

What is the importance of urea in mass spectrometry? We use 8M urea to FASP our proteins prior to mass spectrometry. What is the significance of using 8M urea? and how does it affect the proteins?
0
votes
1answer
31 views

Find the concentration of free receptors in a solution of 90% free ligand and 10% receptor-ligand complex, knowing only the value of kD

I could use some guidance on how to utilise the equation for the disassociation constant kD to find the concentration of free receptors [R] in a solution containing 90% free ligand [L], and 10% bound ...
0
votes
0answers
8 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 ...
4
votes
1answer
88 views

Synthesis of Fatty Acids Longer than 16 Carbons

I understand that the human body when performing Fatty Acid Synthesis can synthesize only until C16 (palmitate). However the ER has desaturases and elongases. I know that desaturases are used to add ...
0
votes
0answers
16 views

Why would the presence of two Lys groups near the amino terminus destabilize alpha helix? [closed]

I'm going through this practice exam and I ran into this question. "Why would the presence of two Lys groups near the amino terminus destabilize alpha helix?" Why would a basic amino acid interact ...
3
votes
2answers
95 views

Light and Dark Reaction of photosynthesis?

I'm having a hard time understanding light and dark reactions because all the sites I've gone through provide different equations. Some say photolysis is H20 = H+ + O2 while some present it as H20 = ...
1
vote
0answers
27 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 ...
0
votes
0answers
11 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?
2
votes
0answers
20 views

Does alpha-amylase from different species have different *optimal* conditions?

Do the optimal conditions for the enzyme isoforms differ between species? Specifically, do the optimal pH and temperature for alpha-amylase differ for that enzyme produced by B. lichiniformis and A. ...
0
votes
1answer
32 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 ...
4
votes
1answer
2k views

Which are mobile and immobile elements in plants?

I am confused with this element or nutrient classification in the plants, since some authors set elements like $\ce{S}$ and $\ce{Ni}$ as mobile and other as immobile elements (Citation 1, 2, 3, 4, 5). ...
7
votes
1answer
199 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 ...
0
votes
0answers
29 views

Why are amides transported via xylem vessels? Why not phloem?

There is a statement in my textbook: "since amides contain more nitrogen than amino acids, they are transported to other parts of plants via xylem vessels" I wanted to know why the book ...
0
votes
1answer
25 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 ...
2
votes
1answer
64 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
votes
1answer
35 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 ...
0
votes
0answers
57 views

What is the Ramachandran z-score of a denatured protein?

I thought it should be 0, but the professor pointed out I was wrong. What should the Ramachandran z-score of a denatured protein be?
11
votes
1answer
328 views

What is the transmembrane 'Positive-Inside Rule' nowadays? Has the definition changed over time?

First definition. Two publications by von Heijne in 1989 and 1992 coined the 'Positive-Inside rule' and showed it's practical value in topology prediction of transmembrane helices. It was clearly ...
0
votes
0answers
10 views

Bence-Jones proteins in urine on heat

The preliminary test for proteinuria is precipitation/turbidity on heat due to denaturation. This turbidity should not disappear when 10% acetic acid is added - to differentiate from phosphates. ...
4
votes
2answers
177 views

Are Gram negative bacteria classified as such because of their negative membrane potential?

Does the membrane potential usually quoted for Gram negative bacteria (e.g., E. coli) refer to the potential across both membranes? - If yes, then does the potential fall more over the inner or outer ...
1
vote
1answer
58 views

Which organisms have their cell wall made of polysaccharides and amino acids?

I came across a question which somewhat goes like In which of the following kingdom, most of the members have a cell wall made of polysaccharide and amino acids ? - Monera or Fungi. To me it ...
8
votes
1answer
508 views

What is the difference between organelle membranes?

Cells and organelles are contained in lipid bilayers. I'm particularly interested in eukaryotic organelle bilayers and the biophysicochemical differences between them. Many papers assume a ...
1
vote
1answer
36 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
0
votes
0answers
38 views

Link between NaCl and sulfide reducing bacteria

Could there be any link between the consumption of NaCl and sulfide-reducing bacteria? In my study on mice, sulfide-reducing bacteria (SRB) are more abundant, in high-salt-fed group compared to the ...
1
vote
2answers
462 views

Can excessive carbonated drink consumption lead to elevated red blood cell levels?

I've recently had a blood test and the results displayed elevated levels of erythrocytes as well as hemoglobin. (As a result my hematocrit levels were also above average) At my workplace there is a ...
0
votes
1answer
40 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 ...
2
votes
2answers
124 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 ...
1
vote
1answer
26 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 ...
8
votes
1answer
6k views

What is/are the molecular differences between HDL and LDL cholesterol?

Why exactly is HDL-cholesterol good for us and LDL-cholesterol bad for us. It has been well-established that LDL-cholesterol is associated with atherosclerosis and that HDL-cholesterol helps remove ...
0
votes
0answers
21 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 ...
1
vote
1answer
57 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 ...
5
votes
1answer
69 views

How are ions 'pumped' across a membrane during electron transport?

A number of sites (including this one) that provide descriptions of photosynthesis state that high energy electrons 'pump' ions across a membrane. What is the actual 'pumping' mechanism? I've looked ...
1
vote
1answer
51 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 ...
2
votes
1answer
54 views

Difference between the P4 and P5 subtypes of P-type ATPases in plants

In plants there are various kinds of P-type ATPases. What is difference between P4-ATPase and P5-ATPase?
0
votes
2answers
93 views

What makes something food?

From my (limited) understanding, animals get energy from food by breaking chemical bonds between molecules. There's a lot of water here [citation needed], so it seems like natural selection would ...
14
votes
2answers
6k views

How does a plant grow before photosynthesis is possible?

During photosynthesis, a plant translates CO2, water and light into O2. I assume the carbon C is further used for the growing process. I wonder how the plant grows before the time where photosynthesis ...
0
votes
1answer
142 views

Does the use of RNA as a primer affect the accuracy of DNA replication in E.coli?

DNA polymerases have proof-reading ability, but RNA polymerase does not. Does the use of RNA as a primer affect the accuracy of DNA replication in E.coli? Explain
0
votes
1answer
25 views

Enzyme kinetics: recommended literature to grasp the concepts better

I have had a few biochemistry courses, but I still feel confused and a bit scared each time they try to explain and apply enzyme kinetics or even chemometrics in different situation during class. On ...
3
votes
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 ...
0
votes
2answers
69 views

Can photosynthesis take place if the plant is kept in ice cold water or not?

Can photosynthesis take place in a plant even if the plant is kept in ice cold water? I have googled this question, but so far have not found a satisfactory answer.
1
vote
1answer
30 views

meaning of arrows in a 3D biomolecule representation

I would like to know what those arrows and also thin wires between them in this cd4 biomolecule's 3d representation mean. Thanks in advance.
1
vote
1answer
41 views

In flowering plants food is transported in which form? [closed]

In flowering plants food is transported in which form? I searched on google and found that it is sucrose. Why not glucose/fructose/starch?