Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

1
vote
1answer
20 views

Which molecule that an excess of inhibits B-oxidation?

Which molecule that an excess of inhibits B-oxidation? a. Acetyl-coA b. Malonyl-coA This question is so debatable, because both are correct However, according to my professor, only one is ...
1
vote
0answers
14 views

Antigen molecular mimicry

Let us consider a situation in which the body is attacked by a microbe, and the microbe is captured by the immune system for recognition of surface antigens. The surface antigen recognized mimics one ...
2
votes
1answer
29 views

Is studying chemical and physical properties of chemical substances that make up organisms really a task of molecular biology?

I have read in a high school textbook that (translated into English by myself): "Branch of science that concerns itself with studying chemical and physical properties of substances that make up ...
0
votes
0answers
12 views

How efficient is direct cloning in budding yeast?

I am trying to make a clone using E.coli as host and use that clone later to transform budding yeast. But, I am not able to get clone somehow so I was wondering to perform lithium acetate ...
-4
votes
0answers
22 views

What chapters from the Campbell Biology 11th edition textbook are covered in the AP Biology curriculum/exam? [closed]

I am currently taking College Biology in high school but I plan to take the AP exam in May. The syllabus for my class skips a lot of the chapters in the Campbell Biology textbook. I would like to know ...
1
vote
1answer
15 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 ...
1
vote
0answers
15 views

Can we spike with a different enzyme to a SYBR Green Master Mix?

I followed the standard SYBR Green Protocol for doing a qPCR. For which I used 10 uL of 1X SYBR Green Master Mix Forward Primer and Reverse Primer (each at a final conc. = 8.5 uM) Template (unknown ...
-2
votes
0answers
31 views

Reproduction - can we say that the rejuvenation is not miracle and the Nature is doing it constantly? [closed]

I am big fan of rejuvenation and indefinite life extension - there are good research along these lines, e.g. http://www.sens.org/research/introduction-to-sens-research/extracellular-junk (the best, ...
0
votes
1answer
34 views

Barr body. How does it work?

Barr's body is a spiral X chromosome. If I'm not mistaken, one random chromosome (a healthy woman) is inactivated in each cell. Which X chromosome is inactivated in a given cell is random. I've heard ...
2
votes
1answer
43 views

Why is Turner's syndrome a problem?

So Turner's syndrome is a chromosomal defect where one of the X chromosomes is missing. For more details visit the [Wikipedia page] (https://en.m.wikipedia.org/wiki/Turner_syndrome). But I don't ...
1
vote
1answer
19 views

Design rules for DNA linkers

I want to use double stranded DNA linkers to physically bind two "things" together, by grafting ssDNA on each one of them and using DNA hybridization as the locking mechanism. I do not expect the ...
9
votes
1answer
87 views

Why don't the heads of phospholipid bilayers repel hydrophobic molecules?

What I Think I Know: Hydrophilic and hydrophobic things repel each other. Since the cell membrane contains hydrophobic tails, it is difficult for hydrophilic molecules to pass through the cell ...
1
vote
1answer
35 views

What would “N” and “V” stand for in DNA barcoding?

I'm currently looking protocol for PAT-seq, and when it talks about the barcoding that's utilized, the documentation mentions there being an "N" and "NN" in the sequence, as well as a "V". For example:...
5
votes
2answers
83 views

Are redundant codons used in translation?

I am learning about redundancy in genetics and I came across this statement in my textbook: more than one codon for an amino acid means that some codons are redundant - the process of protein ...
-1
votes
0answers
22 views

(Reliable Source Needed): Why is the phospholipid membrane more permeable to hydrophobic molecules?

It is often said that it is difficult for hydrophilic molecules to pass through the phospholipid bilayer because of the hydrophobic core. However, it would seem logical to assume that it would also be ...
1
vote
1answer
18 views

Will DNA nanostructures be useful for medical applications?

There is a lot of work being done on developing small nanomechanical structures and even small nanomechanical actuators built with DNA. I have heard researchers motivate this research with claims ...
1
vote
0answers
14 views

How does Ran GDP get from the cytoplasm back to the nucleus following nuclear import and export?

I understand that in Ran-dependent nuclear import Ran GTP binds importin in the nucleus, and after diffusing through the nuclear pore complex Ran GTP is hydrolyzed to Ran GDP and releases importin. ...
1
vote
1answer
25 views

What is trans-complementation?

Is trans-complementation a complementation of transgenes? The crystal structure reveals a trans-complementation mechanism whereby an incomplete immunoglobulin-like domain assimilates an isoform-...
50
votes
4answers
8k views

What is the longest-lasting protein in a human body?

Protein life times are, on average, not particularly long, on a human life timescale. I was wondering, how old is the oldest protein in a human body? Just to clarify, I mean in terms of seconds/...
0
votes
1answer
27 views

Why are there inverted repeats in response elements?

The following picture shows an inverted repeat sequence in a response element. Response element sequences for glucocorticoids, estrogen, and thyroid hormone show that they all contain inverse repeats. ...
0
votes
1answer
19 views

Hydrophobic interactions in the helix-turn-helix

This slide states that the second helix works to stablize the configuration of the two helixes via hydrophobic interactions. What exactly is this hydrophobic interaction? In other words, what ...
0
votes
0answers
7 views

Cell wall constitution of Schizosaccharomyces pombe

where is located the 1,3-α-glucan in the cell wall of Schizosaccharomyces pombe? Is it in the inner or outer layer? Thanks
1
vote
1answer
53 views

Protein electrophoresis

Three proteins A, B and C of equal molecular weight are being investigated in a study. They contain six, four and four cysteine residues respectively. Only Proteins A and B were treated with β-...
1
vote
2answers
55 views

Name of dsRNA (or dsDNA) where all strands are identical

What is the name of dsRNA (or DNA) where all component strands are identical (i.e. where the complex consists of multiple copies of the same ssRNA)? Example: 2 identical ssRNAs forming a dsRNA ...
1
vote
0answers
29 views

Does every protein encoding gene necessarily have a transcription factor?

For instance, transcription factor gene A is responsible for activating gene B that encodes protein 1. However, it is possible for genes like gene B to encode proteins without having transcription ...
2
votes
2answers
150 views

What makes/breaks the hydrogen bonds between DNA and RNA during transcription?

So I know that RNA polymerase catalyzes the phosphodiester bonds that hold the sugar backbones of a growing mRNA molecule together during transcription. However, I'm less sure about the hydrogen bonds ...
0
votes
0answers
10 views

What's the difference between beta thalassemia minor and beta thalassemia intermediate?

I mean beta thalassemia minor is caused by inserting one abnormal allele while beta thalassemia intermediate is when the person has at least one B+ allele. Is beta thalassemia intermedia a type of ...
0
votes
0answers
29 views

Questions to protein folding

I have some questions regarding the process of Protein folding. These are the following: Are there existing Protein folding processes, where only a few seconds after completed folding a Protein ...
0
votes
1answer
59 views

Does the deletion of Chromosome 20 cause immunity against prion disease?

I was reading recently about prion disease and it caught my attention that a normal prion protein is coded n chromosome 20, therefore, in order for an infectious prion protein to attack, there must be ...
2
votes
1answer
31 views

What does it mean to use DMSO as a dissolvant in biology experiemnts?

In many biology publications, I saw that dimethyl sulfoxide (DMSO) is used to dissolve drugs. However, the cell-based assays are still performed in water-based medium such as RPMI or PBS. My ...
-1
votes
3answers
79 views

You need DNA to make RNA, and RNA to make DNA, so they had to come into existence at the same time?

A statement I recently read: 'Evolution is debunked and gives no basis for morality. Natural Selection throws away info, it does not add. You need DNA to make RNA, and RNA to make DNA, so they had to ...
2
votes
1answer
39 views

How to find idea for essay [closed]

I'm studying microbiology in Iran The university that I'm studying in doesn't provide that much help in research areas and we don't get to research or write essays that much ,while I'm trying to write ...
1
vote
0answers
30 views

Fruiting of trees — environmental stimuli and biochemical cascades

My question concerns fruiting of trees in general. However, I live in a tropical country (Philippines) where mango trees are ubiquitous, so I'll use it in stating my question. The question is about >...
0
votes
0answers
19 views

How the albumin regulates osmotic pressure

Do I understand correctly that: When albumin binds non-water molecules to itself, the concentration of non-water molecules decreases, thus the osmotic pressure decreases; When albumin carries water, ...
2
votes
0answers
54 views

Why does M1 RNA together with C5 protein in 100mM Mg(II) fail to cleave tRNA?

Sidney Altman discovered that RNA moeity of RNAse P (M1 RNA) alone is able to perform enzymatic cleavage of ptRNA, which won him the Nobel Prize of Chemistry in 1989. However, when I read the Nobel ...
3
votes
2answers
94 views

Chemistry of phosphodiester bond formation by DNA polymerase

As I'm teaching General Biology to my college students, I realized that I don't fully understand how a 3-P nucleotide like ATP is broken down to be incorporated into DNA during replication. How does ...
0
votes
1answer
79 views

Is one STR be enough for a reliable identification in real life?

The lab simulates the analysis of just one STR in the genome. Would this analysis be sufficient for a reliable identification in real life? If not, explain what could be done using DNA to identify ...
0
votes
0answers
20 views

How do Introns in pre-mRNA interrupt gene transcription?

This is stated as obvious in one of my textbooks. Can anyone explain how this works ? How does a product of transcription interrupt transcription ? Picture to demonstrate. Legend: E: Exon ...
0
votes
1answer
22 views

Biology and dna samples to determine parental lineage [closed]

How could you use nuclear and mitochondrial DNA samples run through electrophoresis to determine parental lineage.
0
votes
1answer
36 views

How is the timing of gene expression controlled in developing embryo? [closed]

I understand how cell differentiation works in general (gradients of homeobox proteins etc), but how is timing controlled? Why do some genes switch on at a very specific moment of development and then ...
0
votes
1answer
23 views

Insertion Confirmation Cloning Strategy

So I am in a bit of a time constraint. Essentially, I inserted a DNA fragment via molecular cloning which contains a unique RE site. I need to confirm whether my colony has or does not have the ...
0
votes
0answers
20 views

What conclusions can I draw about the size, charge, and shape of messenger molecules?

Molecules such as cAMP or Inositol trisphosphate are used in organisms as messenger molecules that make things happen when they are supposed to happen. These molecules are usually big, but not too big,...
0
votes
0answers
25 views

What do halophiles eat?

We all know that halophiles can survive salt environments and all that, but what do they really eat? Do they consume the salt in their habitat?
10
votes
3answers
540 views

Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

One of the major results of the Human Genome Project (HGP) was that humans have far fewer separate genes than previously thought. From a 2004 article about the HGP: Francis S. Collins, director of ...
0
votes
0answers
17 views

Is there a good source for detailed molecular/atomic information about plant cells?

Can anyone point me to a good source for understanding the molecular/atomic details for the structure of a plant cell? For each element of the plant cell, I want to know what kinds of molecules/atoms ...
1
vote
1answer
30 views

identification of differentially expressed genes in RNA-seq analysis

I am using four different packages (viz. EBSeq, DESeq2, edgeR, LPEseq) for identification of differential genes. Now I am confused whose fold change value should I take for further downstream ...
2
votes
2answers
74 views

How do I calulcate the amount of concentrated stock solution to add to get the correct dilution?

For example, how much loading buffer (6X) do I need for my PCR reaction with a volume of 25 μl? What is the general way to calculate it?
0
votes
1answer
57 views

How can two biological sequences be anything but homologous?

If we consider homology between two nucleotide sequences as a yes/no answer to whether they have shared a common ancestral sequence, then given that all life share common ancestry and sequences are ...
0
votes
0answers
13 views

Meting temperature of PCR products and product expected size

I know the Melting temperature of my primers but I would like to know if the melting temperature of my product match with the melting temperature I get in the melting curve when doing a qPCR, in order ...
1
vote
1answer
28 views

What does “novel, predicted deleterious, within autozygome” mean in genetics?

I am a medical student and just got involved with a genetic lab and research. I read a lot phrases like: "Although no mutations have been reported in this gene, we think this variant is interesting ...