The study of cells: their physiological properties, structure, environmental interaction, division, life cycle, and death, as well as the organelles they contain. Also known as cytology.

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241 views

Consequence of touching Formaldehyde

I accidently touched formaldehyde some days ago. Skin on my hand got dehydrated as if I had placed it in salt solution. I washed it with water and it returned to normal state after 5 minutes. But now ...
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109 views

Functioning of EDTA

I know that EDTA chelates metal ions. It weakens bacterial cell wall and inactivates the DNases. What is the reason why it can do so ? I guess it can inactivate DNases by altering the ...
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68 views

Structure of biological membranes?

Integral membrane proteins have functional asymmetry i.e. they have two different domains of proteins performing different functions. these proteins have Tyr and Trp amino acid residues at the ...
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231 views

What causes Paresthesia (Pins and Needles) at a cellular level?

I've looked it up in plenty of places like the Wikipedia page and such, and it is clear that the most common cause of Paresthesia is either a fair amount of pressure on a specific patch of skin ...
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1answer
47 views

Sodium-Potassium Pump

From my understanding, in the sodium-potassium pump we have Na+ inside the cell and K+ outside the cell, thus forming a so called "salted banana." After reading my textbook I found many statements ...
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79 views

Hela live cell confocal laser scanning - reccommendations for good fluorophore that will show good movement

I've been doing a lot of live cell imaging lately mostly using hela cells expressing some EYFP based chimeric proteins. I'm building a video library for an art student here at the university who is ...
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412 views

What kind of a microscope do I need to see cell organelles?

I would like to study cells and looking for a microscope that would allow me to see: groups of cells individual cell cells organelles I would like to target insects and mammal tissue. I would be ...
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1answer
36 views

What can thrombosis lead to?

I am thinking this question. Thrombosis can result in organisation of thrombus, sepsis thromboembolism, fibrinoid swelling adiposity. I fibrinoid swelling (edema) (4) can occur. Also, I think (3) ...
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1answer
281 views

How does a fertilized egg form 23 pairs of chromosomes?

I am always confused about this...so when one cell which has 23 pairs of chromosomes undergoes the two meiotic divisions it produces four cells containing 1 chromatid of every chromosome pair so when ...
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672 views

Why do cells vary in shape and function when they have the same genome and the same organelles?

Why do cells vary in shape and function when they have the same genome and the same organelles. For example: why do all cells have nuclei but red blood cell's don't; why can't the cells of a eye ...
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51 views

How do mosquitoes maintain telomere length?

While the vast majority of eukaryotic organisms maintain their chromosome ends (telomeres) via telomerase, an enzyme system that generates short, tandem repeats on the ends of chromosomes, other ...
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163 views

MTT assay normalization

Since the precise amount of cells in each well of an MTT assay varies, how can I normalize the results by cell number/concentration? How can I take into account the number of cells that have already ...
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0answers
43 views

Nearly Exhaustive List for Cholesterol Pathways [closed]

I have run across an interesting case that is similar to only two others I've encountered. What makes it interesting is the combination of undetectable (under normal testing conditions, can elaborate ...
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1answer
54 views

how cells make other macro molecules?

We know that the nucleus of the cell is the White House of the cell and its DNA is the president and it commands to make protein. So my question when DNA only codes for protein and enzymes,after the ...
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75 views

Gap junction turnover

Gap junction proteins, connexins, are known to form intercellular hemichannels, between two adjacent cells. These junctions are maintained cell adhesion proteins (cadherins), yet the turnover of ...
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1answer
32 views

What are the effect of microtubule or microfilament inhibition on yeast expression profile?

I was wondering whether anyone has looked at what are the expression changes in yeast when the microtubule or the microfilament polymerization is inhibited? Have there been whole-genome studies?
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2answers
2k views

Explanation of the terms “downstream signaling” and “upstream signaling”

In molecular biology, what's the meaning of the terms "downstream signaling" and "upstream signaling"? What's the difference between them?
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237 views

Benefits of CLARITY?

What are the benefits of CLARITY over this technique that was published more than a year earlier? Of course the second technique needs a fancier microscope that is likely more expensive and requires ...
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85 views

Diffusion of FAD+

Why is NAD+ free to diffuse within the mitochondrion whereas FAD+ is not ? What biochemical properties cause this difference ?
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76 views

Why is succinate dehydrogenase attached to the inner mitochondrial membrane?

Succinate dehydrogenase is attached to the inner mitochondrial membrane.All the other enzymes of the Krebs cycle are located in the matrix of mitochondria. What is the biochemical reason behind ...
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211 views

Microtiter Dish Biofilm Formation Assay- Pseudomonas and Crystal Violet

If Pseudomonas is a gram negative bacteria, it does not retain crystal violet but why is it that so many people are using crystal violet staining in theri Microtiter Dish Biofilm Formation Assay?
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2k views

Rate of cell division in humans

On average, how many cells divide each day in a human being? How long does a cell wait before dividing itself ? I have tried to look on the internet but surprisingly the answer is difficult to ...
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1answer
144 views

Solubility of Forskolin in ethanol

I am interested in using forskolin in cell culture medium. Does anyone know how to make solution of 10 microM forskolin in 5% ethanol or less. I would like to avoid using DMSO as a solvent. Thank you. ...
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2answers
142 views

Smoking, cancer, correlation between quitting smoking and increased immediate risk

There is "proof" out there today that suggests smoking is directly linked to cancer. I cannot argue against that, for the evidence in favor appears strong, and the evidence against is lacking. I'll ...
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504 views

Natural examples of XOR functions at the cellular level

We can often think of cells as a sort of circuit on macromolecules, and can show that they can accurately and robustly implement functions like $\text{MAJ}(x_1,...,x_n)$ (return $1$ if more than half ...
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36 views

Dinuclei cellular mechanism

I am no biologist, but I have this question buzzing in my mind. It's a matter of curiosity What happens when two nuclei occupy the same cell? Would we expect the embryo (if it lives) to have complex ...
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428 views

What is splice junction pairs?

Splicing is a modification of pre mRNA when all introns are removed and exons are joined. What is a splice junction pair? It is two exons which connected together?
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57 views

How many chemical species are on average in a typical plant and animal cell?

I want to know what sort of range there is on the number of different chemical species in a typical plant and animal cell. Failing that, some specific examples (with sources please). Thanks
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154 views

How many centrioles/basal bodies are there in multi-ciliated cells throughout the cell cycle?

I thought there were only two centrioles per cell, that convert to the basal body at some point during the cell cycle. I also thought there's one basal body per cilium, so I'm not clear on where the ...
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351 views

Which of the cell types commonly found in mammals has the greatest number of mitochondria?

This is basically a fun question, inspired by this answer on scifi.se. So, which cell type will have the greatest number of mitochondria? Obviously, I am talking about wild type, healthy individuals ...
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63 views

Referencing the homologous chromosomes

There exist a co-ordinate system from chromosomes like "12p11.3". In this system, first integer range from 1 to 23 i.e it takes homologous chromosomes as a pair. If we want to distinguish among ...
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2answers
62 views

Connection between genes and pathways

I am reading about a paper about inferencing pathway information in cancer cells. Authors refer to ERBB2 as a gene and a pathway. I don't have solid biology background. What exactly means when we ...
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183 views

How does human body deal with inert solid material in the bloodstream?

How does human body deal with inert solid material in the bloodstream? For example, if there is a powder of glass injected into our bloodstream, will the white blood cells do anything or will kidney ...
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1answer
142 views

What are the lifetimes of cellular components on organelle or molecular level?

I was thinking that even though I know how generally the cell works, I don't really have a feeling of how volatile it is. I want to know what is the lifetime/turnover rate of different constituents of ...
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517 views

The Origin of Mitochondria

For a long time I've just accepted, because it is just what everyone told me, that mitochondria became organelles in the cell when they were "engulfed" by another cell which acted like it's host. This ...
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389 views

Aerobic vs anaerobic respiration comparison

The following graphs compare glucose decomposition in yeasts (in anaerobic vs aerobic conditions respectively) My question is, why doesn't the first one look like a straight line as the second one ...
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127 views

What is the smallest oligocelluar organism?

What is the smallest oligocelluar organism? How many cells does it have? EDIT The question is motivated by this comment@Philosophy.SE EDIT as recommended in comments I'm looking for an example of ...
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2answers
180 views

How do detergents get in hydrophobic membrane interior?

According to Molecular And Cellular Biology (Stephen L. Wolfe), Membranes disperse almost instantaneously if exposed to a nonpolar environment or to detergents, which are amphipathic molecules ...
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1answer
89 views

What is a phospho-protein binding domain?

Is this just a domain that binds proteins that have been phosphorylated? And it mediates signalling between an activated/phosphorylated protein? How is this significant with BRCA1?
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176 views

Photosynthesis: Splitting Water

The splitting of water is an endergonic (non-spontaneous) reaction, and thus would require energy (chemical work to be done) in order to happen. In Photosystem II, an enzyme catalyzes this splitting, ...
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1answer
56 views

Looking for raw cell videos from a light microscope

First off, I'm not looking for online lectures. I am trying to find creative commons licensed videos of live cells moving around without annotation or anything extra. I would prefer a few minutes of ...
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2answers
2k views

Cell life: division for immortality or reproduction with aging

Are the two cells that are derived from one cell, ‘twin sisters’ or a ‘mother and a daughter’? In other words, can a cell really be divided to live an "immortal" life or is cell reproduction the ...
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262 views

Time spent in phases of cell cycle

I am looking for references to papers containing the time intervals spent in different phases of the cell cycle (ej., G0, G1, S, G2, M for eukaryotes) for different cells. In particular, I am ...
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1answer
80 views

What's a replicate line?

The methods section inside a paper I'm reading make mention of replicate lines. Example: "We founded 10 replicate lines from a single clone". This is in the context of experimental evolution and ...
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4answers
2k views

Why would a single celled organism evolve to be multi-celled?

I read a story this week on Richard Lenski who has been 'evolving' E. coli for more than 50,000 generations now. One comment I read was from someone who doesn't accept Evolution who pointed out that ...
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1answer
363 views

How much does the Hayflick limit/telomere length vary across taxa and within humans?

Since they seem to be quite connected, I'm curious if anyone knows of research comparing the Hayflick limit (and presumably by extension telomere length) between different taxa. I've heard the ...
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1answer
156 views

Why are transmembrane proteins difficult to crystallise?

I know that in vivo there are a lot fewer transmembranous proteins in general, and that they are produced at a lower rate than their free counterparts. This is mainly because transmembrane proteins ...
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1answer
94 views

What will happen if we expose the brain to an intermittent light?

If a brain is exposed to an intermittent light are specific areas going to fire? If yes, which of them? Is there any experiment about this?
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2answers
307 views

Homework : Sodium Potassium pump

Why does sodium-potassium pump consume about 2/3 energy of a cell ? A.maintains appropriate membrane potential B.helps in co-transport I think it should be A.
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1answer
87 views

Body's decomposition

Does a human body decompose in a completely sterile environment ? If yes, what decomposes it ? And how fast ? What happens in vacuum ? Can it remain exactly the same ? Thanks