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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Mitochondria - are they really separate organisms that once merged into eukaryotic cells?

Theoretically, mitochondria are said to be a separate organism that is concerned with its own life and its own processes. In fact, it even duplicates individually. I know a similar question is here ...
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55 views

Where can I find a full genealogy of human cell types?

It is said on Wikipedia, that the precursor of blastocyst is a morula, and that the precursor of morula is a zygote. This gives us the part of genealogy tree of cell types. Unfortunately, no full ...
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170 views

How did viruses learn to utilize the workings of a cell?

This is my first post here, so excuse me for its simplicity. Viruses can infiltrate a cell, overtake it and multiply. It has projecting fibers whose ends are shaped as kind of a "key" to a mobile ...
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102 views

What are the different, high-level programs along which a eukaryotic animal cell can follow?

What are the different, high-level, disjunct (mutually exclusive at one particular point in time) programs or pathways along which a eukaryotic animal cell can follow? Examples of programs would ...
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How long can a unicellular organism live without nutrition? What happens after that? Does it depend on the domain?

Say I have three unicellular organisms: a eukariote, a bacterium and an archaeon. If I cut off nutrition from them at the same time, how long will it take for them to die? What will their death look ...
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59 views

NADH shuttles - Why cytosol?

Why is the malate-aspartate and the glycerol-3-phosphate shuttles located in the cytosol and intermembrane space? The krebs cycle happens in the matrix so why wouldn't they push electrons from the ...
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440 views

How is excretion of metabolic wastes from a cell related to its size?

As with anything that is taking place within a cell, the metabolic waste too must be proportional to the size of the cell. In particular the surface area to volume ratio. But how is the waste ...
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Can bioluminescence be used for cancer or tumor detection? [closed]

What diagnostic applications, if any, are there in using bioluminescence to detect cancer or tumors (in vivo)?
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163 views

Which of the two mitochondorial membranes relate to bacteria according to the endosymbiotic theory?

I seached for endosymbiotic theory in Wiki and I found this about endosymbiotic theory: Symbiogenesis, or endosymbiotic theory, is an evolutionary theory which explains the origin of eukaryotic ...
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103 views

Energy metabolism in Cancer cells

The TCA cycle intermediate Isocitrate dehydrogenase commonly undergoes point mutations in cancers. This allows IDH to reduce a-Ketogluterate to 2Hydoxygluterate, causing a reduction in pVHLs ability ...
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96 views

PSI-BLAST website algorithm parameters

http://blast.ncbi.nlm.nih.gov/Blast.cgi In this website, when I want to apply the psi-blast algorithm on a sequence, under the section of algorithm parameters , what does PSI-BLAST threshold mean? ...
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113 views

Integration of several environmental signals

I am looking for examples of different functions that are good fit to how signals are computed in order to respond to the environment. Let's make my question more copmrehensible with an example... ...
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Has an artificial symbiotic relationship ever been created?

Have 2 organisms ever been introduced to create a symbiotic relationship that doesn't occur in their natural environment?
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25 views

Polarized epithelium and localization of ion channels

I'm trying to learn more about polarized epithelial cells of the gut. I am familiar with classic brush border transporters localized to the apical memebrane to facilitate nutrient absorption. I am ...
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129 views

Amino acid profile of GPCRs

You are studying cellular signalling through a newly identified GPCR. Specifically you’re working on a pair of newly identified GPCRs, GPCR-A and GPCR-B. Each binds the same small ligand, but ...
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318 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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232 views

Why are centrioles aligned at 90 degree with each other?

The centrioles are aligned at 90 degree with each other. What is the function of this?
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307 views

Why did Fair Meiosis evolve?

How and why did Fair Meiosis evolve? I can hardly think that it provided a fitness advantage to the individual carrying the mutation. Why would it? Or did it evolve through lineage selection? Or was ...
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6k views

Why do cell membranes have a lipid bilayer?

Many cells have a cell membrane composed of two layers of lipids, why is it two layers and not just one? What purpose do the membranes serve?
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175 views

How do different tissue culture matrices affect background in fluorescent microscopy?

In response to my previous question, I've been reading up a little bit on poly-D-lysine, Collagen I, Collagen IV, laminin, and other tissue culture coatings that promote cell adhesion. I've always ...
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204 views

What molecular processes are involved in pseudopodial extension?

I am curious as to the processes and mechanisms involved in the extension of pseudopodia in amoeba. How does the cell know and control the direction and extent of pseudopodia formation at a molecular ...
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1k views

“Acellular” designation for organisms

Why do some biologists refer to single-celled organisms such as Amoeba and Paramecium as acellular (i.e., without cells) rather than unicellular (i.e., one cell)?
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50 views

Could a single cell be brought to life?

If a scientist is observing a single cell under a microscope, and then realizes that the cell has died, is it possible to bring that dead cell back to life? For my inquiry, let's assume that the ...
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40 views

Can a cell start a mitosis if it lacks energy or molecules to complete it?

I'm wondering whether a cell can start a mitosis if it lack molecules or energy to fully complete it. From what I'm reading on wikipedia the cell passes most of its time in the interphase in which the ...
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29 views

What is the purpose of requiring two separate binding systems for the antibody response?

I've read that in most cases, B-cell activation requires helper T-cells. This requires antigen binding by both antibodies and T-cell receptors, using two different antigen-binding proteins, ...
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32 views

Where exactly is 'Colloid' with regards to synthesis of thyroid hormones?

I've researched colloid and it seems to be a substance of microfibres and thin films in which thyroid hormones may be synthesised, but I was wondering where this exactly is... I think it could be in ...
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151 views

How does Cro protein expressed by lambda phage kill its host?

I read that the DNA segment of lambda phage integrated in host DNA could switch between lysogenic state where cI represses the expression of Cro and lytic state where Cro expression takes over and ...
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69 views

What happens to the excess immune cells or WBC in our body?

When we have an infection our immune system produces a large amount of white blood cells (WBCs) in our body to fight against the pathogen or parasite. My question is after the immune response has ...
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151 views

What is a functional screen?

I was going through this paper, but did not understand a term. What is the meaning of functional screen? (I am not a biology student, I don't understand much, and a small simple explanation would ...
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278 views

How did the endoplasmic reticulum come to be?

Organelles are sub-cellular compartments in cells. However prokaryotes don't use organelles to organise their intracellular space. Evolutionarily, there is evidence that mitochondria and ...
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98 views

Microalgae without cell walls?

Most microalgae have rigid cell walls. Dunaliella Salina is a pretty famous example of an algae with no cell wall, but just a plasma membrane. Are there any other microalgae without a cell wall?. I ...
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72 views

Mechanisms of bone growth

The length of a bone is caused by growth of hyaline cartilage which is then replaced by bone tissue. How do cells know whether they should grow the hyaline cartilage? What are the key molecules that ...
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63 views

How does one determine intracellular concentration?

The TL;DR version Is there a fast way to determine what the cell environment of a particular cell (E.g RBC) is? (in terms of solute/ionic concentration) I'm not sure if the question belongs here, ...
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97 views

SEREX serological analysis of cDNA expression library

What is Serological Analysis of cDNA expression library? I went through this article:http://cancerimmunity.org/serex/introduction/ but could not really make out. Can someone please explain this to me ...
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69 views

How is the growth of benign tumors suppressed?

A benign tumor has an outer layer of cancerous cells beyond which are regular cells (I Think). The Tumor must have some kind of boundary layer like a wall where somehow the cancerous cells can't ...
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87 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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68 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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1k views

How does formaldehyde/PBS or methanol fixation of cells affect lysosomal pH?

The question is fairly simple - does formaldehyde or methanol fixation in preparation for immunocytochemistry/immunofluorescent staining affect the pH of the lysosomes? Some background: I'm trying to ...
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304 views

What is range of the number of individual organelles in cells

What is the range of the number of individual organelles in a cell? I am not a biologist but I understand that there's one nucleus and sometimes lots of mitochondria, so I am after the total number. ...
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49 views

HOw are AMP's “recharged” to become ATP's in a cell?

I understand that after the translation stage of ribosomal protein synthesis, tRNA molecules are floating in the cytoplasm without attached amino acids until they find the correct aminoacyl tRNA ...
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58 views

Purpose of antibody wash

It is common practice after surface staining cells for flow cytometry analysis to wash the antibody out of solution before analyzing a sample. I have tried analysis with and without washing the ...
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1k views

Is the ringing sound in the ears caused by dying ear cells?

I was recently watching the movie "Children of Men" (great movie) by Alfonso Cuarón. Now in a certain scene, the lead actor happens to be nearby a loud explosion. Later, when he complains about the ...
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97 views

Expression/Mechanism of ROR1 in healthy tissue

ROR1 is currently under investigation as a therapeutic target for cancer (1). A number of studies show different cancers may have their metastatic potential reduced, or become apoptotic through ...
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50 views

Estimating RPM to RCF in Methods from Older Papers

I'm attempting to replicate a cell biology method from a 1958 Laboratory Investigation paper. The protocol is for the isolation of an extracellular matrix protein, and a key step is a centrifugation ...
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52 views

Prevent biofilm formation on moist surfaces

I have an indoor fountain with lots of water. What are the most common microorganisms in this kind of moist environment, and what are the standard way to prevent biofilm formation by them? I thought ...
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2answers
169 views

How does the cell regulate different metabolic pathways?

I heard somewhere that cells use different nucleosides bound to triphosphates e.g. ATP, GTP, CTP and other modified compounds: NADH, NADPH to distinguish between different metabolic pathways and so ...
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243 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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114 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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1k views

How does sugar enter neurons if they don't use insulin?

I heard somewhere that as opposed to other cells, neurons do not use insulin to get their sugar supply. Why is that? What is the alternative mechanism? I assume sugar can't just enter the cell ...
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660 views

Are there records of monozygotic twins in which one experiences androgen insensitivity syndrome

I have given my high school biology students the thought experiment of "What would happen if a researcher induced twinning of a female zygote and then replaced one of the X Chromosomes with a copy of ...