Known also as "cytology" is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death.
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121 views
Does pheomelanin have a useful biological function?
Melanin is a natural pigment that is categorized into two main forms, eumelanin and pheomelanin. It's well documented in the science literature that increased eumelanin levels reduces the risk of ...
4
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2answers
258 views
Advice on Cell Biology texts by Alberts
I am currently reading "The Chemistry of Life" by Rose. It's a great book (to me as a lay reader at least) and an interesting topic so I am interested in pursuing some of the further reading he ...
5
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1answer
107 views
Using ion-exchange chromatography to purify DNA from a cell extract - Is DNA more negatively charged then RNA?
When applying this method we have a glass or plastic column of resin which is positively charged. Then we pour cell extract into the column in order to capture the negatively charged particles which ...
4
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2answers
486 views
Why does alcohol cause the hemolysis of RBC in a large proportion?
I had today an experiment that we put 95% alcohol to the blood which made it completely transparent so hemolysis must have occurred.
I started to think about the reasons.
I think that this is because ...
3
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1answer
113 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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2answers
491 views
Why can't a human regenerate limbs like some other species?
When a person's arm is amputated, the arm will no longer be able to grow back. However, in salamanders, the arm actually grows back.
In comparison to a human, what is really happening to the cells ...
5
votes
1answer
68 views
Number of spindle fibres during Metaphase?
During metaphase, the chromosomes are arranged on the equatorial plate and are attached to spindle fibres. After S phase, can the cell be said to attain the configuration of 4n?
Also, during ...
2
votes
1answer
39 views
What is the title of Darwin's paper on cellular structure?
I read somewhere that Darwin wrote a paper that dealt with cellular structure, but I've been unable to find the title or contents of the paper because Darwin wrote such a volume of material. What is ...
3
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0answers
28 views
Patch-Clamping Neurons Resources
Are there any lectures available on Patch-Clamping?
Were can I find a mathematical model of Patch-Clamp? (that can be easily implemented in matlab).
I have found some step-by-step protocols on ...
2
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1answer
37 views
Similarities Between Cells?
Which of the following are usually identical between a lung cell and a brain cell, from the same person, assuming that they are normal (non-cancerous) cells? Circle your choice(s).
...
5
votes
1answer
270 views
Multi-nucleated cells: advantages and examples?
This question arises because I saw that monocytes and leukocytes are commonly called 'mononuclear cells' in the scientific literature. The implication of course being that other immune sub-types are ...
6
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2answers
128 views
How do cells “know” what “type” to differentiate into?
I have been reading about Townes and Holtfreter's work in 1955, in which cells are dissociated from a blastocyst in an alkaline solution then mixed together and spontaneously reaggregates based on ...
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2answers
78 views
How are different types of cells created from zygote?
In the process of mitosis that starts from zygote, how do different cells appear? What happens that some cells become one type and some another?
For example, is there a cell that divides into a ...
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1answer
84 views
Is there sufficient evidence that human cells are not intelligent? [closed]
Being structurally composed of one or more cells, which are the basic units of life.
Yet within a cell, there seems to be the same behaviors that define life:
Regulation of the internal environment ...
5
votes
2answers
93 views
Creating a cell, not from another cell. Will it be possible?
If some time in the future, we can know exactly what a cell (for example simple prokaryote bacteria) contains, (I mean, exactly which molecules, the shape of them, the density of each, everything), ...
6
votes
1answer
161 views
Does DNA contain information beyond protein synthesis?
It's well known that genetic information is stored in DNA. As far as I know, DNA only has information at the protein level. What about higher levels, such as organelles, cells, tissue, organs? Is ...
3
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2answers
97 views
Why is most tissue cellular?
Most tissue is comprised of cells. Why? It would seem inefficient to have so many individual nucleus, membranes, etc.?
Specifically: Not all tissue is cellular. Much tissue is extracellular matrix. ...
6
votes
1answer
185 views
Methods of nuclear transfection - nuclear transport
I am reading through the ENCODE papers, which is taking me well out of my comfort zone in terms of modern laboratory techniques. At the risk of asking a question which may well be thoroughly answered ...
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1answer
395 views
Is there an advantage to linear chromosomes?
The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
3
votes
2answers
79 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 ...
2
votes
1answer
216 views
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 ...
5
votes
1answer
3k views
How many human cells are there in our body, on average?
How many human cells are there in our body, on average?
Wikipedia says 1013:
Bacterial cells are much smaller than human cells, and there are at least ten times as many bacteria as human cells in ...
4
votes
2answers
170 views
Under what circumstances will a human neuron divide?
I read somewhere that a mature neuron loses its ability to divide, except for very specific situations. I was unable to find the description of those situations. What are they?
(I'm sorry I'm not ...
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3answers
319 views
Are there verbs for “undergo mitosis” and “undergo meiosis”?
From my experience on SE sites, I believe this is the right site to ask this question under "terminology".
I've been trying to find out whether English has one-word verbs for "undergo mitosis" and ...
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vote
0answers
50 views
When should endocytosis inhibitors be used in cell binding assays?
I'm beginning to do some cell-binding assays and I would like for my proteins to not be endocytosed by my mammalian cells. Typical suggestions are for the cells to be kept on ice and that the binding ...
6
votes
1answer
226 views
Does every mitochondrion in a cell contain the same DNA?
I know that mitochondria of eukaryotes have their own DNA, more similar to that of bacteria than to the rest of the cell's DNA. I also know that a cell can have plenty of mitochondria, and I ...
6
votes
3answers
100 views
What gaseous substances do humans emit?
Other than CO2 and Methane what other gases do humans produce or emit?
For example, does skin decomposition, or aerobic respiration emit any special gases that people don't normally realize or know ...
7
votes
1answer
135 views
Why aren't mitochondria and plastids considered symbiotes of eukaryotic cells?
Mitochondria and plastids have their own DNA, their own membranes, and their reproduction is not tied to the reproductive cycle of the host cell. However, they are considered to be organelles rather ...
6
votes
1answer
68 views
How much energy does a cell expend maintaining its contents?
In software engineering, an analogy is sometimes made using biological cells. I would like to know whether it has basis in fact.
People say (Alan Kay was first) that "objects" in software should be ...
5
votes
1answer
59 views
Free-flowing cells and those that are stuck together?
I've been thinking about the development of an embryo from the zygote stage.
How is it that when cytokinesis takes place at that stage, the cells all stick together in a little ball, but later in ...
6
votes
1answer
103 views
How are synaptic vesicles brought to the synapse?
I'm reading about how synaptobrevin is used to identify synaptic vesicles for tethering near the synaptic cleft. Since neurons have a synapse and dendrites, I'd like to know how exactly the vesicles ...
23
votes
1answer
366 views
What is itching?
What exactly at the molecular level is itching? What physiological function does itching serve, if any? I cant remember the reference but a PLCb3 null mice lost the itch phenotype, so presumably it is ...
6
votes
1answer
88 views
Macromolecule levels in daughter cells after fission
When a prokaryote undergoes binary fission, how are the non-DNA macromolecules distributed between the two daughter cells? This is motivated by comments on a previous question and a G+ discussion. I ...
5
votes
1answer
78 views
Cell proliferation limit and senescence of embryonic stem cells and fibroblasts
I am trying to understand the importance of proliferation limits and cell senescence. In particular, I would like to compare the proliferation limit of Embryonic Stem cells (ES) and fibroblasts (which ...
5
votes
1answer
146 views
Computational/mathematical models for predicting phenotype from genotype
Karr, Sanghvi, et al. (2012) propose a whole-cell computational model for predicting phenotype from genotype in Mycoplasma genitalium. Their model simulates myriad cell processes such as DNA ...
4
votes
1answer
172 views
Lifespan of connective tissue cells
This post is regarding a follow up on my initial post on "Properties and life cycle of chondrocytes and tenocytes".
I am elaborating on my question on the lifespan of tenocytes and chondrocytes.
...
4
votes
1answer
55 views
Intrinsic apoptosis in erythrocytes
With a lack of mitochondria, can red blood cells perform intrinsic apoptosis and do they have another way of generating cytochrome c to attach to a CARD domain and assemble the apoptosome?
Or are ...
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0answers
52 views
Properties and life cycle of chondrocytes and tenocytes
Questions regarding chondrocytes and tenocytes:
Do these cells replicate, or are they regenerated from mature stem cells?
How often are these cells regenerated?
How long do they live?
Do they ...
2
votes
1answer
174 views
Is collagen supplementation useless?
When collagen is digested is it broken up into usable components that the body can use to produce its own collagen?
What evidence is there that supplementing with collagen type I & II etc.. can ...
4
votes
2answers
2k views
How do archaea relate to eukaryotes and bacteria?
I've read that they all share some genes, internal structure, and behaviour with each other, but with different degrees of overlap depending of what the function is. E.g., archaea have some eukaryotic ...
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vote
1answer
28 views
Where can I find a transcriptome of a normal uveal melanocyte?
I am looking for a database where I could find a transcriptome (say obtained with a microarray analysis) of one (or ideally many) normal uveal melanocytes ?
5
votes
1answer
53 views
Significance of basal lamina for outer layers of epithelium
In stratified (not pseudostratified) epithelia such as the epidermis, what purpose does the basal lamina serve for the outer layer cells which do not even stand in contact with it?
Also, how do these ...
7
votes
1answer
136 views
How fast do different organs turn over cells?
It is said that the human body turns over all cells or molecules in 7 year cycles. This is not quite correct, because there are different organs changing at different speeds. My interest is what is ...
4
votes
1answer
67 views
Regarding TIMP and MMP enzymes
Are there substances that can promote TIMP enzyme production, or MMP enzyme production or supression in tendons?
Are there medical tests that measure quantities of MMP and TIMP enzymes in tendons?
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votes
0answers
52 views
Can NSAIDs impact negatively the healing of tendons?
There are a number of articles regarding NSAIDs having a negative effect on healing conditions like tendonosis and tendinitis. From what I understand the channel through which they reduce inflammation ...
4
votes
1answer
234 views
Is there a relationship between efficiency of cellular metabolism and warm-blooded-ness?
My BIO 101 book states that when human cells convert glucose to ATP, the process is only approx 35% efficient, and much of the potential energy is lost as heat. However, that heat is useful to us in ...
5
votes
1answer
74 views
Which cells are responsible for the extracellular matrix remodeling?
I am studying a case of tendinopathies induced by an alteration of how the extracellular matrix is being remodeled.
From my understanding there has to be a careful balance of MMP (metallproteinases) ...
5
votes
1answer
144 views
Are the cytosol and extracellular fluids electrically neutral?
I've found several sources that state that overall, the cytosol of a cell is electrically neutral. The extracellular fluid is also purportedly electrically neutral. How can that be when we have ...
3
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0answers
19 views
What metabolically happens when an egg fuses with the nucleus of a somatic cell
In stem cell biology, it is recognized that embryonic stem cells are transcriptionally inactive for the first 3 days of development. However, during somatic cell nuclear transfer, the nucleus is ...
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2answers
55 views
Macrophage pathogen fixation
Overly simplified, macrophages recognise pathogenic patterns and endocytose anything that matches them.
That also works on bacteria, which are quite often very mobile. What if a bacterium was just ...
