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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why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
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119 views

Improving transformation efficiencies- induce supercoiling?

From my limited knowledge of science, I know transformation can be one of the hardest step in cloning, and that a large amount of research/trial and error has been done to improve on this step. I've ...
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53 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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1answer
87 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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2answers
91 views

How extensive is CD47?

CD47 aka the "don't eat me" signal has recently been claimed to be expressed on all tumor cells. This doesn't seem to corroborate with other cell-biology experiments. On what other cells is CD47 ...
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28 views

specific membrane conductivity of HEK293 [closed]

does anybody know the specific membrane conductivity of HEK293 cells? Does anybody know a valid source?
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211 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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107 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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1answer
58 views

Is forced cell growth related to apoptosis?

Could an instance of forced cellular growth cause some cells to have their self-destruct mechanisms to malfunction or 'turn off'thus preventing apoptosis?
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100 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
55 views

Missing cells from immunopanning

Why do I not have any cells left in my positive panning plate after transferring from the negative panning plate during immunopanning? I am trying to purify retinal ganglion cells from postnatal rats ...
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1answer
54 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
37 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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What is the distinction between chemokines, cytokines, interferons and interleukins?

They all seem to describe molecules of similar function and many people seem to use them interchangeably. Also please include any other similar molecules if I've forgotten any in the list above.
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179 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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2answers
439 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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1answer
115 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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3answers
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Do animal cells have vacuoles?

I overheard a rather heated argument about whether or not animal cells have vacuoles. One person said that they do, but they're much smaller than vacuoles in plant cells. The other person said they ...
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1answer
55 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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1answer
807 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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415 views

Does electricity cause damage on a cellular level?

As I understand it the mechanism of death when a mammal is electrocuted is that the current disrupts the SAN/AVN in the heart causing it to fibrilate or arrest. That's on a macro scale, however. ...
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1answer
95 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
64 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
197 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
69 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
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318 views

How is the mRNA transported out of the endoplasmic reticulum?

In eukaryotes the nuclear envelope is continuous with the ER, so what helps it out of that?
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1answer
55 views

Are there any enzymes in cytoplasm to help the newly-synthesized polypeptide to form tertiary structure?

Polypeptides made by ribosomes which attach to rER will go into the rER to form the tertiary structure. Those polypeptides made by free ribosomes usually stay in cytoplasm. So are there any enzymes in ...
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1answer
65 views

Attaching suspension cells to coverslip duing mycoplasma contamination detection

I am planing to screen my cell cultures for mycoplasma contamination using the Hoechst 33258 DNA staining method. This method is suitable for adherent cultures. Is this method suitable for ...
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1answer
41 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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148 views

How does skin healing work?

I stacked my bike and split my head right open. About three weeks later the scab falls off and the skin is sealed over, like magic! How does it all work? How does the brain know that part of the ...
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1answer
353 views

Is cell membrane living

We say cell wall is dead but nobody says cell membrane is dead. Is cell membrane living or dead ? If it is not dead then why is it not included in protoplasm : Protoplasm is the living contents ...
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2answers
552 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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83 views

Learning first-year biology + anatomy via documentary? [closed]

Probably going to take first-year biology in ~4 months; so was thinking to go through MIT's 7.00x on EdX… However seeing at how popular this topic is, I was thinking there might be a fun documentary ...
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1answer
75 views

Do mitochondrial DNA have repair enzymes?

Mitochondria are considered endosymbionts originated from a prokaryote. So, do they have a DNA repair mechanism ?
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42 views

Ideal blood cell

I had been given an assignment to draw an ideal blood cell, a cell which can perform the functions of almost all the blood cells (like red blood cells, neutrophils, basophils, eosinophils and ...
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1answer
667 views

Can you consider a human as alive, or is it the cells on the body that are alive?

Sorry if this question seems strange, but in the recent time I have been interested in the question of what life is and how you can define life. My question: How long can individual cells live on a ...
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How is saltatory conduction faster than conduction of unmyelinated fibers? [duplicate]

It's always the same explanation that currents are able to "hop" along Ranvier nodes instead of passing continuously along the axon making saltatory conduction more efficient than continuous ...
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2answers
61 views

Termination of translation

What dissociates first - the last tRNA, mRNA and release factors or the subunits of ribosomes? I tried searching this from Lehninger but couldn't get a clean answer.
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1answer
135 views

Number of genes required to sustain life

Are there estimates of the minimum number of genes required to sustain life? In what I mean by life here, I don't include viruses.
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2answers
501 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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0answers
36 views

Fusion of neuron with a S phase cell

There was some experiment in which a S phase cell was fused with other cell and the other cell also began to replicate DNA. Would the same happen if fused with nerve cell ? Why or why not?
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Critical pO2 threshold for cell division?

I'm a physicist asking questions on an aspect of cellular metabolism, so excuse my biological ignorance! Hypoxia is a frequent complication of certain tumour types, and has quite an implication for ...
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36 views

Why must abortive transcription repeat itself a number of times?

Why must abortive transcription repeat itself a number of times before a stable DNA:RNA hybrid containing a transcript of 11 ribonucleotides is formed?
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2answers
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Why is saltatory conduction faster than continuous conduction?

How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental ...
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2answers
108 views

How is it that the WI-38 cell line isolated by Hayflick in 1962 is still very much around and not affected by the 'Hayflick Limit'?

I have searched the net and I have not been able to come up with an clear answer. Edit: Here is the para quoted from Nature http://www.nature.com/news/medical-research-cell-division-1.13273 "So began ...
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1answer
187 views

What is 'calcium conductance'?

What is the meaning of calcium conductance in ion channels. I encountered this in the following text: It was established that the µ and δ opioid receptors open potassium channels, which results ...
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2answers
92 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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2answers
587 views

Are mature RBCs prokaryotic?

Mature mammalian RBCs have all the characteristics of a eukaryotic cell except that they don't have a nucleus, they don't have any cell organelles. Does this mean that RBCs are classified as ...
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2answers
83 views

Why can't cell division happen the other way around?

Mitosis in eukaryotes happen in this order: DNA replicates and then the cell divides. Why doesn't it happen in reverse order (i.e., cell divides and then replicates the DNA)? I am talking about ...
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2answers
2k views

How do plant cell divide without centrioles?

Most plants do not have centrioles , so who does their function ?