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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475 views

What advantage does an enzyme serve over catalysis by the addition of heat energy?

I understand that an enzyme lowers the activation energy, allowing the reaction to run faster, however I am not sure, how it may be favorable during the addition of heat energy. Wouldn't that lower ...
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1answer
64 views

How can I isolate live Wolbachia endosymbionts from Drosophila [closed]

I am interested to culture Wolbachia bacteria in cell line.
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1answer
54 views

What is a positive epitope fragment

What is a positive epitope fragment? I found one paper on the subject: COBEpro: a novel system for predicting continuous B-cell epitopes by Michael J. Sweredoski and Pierre Baldi
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1answer
775 views

What kinds of cells does human saliva contain?

I have heard that our saliva contains cells. What cell types can be found in human saliva?
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1answer
244 views

How long can a human neuron live outside the body in a controlled environment?

Have there been any experiments that have kept neurons alive (stationary), without preserving methods such as freezing? If yes, then how long were the cells kept alive for?
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1answer
180 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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1answer
259 views

Trying to differentiate between the three muscle tissues with small pictures

For an assignment I have to differentiate the three types of muscle tissues in these three pictures . I'm having difficulty seeing the striations and branches etc. because the pictures are so small. ...
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1answer
35 views

Why does a tumour's genome change depending on the environment?

According to the book "Primer of The Molecular Biology of Cancer" by Vincent, Theodore and Ateven, the tumour cell is changed depending on its environment. performed genome-wide analysis on three ...
5
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1answer
168 views

Can methylation of a promoter induce gene expression in some rare cases?

Can methylation of a promoter induce gene expression in some rare cases? I've read somewhere that methylation of an intron can induce gene expression (eg. Igf2). How is that even possible? Thank ...
9
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2answers
4k views

What are the differences between cancer and tumour?

What are the differences between cancer and tumour? I mean is it in the DNA or shape or something else... And how can a benign tumour turn into a malignant tumour? The body has a lot of tumours all ...
7
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1answer
355 views

Is this a grass cell?

I found this picture online claiming it was a grass cell. Clearly it is a cross section image but I was hoping you could tell me if this is actually grass, or something else if anything.
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3answers
422 views

why do some cells in the body prefer necrosis to apoptosis as a means of cell death?

There are many programmed cell death pathways, but some cells show a greater preference for some over the other. I'm wondering as to why if necrosis is an inflammatory response that causes damage to ...
3
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0answers
44 views

What has to duplicate before cell enters M phase? [closed]

What has to duplicate before cell enters M phase? DNA histones centrosome mitochondria (any other organelles?) condensins (not sure?) have I forgotten anything? Thank you in advance!
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3answers
316 views

How do we look inside the cell?

My sister is in 9th grade biology and her teacher avoided answering the question of how we actually study the inside of a cell. I haven't taken biology in a while but I'd like to give her an answer. ...
3
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0answers
229 views

How to prevent e coli from clumping (for FACS)?

I'm performing FACS on e coli, but the cells are clumping together so each event is multiple cells. I ran a control where I had one flask of e coli expressing GFP, and one flask expressing RFP. Run ...
7
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1answer
115 views

What were the first neural systems like?

I'm curious about the origin of the neural network. I'm thinking perhaps once life evolved beyond the single cell organism, it needed a simple neural network to coordinate those cells, and cell ...
3
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0answers
48 views

Why is ATP the main nucleoside triphosphate used to exchange energy? [duplicate]

Out of all of the nucleoside triphosphates what makes ATP the most used? Is it its structure? The amount of energy it contains? Why is GTP not used as much? What is the deal with the other nucleoside ...
7
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1answer
160 views

What is the mechanism by which lamins regulate gene expression?

The heterochromatin is generally localized at the nuclear periphery (also near nuclear lamina), whereas active genes are preferentially found in the nuclear interior. Children with Hutchinson-...
2
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1answer
59 views

How semi-synthetic cell with artificial DNA works

I know that by now this is old new but I heard that a cell that used a synthetic pair of nucleotides, called X and Y, have been made. My question was, how did the cell understand the X and Y ...
3
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2answers
107 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 ...
4
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1answer
135 views

What effects does being cryogenically frozen have on a person's body? [closed]

I'm wondering what effects are known to happen to a person's cells when a person is cryogenically frozen, especially those that need to be overcome in order to "bring them back to life." From a ...
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3answers
2k views

Does a man contain all the genes needed to make a woman?

This question is brought on by a Sci Fi novel I am thinking about writing. The plot device involves a colonist in charge of building a population on a new planet who loses his supply of embryos and so ...
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1answer
201 views

Why do some cells like myofibrils have multiple nuclei?

I see that myofibrils (muscle cells) contain not one, but multiple nuclei. Why is this so? Do all the nuclei participate in cell division?
7
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1answer
1k views

Are pulp cells (in oranges) normal plant cells?

Does a pulp cell contain all the elements that a 'normal' plant cell contains? I've searched for an hour to find more information about this but couldn't find anything useful. Is the pulp cell the ...
0
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1answer
156 views

What is the second phase of photosynthesis?

I really want to know what the second phase of photosynthesis (in the dark) is. I have a fair understanding of the first cycle where molecular oxygen is generated under the influence of light, but I ...
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1answer
1k views

When do the spindle fibers attach to the chromosome

At what phase does this occur in mitosis (or even meiosis); some text books say prophase while others say metaphase.
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2answers
228 views

What triggers programmed cell death in humans (from outside the cell)?

What triggers programmed cell death in humans? Is it decided by the brain (for the entire body)? Or is it a local decision of a cell by its environment? Something else? I realize that there might be ...
5
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1answer
149 views

Are There Exceptions to Animal Cells not Having Cell Walls?

In the January Issue of SciAm (discussing Haemophilia): When damage occurs to blood vessels, exposure of the blood to collagen in the cell walls and material released by the cells triggers the ...
5
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1answer
127 views

What is an operon?

What is an operon in a eukaryotic cell, and how does it regulate the expression of genes? I've already read Wikipedia, but it is not enough clear to me. Unfortunately my knowledge in genetics are very ...
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0answers
65 views

How organized is the inside of a cell? [closed]

I know cells have many ways of organizing and controlling what goes on inside their membranes. But just how ordered or chaotic is it inside a cell? Here's a few thoughts I had. Consider the ...
2
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2answers
61 views

Are we more/less resistant to infectious diseases during an allergic reaction?

To my understanding, an allergic response is a non-adaptive response of the immune system to some molecule. The molecule in question is therefore "thought by the immune system" to be infectious ...
2
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1answer
47 views

How are lesions in the RNA corrected?

I quite understand why thymine is present in DNA. So we can mark it out where cytosine undergoes a reaction and is converted to uracil. Then we can repair the DNA. But how can we make that out in RNA ...
8
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1answer
427 views

Single long axon vs serial neurons

Based on the comments in this post and also this chat. For discussions and speculations please comment in the chat. The basic question is what is the advantage of having a single long axon such as ...
2
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0answers
44 views

How do I get recombinant proteins into the nucleus of mammal cells?

I know that there are Nuclear Localisation Sequencenes (NLS). They can be taken from endogenous or viral proteins and fused to the N or C terminus of my recombinant protein. Which is the best one? ...
35
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2answers
2k views

Can brain cells move?

I was discussing this with my brother. I'm pretty sure I read somewhere that they can move. Thanks EDIT: By movement I mean long distance migration (preferably within the brain only).
3
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1answer
52 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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3answers
369 views

Studying effects of alcohol on cells

I am wondering about the logistics of a simple experiment with say 3 types of alcohols, and various concentrations of each, with a control(s) I would like to research the effects of alcohol on ...
3
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1answer
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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1answer
80 views

How does a multicellular, eukaryotic body treat heat-resistant pathogenic bacteria?

How does the said body treat heat-resistant pathogenic bacteria? If fever is the body's response to foreign microbial invasion, then what happens if the bacteria is heat-resistant but the body's own ...
6
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1answer
656 views

Why do some internal organs regenerate?

I have been reading about the human liver and zebra fish heart muscle having the ability to regenerate. It seems to me that these organs have very little chance to become damaged or worn out. At the ...
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1answer
2k views

How are lysosomes formed?

Lysosomes are irregularly shaped membrane bound organelles containing 50 different types of enzymes. But how are they formed? How are they produced??
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0answers
94 views

What proportion of salt in water would make it not dehydrate nor hydrate someone? [duplicate]

Drinking sea water can be deadly as it contains too much salt, basically de-hydrating the body. Normal tap water contains little salt and is good for re-hydration. My question: How much salt needs to ...
1
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1answer
534 views

Apoptosis vs necroptosis

I understand that apoptosis and necroptosis share the same upper part of the pathway, but I cannot seem to distinguish when is each one activated? From my readings, it seems that when procaspases 8 or ...
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2answers
2k views

Book Recommendations: GRE Subject Test In Biochemistry, Cell And Molecular Biology

There are probably a lot of really good answers that may vary significantly in terms of content. I'm looking for a set of books that I can read in preparation for the GRE Subject Test In Biochemistry,...
2
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1answer
63 views

What are the features on a microscope one needs in order to do lab work?

By lab work I mean urinalysis, blood work(live as well), fecals, cytologies, histologies and all other. I have read(partly) a book(from 2002) on lab diagnostics and the author did not mention ...
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0answers
26 views

Slicing cell cultures frozen in vitrified ice with a laser for CryoEM

Could a cell culture frozen in vitrified ice for CryoEM be effectively sliced into thin planes and resolved images produced? I was thinking if this could be done to get images from inside a cell.
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1answer
34 views

Centriole genes Knock-out Experiment in Common experimental animals?

Anyone know of any experiments that have knocked out the genes for producing centrioles in a worm, mouse, fish, fly or whatever animal? Are the genes for centrioles even identified? It has been shown ...
3
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2answers
267 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 ...