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 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. ...
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557 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 ...
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0answers
30 views

Can I leave BL21(DE3) cells in room temperature?

I am preparing competent cells, and I finished inoculating a single colony in SOB. It has been incubating at 37 degrees Celsius for almost 16 hours since, and it's getting very late where I live. I ...
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20 views

Why do flagella form a bundle only when they rotate counterclockwise during chemotaxis?

During Chemotaxis in bacteria with flagella, the flagellar rotation dictates how the cell moves. If the flagella rotate counterclockwise, then they form a bundle at one end of the cell (---O) and ...
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23 views

Procedure for doing western blot [closed]

I am writing a step by step guide for doing a western blot for a class. It is intended for any one with basic Biology lab skills. I am hoping people will review my draft and give feedback on how to ...
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0answers
33 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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96 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 ...
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0answers
42 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 ...
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78 views

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

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 ...
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38 views

How many cells are there in the apical meristematic tissue?

How many cells are there in the apical meristematic tissue? Looking at this picture... , I would tend to think that there are few hundreds cells in the meristem tissue. But I guess this is a ...
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41 views

What does the term 'epitope mapping' mean? [closed]

Epitope mapping means identifying the binding site of antibodies on the target antigen. This means that the site to be identified is part of the antigen and not antibody, am I right?
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234 views

Can someone explain the color-changing unit (CCU) to me?

I've been physically carrying out serial tenfold dilutions on samples of Ureaplasma to work out the color-changing units (CCU). As a definition, the CCU is the highest dilution at which there is a ...
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30 views

A program for cell motility assessment with a batch process function?

Cell motility assessment is a branch of experimental biology or medical science. One example could be an assessment of treatment effects on sperm motility of an animal. The standard procedure involves ...
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0answers
74 views

Microscopy Book Suggestions

I've learned programming through great book recommendations, many from the Stack Exchange series of sites. I'm hoping to take this approach to gaining a fundamental understanding of how fluorescence ...
3
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1answer
69 views

What are senescent cells doing in our bodies? [closed]

I'm reading a paper that mentioned the elimination of senescent cells delays aging. I'd like to receive more information about it. The Baker study published in Nature demonstrates that targeted ...
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3answers
5k views

DNA is charged negative. Where is all the positive charge in my body?

DNA is charged negative because of its phosphate backbone. Since charges need to be balanced (so that there are no charges building up somewhere), what is the positive charge which neutralizes this ...
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4answers
102 views

Why is too much glucose harmful?

I learned the citric acid cycle in biotechnology school and how cells work; about ADP and ATP and how the Cellular respiration (C6H12O6 + 6O2 -> 6CO2+6H2O) works. I am interested in understanding why ...
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174 views

A question on glycolysis

In the first step of glycolysis, the glucose ring is phosphorylated. Phosphorylation is the process of adding a phosphate group to a molecule derived from ATP. As a result, at this point in ...
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72 views

peptide MHC microarray

"The recent technology is peptide–MHC microarray or artificial antigen-presenting chip. In this technique, recombinant peptide–MHC complexes and co-stimulatory molecules are immobilized on a ...
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3answers
163 views

Why doesn't the cytosol dissolve the polar structures?

we know that cytoplasm of cells are filled with water molecules and other hydrophilic molecules so my question is why the water of cytosol doesn't dissolve the ionic part of the lipid bilayer or why ...
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3answers
109 views

What do cells do when they aren't creating proteins?

I've always thought that the majority of the "work" in a cell is protein production, until I read the following. The Wikipedia article on the central dogma of molecular biology states this: 80% ...
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4answers
58 views

Do I need to serially dilute E. coli cultures for optical density measures?

I am expected to track cell growth by measuring the incubating culture's cell concentration every 30 minutes or so. So my questions are: Why do I need to do serial dilution (assuming that I do)? Why ...
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2answers
229 views

Can cell exist without Ribosomes? [closed]

Last night I came across a question that goes as follows:- Cells cannot exist without a) cell wall b) cell membrane c) mitochondria d) ribosomes I am getting confused with option B and option D ...
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2answers
104 views

Regarding cancer cells and telomeres

If cancer cells have telomeres are they different than the telomeres in non-cancerous cells? Would cancer cell telomeres be somehow 'set-up' to function almost indefinitely; in other words are 'they' ...
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1answer
152 views

Why are hard boiled eggs so homogeneous?

A eukaryotic animal cell is a complicated piece of biological machinery. Some major structures inside of the cell (see the image below) include: the nucleus, mitochondria, Golgi vesicles, and various ...
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1answer
621 views

Why are red blood cells considered to be cells?

Wikipedia states that a cell is the basic structural, functional and biological unit of all known living organisms. Cells are the smallest unit of life that can replicate independently. It then ...
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1answer
422 views

How exactly does marijuana damage brain cells?

I've heard that THC can cause permanent damage to brain cells. I've also heard this reffered to anti drug propaganda. Another theory i've read is that temporary effects reduce intelligence but long ...
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1answer
142 views

Where does an organism store reserves of amino acids?

Where does an organism store reserves of the amino acids it needs to build various proteins it needs -- in the liver ? in the blood ? in every cell ? Thanks
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53 views

What are multicell spheroids?

I'm from a maths background and I'm doing some research on mathematical models of cancer. I've come across alot of literature mentioning "multicell spheroids" in the context of avascular tumours. I ...
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2answers
47 views

Localization of Protein Kinase-A

Is protein kinase-A located in the cytosol/cytoplasm of cells or in the plasma membrane? Also, is it considered a receptor molecule since it is dependent on cAMP? Any and all help is appreciated. ...
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1answer
57 views

Trimming of tRNA precursors

From Molecular Biology of the Cell (4th edition) by Bruce Alberts et al. (Chp 6, Pg 338) : Both bacterial and eucaryotic tRNAs are typically synthesized as larger precursor tRNAs, and these are ...
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1answer
886 views

How do nutrients get to the cells they need to get to?

I understand the basics of digestion. I know that nutrients get absorbed by the microvilli, enter the bloodstream and travel to the liver but after all that, what is the biological mechanism that ...
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1answer
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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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
91 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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510 views

Beginning with centrifuge experiment

This is the first time I do a centrifuge experiment with my own centrifuge machine, it's just simple made by a rotor that can rotate the tube at high speed. As I know a centrifuge machine can be using ...
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2answers
173 views

Up to date B cell review

Where would I find an up to date (last 6-7 years max) review on B cells? I've tried searching through pubmed with filters, cochrane library, medline and various other resources including searching old ...
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1answer
59 views

Measuring the density of surface antigens

I'm trying to get a sense of the variety of methods used for determining the number of cell surface antigens and receptors. This is notably different from determining the affinity of these surface ...
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2answers
53 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 ...
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1answer
311 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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2answers
74 views

Does the cellular response to every receptor work the same way?

I heard somewhere that activating any receptor results in the same intracellular response (signaling) which involves NF-κB. If that is true, I hardly understand how the cells distinguish between ...
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1answer
26 views

epitope prediction/ mapping

B-CELL EPITOPE PREDICTION Regarding this article: "Such a molecule can be synthesized or, in case of a protein, its gene can be cloned into an expression vector."----- is a particular line in ...
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1answer
70 views

Can (any) human cells learn?

I'm not talking about single celled organisms, but actual cells in your body. Is there any evidence that they can learn to, say, navigate an environment or avoid an aversive stimulus like an animal ...
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1answer
66 views

How to study the effect on tau protein isoforms on microtubule based transport?

From what I read, A-beta plaques inhibit microtubule based transport of mitochondria when tau protein is present in the cell. How would I be able to do a test to see if one isoform of tau is more ...
2
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1answer
668 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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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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2answers
61 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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2answers
306 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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2answers
134 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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1answer
71 views

Domains in cell membrane

How is movement of proteins and lipids between different domains of cell membrane prevented? Why is the noncytosolic layer not able to do lateral movements between domains but cytosolic layer is able ...