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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Book-recommendation: Biochemistry

I need to have a book which covers following topics two may also be fine: (a) Structure and role of carbohydrates, fats, fatty acids and cholesterol, proteins and amino-acids, nucleic acids. ...
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139 views

Problems understanding membrane potential

I understand that membrane potential is the difference of the extracellular and intracellular ionic charges, due to their concentrations. We say that the extracellular space has a charge of 0 and then ...
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2answers
55 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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What do we know about the cellular structure, processes, environment, and immediate ancestors of the last universal common ancestor (LUCA)? [closed]

I am up for all scientifically sound speculations, and sources are highly welcome. I've looked into this quite a bit myself via scholar.google, the wiki article, and /r/askscience. I'm really looking ...
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182 views

Active & passive transport question

If an element, ion or molecule is found in a cell is it possible to tell which method of transport was used? for example if a hydrogen or sodium ion was found in the cell could you tell if it got ...
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511 views

Are there any multicellular forms of life which exist without consuming other forms of life in some manner?

The title is the question. If additional specificity is needed I will add clarification here. Are there any multicellular forms of life which exist without requiring the consumption (destruction) of ...
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78 views

If DNA is the input, what is the output? [closed]

How does cells use the DNA inside them? I am looking on DNA as a strip of tape of Turing machine, but with machines its easy. I can read the tape and calculate the behavior of that machine. With cells ...
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40 views

Fruit colour related to the dissolving of pectin

What does the dissolving of pectin have to do with the colour of a fruit?
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338 views

What's the difference between growing cells in culture and cloning them?

The wikipedia page on Hela cells refers to George Gey being able "to isolate one specific cell, multiply it, and start a cell line." Later it says, "In 1955 HeLa cells were the first human cells ...
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76 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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219 views

How does an embryo know where to grow limbs etc

For example you have a cell or already a bunch of cells. Those cell(s) divide and after several week you have a grown organism, for example a human with limbs, several different organs etc. However, ...
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21 views

Mechanisms of Flagella

I know that dynein arms and microtubules are involved in the contraction of certain parts of the flagella to produce a wave motion, but I don't understand they are related to the 9+2 structure of the ...
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3answers
182 views

Stardust or the elements in our bodies

How do we know we are made of stardust? As our cells divide, are our atoms repurposed from existing materials or spontaneously generated? Do we consume materials after we are born that contain ...
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60 views

Bacterial Cell Problem

A microbiologist has discovered what she thinks are two new types of algae. The first cell (Organism 1) appears cubic and is approximately 1.5 μm long, 1.5 μm wide and 1.5 μm deep. The second ...
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54 views

Is carbohydrate an important part of phospholipid?

My professor tells us that carbohydrate is an important part of phospholipid, but phospholipid is composed of Choline, Phosphate, Glycerol and two Fattyacid, and I don't think even one of them is ...
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61 views

About excessive cellular growth

When there is 'excessive' cell growth 'ordered' by the human body in some specific part of the body that is not part of the usual repairing mechanisms, does this cause extra telomere 'shortening' or ...
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2answers
105 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' ...
2
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1answer
158 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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59 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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136 views

Mechanism of Muscle Growth

According to this video (sorry for the poor reference but it represents my level of understanding in physiology), muscle grow as a consequence of repairing micro-lesions. How are these micro-lesions ...
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1answer
103 views

Can Mono-Cell or other organism self-replicate?

I have a question regarding how organism replicate them self to create an other organism, We know that in animal reign, we need a male and female that will generate a new being. what I want to know ...
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84 views

Where do the electrons and protons formed from biological reactions go?

In a reaction like disulphide bond formation protons and electrons are released. These particles are presumably damaging in high levels. What systems are in place to prevent a build up of electrons ...
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1answer
45 views

Determining and Differentiating specific ATPases

In respects to this certain ATPase transporter. What do i look for in respects to determining what specific kind it is out of: F-ATPases V-ATPases A-ATPases P-ATPases E-ATPases Im assuming that ...
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1answer
46 views

Immunomic Microarray

"One can measure two or more signals simultaneously determined by a single feature, i.e., epitope in immunomic microarray DNA microarrays measure one response value for each gene per sample; that ...
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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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recombinant peptide MHC complex [closed]

What is recombinant peptide-MHC complex??? Recombinant DNA means "to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological ...
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2answers
124 views

Transmembrane Protein Problem

Problem A transmembrane protein has 1000 aa. The 5th aa is found on the external side of the cell membrane. It interacts with the aqueous environment outside the cell. Amino acid 90 is inside the ...
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3answers
2k views

How fast do cancer cells divide, compared to normal cells?

This question suggests that we have, on average, 50-70 billion cell divisions per day. I just read that cancer cells divide more often and are therefore more prone to radiation. I am wondering, for ...
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Where do lost membrane proteins go after exocytosis?

Exocytotic vesicles take away membrane proteins and glycocalyx on the cell's plasma membrane surface. When those vesicles are released into the interstitial fluid and wherever else, where do they go? ...
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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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Regarding cellular self-destruction

I heard and read telomere 'health' or 'length' ( if that's right ) has alot to do with cell 'health'. If telomere 'abilities' are 'restored' to a 'healthier' status then the cell it is in functions as ...
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732 views

Why doesn't the cell membrane just… break apart?

Forgive me if this is a silly question. I can't understand the basics. Why doesn't the membrane just... break apart? What's keeping the layers in the phopholipid bilayer together? I know that the ...
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1answer
67 views

What is hTAP?? Please help [closed]

Could not find a single article regarding this. What is hTAP? Tap is Transfer associated protein, that I know, but what is hTAP??(I have not studied biology since last 8 years and now I am going ...
2
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1answer
345 views

Difference between sequential and conformational epitope

Is the difference only in its structure? Like conformational epitope has 3D structure while sequential has a linear structure?(I have not studied biology since last 8 years and now I am going through ...
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2answers
371 views

What is MHC haplotype?

What is MHC haplotype? I did check out the wiki article, but did not understand. (I have not studied biology since last 8 years and now I am going through it because I need it for my research. So if ...
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64 views

MHC restricted peptide

What is an MHC restricted peptide? I got this definition from wikipaedia, but cannot exactly extract what the phrase MHC restricted peptide means. MHC-restricted antigen recognition, or MHC ...
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622 views

Does “Garbage Enzyme cleaner” contain cleaning enzymes?

There are many recipes which call for using fruit peel fermentation process to make a concentrated enzyme cleaner solution, some variations call to add bakers yeast. So the question arises that does ...
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2answers
38 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, ...
4
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2answers
59 views

Are there known downsides to removing UV mutation hotspots to prevent some skin cancers (Genetic sunblock)?

Khavari et al. recently demonstrated that a significant fraction of one of the major forms of skin cancer (cutaneous squamous cell carcinomas) are associated with a mutated KNSTRN gene (a protein ...
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111 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... ...
3
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1answer
65 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 ...
2
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1answer
67 views

How does core-conductor model correspond to an actual neuron?

Hi guys, looking at your average neuron, it is very difficult for me to imagine how this could be translated into a core-conductor model On the neuron above, where would be the intracellular ...
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1answer
969 views

Complementarity Determining Regions (CDR)

Complementarity determining regions (CDRs) are part of the variable chains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules ...
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1answer
34 views

Degenerate Alignment Analysis

Can someone please tell me what is Degenerate alignment analysis? Could not find a good article on the internet that could help me understand what it means? (I have not studied biology since last 8 ...
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0answers
31 views

TAA- Tumor associated antigen [duplicate]

An approach to find Tumor associated antigens is based on transfection of expression library made from cDNA into cells expressing desired MHC haplotypes. Can someone please explain what this line ...
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1answer
24 views

Microarray probe and target

In a microarray, which one is called a target and which one is the probe? the one that is added later , is that the probe or the one present in the slots of the microarray, that is the probe? (I have ...
2
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1answer
41 views

What roles do cyclooxygenase, lipoxygenase, and epoxygenase have in signal transduction? [closed]

Besides oxidizing fatty acids to form prostglandins, leukotrienes, and epoxides, what other roles do cyclooxygenase, lipoxygenase, and epoxygenase have in signal transduction?
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How is it that ionic diffusion is independent of other ions?

This question arises from the explanation of what the resting potential of a cell membrane is. In the Goldman formula, there is no interaction between different ion types. If diffusion is caused by ...
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1answer
116 views

Are retroviruses cytotoxic?

There are typically hundreds of retroviruses found in healthy human beings. Are retroviruses then cytotoxic? (In other words, are they able to kill or damage other cells).
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1answer
67 views

How to measure the total number of cells in an average human body?

I have got one assignment to calculate the approximate sum total of all cells in the human body. How to tackle this problem? I know that the current statistics is $10^{13}$ cells. I wanted some hints. ...