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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9
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2answers
150 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 ...
1
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1answer
29 views

How many NOD like receptors in Human?

This is pretty specific question maybe. Anybody have an estimate? For Toll Like Receptors there are something like 10... http://www.jbc.org/content/276/4/2551.long I'm only finding NOD1 and NOD2 => ...
2
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2answers
78 views

Recommend good conversational books to learn about cell and developmental biology or biochemisty?

I'm an engineer by training and teaching myself the basics of cell and developmental biology. I'm using Scott F. Gilbert's Developmental Biology and Alberts' Essential Cell Biology right now, and they ...
4
votes
1answer
31 views

Why MHC class I antigen presentation exist in normal cells?

The book "Kuby Immunology" states that normal infected cells might present antigenic peptides on their surface via MHC class I, but these can't activate naive CD8 cells. Only infected professional ...
4
votes
1answer
55 views

Are stem cell lines cryogenically preserved or commercially available like HeLa cells are?

There are HeLa cells, which were taken from sick cancer patient and now is growing worldwide in different laboratories for experiments. HeLa cells can be kept because they are immortal and so they are ...
1
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0answers
25 views

What is a “NuMA protein”?

I just got out of a lecture on mitosis and this part was incredibly confusing. After searching my textbook it doesn't cover it that well either. The professor mentioned a NUMA protein that is ...
5
votes
1answer
102 views

During the process of correcting mutations via gene therapy, is the defective gene removed?

Just recently started learning about gene therapy, many websites explain that the corrected DNA can be added to the genome using a vector and all that. I just don't understand what happens to the ...
8
votes
1answer
136 views

What specific membrane adaptations do cells have for saline-rich environs?

Are the cells of marine animals and flora equipped with special ion exchange pumps to mitigate the effects of a saline-rich environment? Or have the cell's membranes adapted through structural ...
0
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1answer
36 views

GPCRs: Gi and Gs

GPCR = G-protein coupled receptor Gi = G inhibitory alpha subunit Gs = G stimulatory alpha subunit Are there structural differences between Gi and Gs subunits (secondary structure)? Or is it just ...
4
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2answers
128 views

Are there human cells, apart from red blood cells and platelets, without a nucleus?

I know that blood platelets and erythrocytes do not have a nucleus. Are there more cells in the human body without a nucleus, such as pancreas, cartilage, or lung cells?
3
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0answers
22 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 ...
5
votes
1answer
51 views

Do non-enzyme catalysed reaction pathways exist?

Can their be a kind of chemical reaction pathway in a cell, that is catalyzed or regulated but NOT necessarily by enzymes? I could not find anything on Google. I have almost no background in biology, ...
3
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0answers
41 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 ...
3
votes
1answer
35 views

Microalgae without cell walls?

Most microalgae have rigid cell walls. Dunaliella Salina is a pretty famous example of an algae with no cell wall, but just a plasma membrane. Are there any other microalgae without a cell wall?. I ...
2
votes
1answer
28 views

Is there any alternative to cryopreserve cell lines without -80 freezer?

My university's -80 freezer just broke down and the repair will take 4 months according to the vendor. Is there any other way to preserve cells? Maintaining lot of flasks until the freezer is repaired ...
4
votes
3answers
15k views

What type of cell do you start with in Meiosis?

Okay, I was learning about mitosis and meiosis in school and had a question. I know in Mitosis you first start off with a Diploid (2N) cell and then end up with two ...
8
votes
1answer
96 views

What is the difference between organelle membranes?

Cells and organelles are contained in lipid bilayers. I'm particularly interested in eukaryotic organelle bilayers and the biophysicochemical differences between them. Many papers assume a ...
0
votes
1answer
123 views

What is 'refractile' cell morphology?

I can't find a definition for 'refractile' (not 'refractory', and not explicitly in an optical context). As in: A tumour cell phenotype features increased proliferation, anchorage- and growth ...
7
votes
4answers
220 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, ...
1
vote
0answers
22 views

Question about cytoskeleton coordination

I am trying to study for a biology and I am having some confusion over the following topic. Can anyone help explain/ shed some light on the concepts of Rho family GTPases. Is it true that we have Rho ...
1
vote
1answer
51 views

Why use creatine phosphate?

We use creatine phosphate as an energy storage to resupply ADP with a phosphate group as our muscle cells only contain about 2-5 mM ATP. But why doesn't the muscle cells just keep 20-30 mM ATP instead ...
1
vote
2answers
33 views

How does the placement of it's motor domain affect the directionality of a motor protein?

I'm going over some of my notes, and I have written down that motor proteins with + cytoskeletal directionality have a reversed schematic representation relative to - directed motor proteins. Then I ...
1
vote
0answers
16 views

What kind of experiments could you do to see which end of a microtubule is most dynamic?

I'm stuck between two ideas. Not sure which one of them would be best. Do a FRAP on the middle of a MT. If it grows from the + end, that section will remain dark. If it grows from the - end, ...
5
votes
1answer
111 views

Why does a “cascade” of events happen during signal transduction?

I've been watching some videos on signal transduction and it says that because there are enzymes being activated by the signal, then there is a "cascade" which happens afterwards...I don't understand ...
4
votes
2answers
133 views

Are nucleic acids found in cell membranes?

I've found various results online and I was recently marked in on an important test as wrong when I made the assumption they were not found in the cell membrane. Does anyone know what the correct ...
6
votes
2answers
81 views

Why do mitochondria fuse together?

Contrary to all of the textbook images of mitochondria that I have seen over the years, I had just learned that the mitochondria within a cell form a dynamic branching network along microtubule ...
4
votes
1answer
66 views

Membrane potential in gram negative bacteria

Does the membrane potential usually quoted for gram negative bacteria (e.g. E. coli) refer to the potential across both membranes? - If yes, then does the potential fall more over the inner or outer ...
0
votes
2answers
78 views

Difficulties understanding a pathway [closed]

I am not a biologist and I would love to understand what is going on with this pathway. I went to the description but it's still complicated, and I couldn't follow. Can someone please help me with it? ...
7
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0answers
77 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 ...
1
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1answer
308 views

How does a fertilized egg form 23 pairs of chromosomes?

I am always confused about this...so when one cell which has 23 pairs of chromosomes undergoes the two meiotic divisions it produces four cells containing 1 chromatid of every chromosome pair so when ...
8
votes
2answers
150 views

Should we induce fever to assist healing?

I am currently reading "The Fundamentals of Anatomy Physiology" 10th edition, and have found it an incredibly interesting book. I have just been reading about the lymphatic system, and the various ...
5
votes
1answer
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 ...
3
votes
1answer
77 views

How is excretion of metabolic wastes from a cell related to its size?

As with anything that is taking place within a cell, the metabolic waste too must be proportional to the size of the cell. In particular the surface area to volume ratio. But how is the waste ...
0
votes
1answer
45 views

What are iPSC cells, and what are their applications? [closed]

I also searched it on internet, and just basically know it's related to the Stem Cells, but there are too many resources, can anyone help me find out more about them, like their applications? They ...
3
votes
3answers
74 views

Can bioluminescence be used for cancer or tumor detection? [closed]

What diagnostic applications, if any, are there in using bioluminescence to detect cancer or tumors (in vivo)?
2
votes
1answer
57 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 ...
1
vote
0answers
27 views

Why can't some organisms match miRNA perfectly to the target mRNA like in plants? [closed]

What causes other organisms to be impaired in making perfect matches like plants do and is there a way to increase matching?
5
votes
2answers
89 views

What percentage of a cell's volume is occupied by protein?

I was looking at one of David Goodsell's illustrations of a cell: And it seems to suggest a very crowded picture of the intracellular environment. Just how crowded are cytoplasms? What percentage ...
5
votes
0answers
88 views

Contact Inhibition of Cell Division: Signaling Pathway

The following article refers to contact inhibition of cell division in epithelial cells, specifically MDCK cells: Collective and single cell behavior in epithelial contact inhibition. In their review ...
5
votes
2answers
125 views

Do changes in an organism's cell modify the genetic information it uses for reproduction?

What I'm actually interested about is whether a modification in one cell during the life of an asexually reproducing organism affects its genetic information? Which cell's genetic information is used ...
0
votes
1answer
2k views

What determines the size and shape of a cell? [closed]

What determines the size and shape of a cell? They differ at different tissues / organs/ species
3
votes
1answer
65 views

Expression/Mechanism of ROR1 in healthy tissue

ROR1 is currently under investigation as a therapeutic target for cancer (1). A number of studies show different cancers may have their metastatic potential reduced, or become apoptotic through ...
8
votes
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 ...
6
votes
1answer
192 views

What allows Valonia ventricosa cells to get so big?

Valonia ventricosa are single celled algae that range between one and few centimeters. In rare cases they can reach sizes exceeding 5cm. Weirdly, a lot of the literature covering these organisms ...
2
votes
1answer
216 views

Are cell lines potentially dangerous?

More specifically, if a human subject was exposed to, say, a human cancerous cell line (via intravenous injection or through an open wound, for example), is it possible that they would develop any ...
3
votes
1answer
117 views

What happens to the precursor protein's signal sequence after it is cleaved?

Where does this signal sequence "go" after it has been cleaved by signal peptidase and what is its next function?
4
votes
2answers
89 views

Name two reasons why it is impossible to determine a gene's nucleotide sequence from the amino acid sequence of the polypeptide

I can only think of one reason, which is because different codons can specify the same amino acids. However I am having trouble thinking of another reason.
1
vote
0answers
35 views

Why do restriction-modification systems work?

Some RM systems (restriction-modification systems) are plasmid-borne and are transferred through bacterial conjugation. As you all know, there are two genes in an RM system, the gene that codes for ...
2
votes
0answers
33 views

What is NK-cell compartments?

with respect to the paper: Adaptive reconfiguration of the human NK-cell compartment in response to cytomegalovirus: A different perspective of the host-pathogen interaction What is meant by ...
0
votes
0answers
21 views

alternative ways to detach cells other than trypsin [duplicate]

So I have an A549 (rather "sticky" cells, they usually take about 7 minutes to trypsinise) cells and I cannot use trypsin or tripLE as this will skew my ELISA results. I have tried scraping the cells ...