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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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 ...
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48 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 ...
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31 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 ...
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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, ...
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106 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 ...
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106 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 ...
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73 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 ...
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1answer
64 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 ...
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2answers
77 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? ...
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73 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 ...
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1answer
277 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 ...
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2answers
144 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 ...
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63 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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1answer
64 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 ...
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1answer
42 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 ...
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3answers
70 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)?
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1answer
53 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 ...
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26 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?
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75 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 ...
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78 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 ...
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2answers
113 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 ...
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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
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1answer
60 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 ...
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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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1answer
168 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 ...
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1answer
198 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 ...
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1answer
103 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?
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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.
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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 ...
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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 ...
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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 ...
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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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1answer
2k 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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1answer
351 views

What is our skin made up of?

Again, it is a basic question. What is our skin made up of? is it made up of many cells arranged in a systematic way or is it just like any layer say of a book?? what is the difference? where is the ...
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2answers
70 views

The Ancient Kingdom of Monera

Why exactly were bacteria and archaea kingdoms separated from the now unused kingdom of Monera? Aren't they the same? They are both prokaryotes, so what is the difference?
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3answers
60 views

What is the basic structure of the nuclear lamina

What gives the nucleus its shape is a mesh of intermediate filaments called the nuclear lamina. It forms an interface between the chromosomes and the inside of the nuclear envelope. If these ...
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1answer
57 views

Do cell membranes have more phospholipids in one layer than in the other?

Assuming the cell membrane to have a spherical shape, geometry tells us that the area of the inner leaflet is smaller than the area of the outer due to the difference in radius between them. Does this ...
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1answer
40 views

Detailed mechanism of the cause of diabetes mellitus type 1?

I have read in some texts that diabetes mellitus type 1 is caused by degeneration of beta cells due to our body's own immune reaction.Is it true? Can you explain further how are such types of immune ...
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9 views

Plants and animals ability to survive polypoidy conditions [duplicate]

In mammals the condition polyploidy produce something euphemistically termed "general developmental disruption" ,practically speaking this means system meltdown which happens very quickly. There is ...
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1answer
867 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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0answers
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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1answer
17k views

How to store vegetables in the refrigerator: In plastic bags or not?

My wife and I are having a debate similar to this one: I claim that it's better to take the fresh veggies out of the bags and put them in the crisper with humidity control because: That's what the ...
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1answer
26 views

How did multicellular life evolve? [duplicate]

I can imagine several specialized unicellular beings collaborating. But how does life get from that point to a unique pluricelular being that reproduces into another pluricelular being?
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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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3answers
58 views

Can a portion of human skin cells be modified in some way to generate light? [closed]

I have come across some species of living organisms who are able to emit light at whim. Can that ability be incorporated into a portion of human skin (a specialized tissue)?
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1answer
356 views

Chromosome and chromatid numbers during cell cycle phases

A diploid cell in G1 has 6 chromosomes. How many chromosomes and how many chromatids are present in each of the following stages? Here is what I am guessing G1: 6 chromosomes ; 6 chromatids G2: 6 ...
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2answers
517 views

Why do living organisms replicate itself or procreate

Why do living organisms spontaneously replicate itself or "procreate" (my understanding is that it does). From a uni-cellular and micro-organism point of view. Is there some sort of stimulant in the ...
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3answers
84 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
156 views

What is the present tense verb form of apoptosis?

For example, if I want to say something along the lines of "this signaling pathway causes a cell to go through the process of apoptosis", but I want to shorten the phrase "go through the process of ...
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1answer
50 views

What is Trypsin? [closed]

I am currently helping a PhD student in his research lab. We have been using Trypsin for the past couple of weeks but I am unsure of its purpose. I was wondering how Trypsin functioned and what it was ...