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.

learn more… | top users | synonyms

5
votes
2answers
84 views

Alternatives to trypsin for cell detachment?

I have ran out of trypsin and need to passage my cells (immortalized chondrocytes, C28/I2) today or tomorrow. I have been out of town and forgot to order more trypsin. I was wondering if there are ...
5
votes
2answers
51 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 ...
2
votes
2answers
66 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 ...
4
votes
2answers
449 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 ...
0
votes
1answer
39 views

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. ...
2
votes
2answers
28 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. ...
1
vote
0answers
26 views

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 ...
2
votes
1answer
121 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 ...
3
votes
2answers
32 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, ...
1
vote
1answer
69 views

How to estimate the DNA density in human sperm head? [closed]

I have got an estimate of sperm head volume from internet.Like consider it as a disk of order 4-5µm. Now I wanted to find the DNA density in the sperm head. How to find that?
4
votes
2answers
141 views

Breakdown of energy expenditure at the level of a single cell

The metabolic rate measures how much energy an organism expends over a unit of time. Its breakdown for the human body in terms of its functions is well documented : so much for the heart, for the ...
5
votes
3answers
282 views

Aerobic vs anaerobic respiration comparison

The following graphs compare glucose decomposition in yeasts (in anaerobic vs aerobic conditions respectively) My question is, why doesn't the first one look like a straight line as the second one ...
6
votes
3answers
133 views

What gaseous substances do humans emit?

Other than CO₂ and Methane what other gases do humans produce or emit? For example, does skin decomposition, or aerobic respiration emit any special gases that people don't normally realize or know ...
3
votes
3answers
116 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 ...
0
votes
1answer
38 views

Fruit colour related to the dissolving of pectin

What does the dissolving of pectin have to do with the colour of a fruit?
8
votes
1answer
242 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 ...
1
vote
1answer
33 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 ...
1
vote
1answer
74 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 ...
1
vote
1answer
55 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 ...
12
votes
4answers
1k views

Why would a single celled organism evolve to be multi-celled?

I read a story this week on Richard Lenski who has been 'evolving' E. coli for more than 50,000 generations now. One comment I read was from someone who doesn't accept Evolution who pointed out that ...
6
votes
1answer
71 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 ...
1
vote
0answers
27 views

recombinant peptide MHC complex

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 ...
1
vote
1answer
35 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 ...
0
votes
0answers
19 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 ...
-2
votes
1answer
46 views

What is hTAP?? Please help

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 ...
4
votes
2answers
83 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 ...
2
votes
1answer
23 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 ...
4
votes
2answers
86 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 ...
2
votes
1answer
57 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 ...
4
votes
2answers
50 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 ...
0
votes
0answers
24 views

MHC restricted peptide

What is an MHC restricted peptide? "MHC-restricted antigen recognition, or MHC restriction, refers to the fact that a given T cell will recognize a peptide antigen only when it is bound to a host ...
3
votes
1answer
107 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
votes
1answer
36 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 ...
1
vote
1answer
141 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 ...
0
votes
1answer
23 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 ...
1
vote
1answer
20 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 ...
0
votes
0answers
23 views

TAA- Tumor associated antigen

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 ...
0
votes
0answers
44 views

How does a cell compute/perceive gradients? (And which papers/books have written about this?) [on hold]

I have heard that a biological cell can perceive the change/gradient of a chemical by integrating/differentiating in some way, i.e. that the cell can do math in some way. I really don't know much ...
0
votes
2answers
35 views

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 ...
12
votes
2answers
28k views

How many human cells are there in our body, on average?

How many human cells are there in our body, on average? Wikipedia says 1013: Bacterial cells are much smaller than human cells, and there are at least ten times as many bacteria as human cells in ...
1
vote
1answer
45 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. ...
2
votes
0answers
36 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?
1
vote
1answer
73 views

What is the functional significance of the difference in cardiolipin/cholesterol ratio in different membranes?

I have read somewhere that the plasma membrane has little cardiolipin but excess cholesterol whereas the inner mitochondrial membrane is rich in cardiolipin and has little cholesterol.I just wanted to ...
3
votes
2answers
81 views

positive and negative feedback

I want to know more about positive feedback in gene regulation and what the different between positive and negative feedback is and the similarity.
2
votes
1answer
127 views

Mitochondria - are they really separate organisms that once merged into eukaryotic cells?

Theoretically, mitochondria are said to be a separate organism that is concerned with its own life and its own processes. In fact, it even duplicates individually. I know a similar question is here ...
1
vote
0answers
32 views

Is there a classification of species based on number of different cell types? [closed]

The human body has around 200 different types of cells, according to my brief internet research. How does that compare to other species? Is there a classification of species based on that, i.e. number ...
3
votes
2answers
37 views

Concentration dependent cellular processes

Are there any famous biological processes that depend strongly on a chemical concentration reaching a particular value, like some sort of switch? E.g. if concentration of chemical x reaches ...
2
votes
1answer
193 views

How do some plants grow in salt water, while others die?

My question is basically out of curiosity and comes from observing how certain plants (such as mangroves or salt cedar) can grow in seawater. If this gives the plant an advantage, why haven't all ...
8
votes
1answer
215 views

Can a bacteriophage be used to treat bacterial diseases?

Some bacteriophages reproduce using the lytic cycle which ends with the destruction of the host bacterial cell. I was wondering if theoretically this could be used theraputically to treat bacterial ...
2
votes
1answer
66 views

Inductance in cell

In an animal cell, especially neuron and in particular its axon, while there is electrical resistance and capacitance mechanism in the cell, which play essential roles in the cable theory model of ...