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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6
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2answers
645 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
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 ...
2
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2answers
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 ...
0
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1answer
59 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
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. ...
2
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0answers
34 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
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1answer
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 ...
2
votes
1answer
719 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 ...
3
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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, ...
1
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1answer
97 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?
3
votes
1answer
81 views

Hela live cell confocal laser scanning - reccommendations for good fluorophore that will show good movement

I've been doing a lot of live cell imaging lately mostly using hela cells expressing some EYFP based chimeric proteins. I'm building a video library for an art student here at the university who is ...
5
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3answers
393 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
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3answers
149 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 ...
0
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2answers
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 ...
3
votes
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 ...
0
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1answer
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?
8
votes
1answer
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 ...
2
votes
1answer
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 ...
3
votes
1answer
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 ...
1
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2answers
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 ...
1
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1answer
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 ...
1
vote
1answer
104 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 ...
6
votes
1answer
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 ...
1
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0answers
32 views

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 ...
1
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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 ...
-2
votes
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 ...
4
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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 ...
7
votes
1answer
2k views

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? ...
2
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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 ...
9
votes
1answer
733 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 ...
4
votes
2answers
372 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
347 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
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 ...
3
votes
1answer
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... ...
4
votes
1answer
3k views

Rate of cell division in humans

On average, how many cells divide each day in a human being? How long does a cell wait before dividing itself ? I have tried to look on the internet but surprisingly the answer is difficult to ...
3
votes
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 ...
1
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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 ...
2
votes
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 ...
1
vote
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 ...
1
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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 ...
0
votes
2answers
43 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 ...
1
vote
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).
12
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2answers
34k 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
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. ...
3
votes
0answers
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?
1
vote
1answer
115 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
1answer
352 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 ...
3
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2answers
41 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
373 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
222 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 ...