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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23 views

Why are embryonic germ cells considered stem cells?

In a class that I'm taking we were presented 3 types of stem cells. Adult stem cells which come from bone marrow Embryonic stem cells which come from embryos Embryonic germ cells which come from ...
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1answer
130 views

Plastid and mitochondria

I am not biologist, so please bear with me for this basic question. Although I tried googling, I am confused. What is difference between plastid, chloroplast and mitochondria? Are there any plant ...
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139 views

Does increased physical activity increase the rate of cell division?

Ever since learning that the shortening of telomeres is linked to aging I've tried to figure out what causes cells to divide, and if it's possible to slow down the rate of cell division through life ...
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1answer
24 views

Polarized epithelium and localization of ion channels

I'm trying to learn more about polarized epithelial cells of the gut. I am familiar with classic brush border transporters localized to the apical memebrane to facilitate nutrient absorption. I am ...
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1answer
85 views

Amino acid profile of GPCRs

You are studying cellular signalling through a newly identified GPCR. Specifically you’re working on a pair of newly identified GPCRs, GPCR-A and GPCR-B. Each binds the same small ligand, but ...
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1answer
35 views

What can thrombosis lead to?

I am thinking this question. Thrombosis can result in organisation of thrombus, sepsis thromboembolism, fibrinoid swelling adiposity. I fibrinoid swelling (edema) (4) can occur. Also, I think (3) ...
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1answer
127 views

Solubility of Forskolin in ethanol

I am interested in using forskolin in cell culture medium. Does anyone know how to make solution of 10 microM forskolin in 5% ethanol or less. I would like to avoid using DMSO as a solvent. Thank you. ...
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3answers
150 views

Why doesn't the cytosol dissolve the polar structures?

we know that cytoplasm of cells are filled with water molecules and other hydrophilic molecules so my question is why the water of cytosol doesn't dissolve the ionic part of the lipid bilayer or why ...
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1answer
200 views

Advantage of cup-like shape of blood cells, spores?

Mold spores sometimes have the same shape as platelets in blood. If I were designing a spore it would probably be spherical. Is there any advantage to this cup-like shape? Maybe there is some ...
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247 views

Image Processing Suite for bacterial microscopy: Schnitzcells or MicrobeTracker?

I am looking to start doing some work tracking the size and growth of individual bacterial cells in the microscope. In order to analyze the images I need software that can segment the cells, ...
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1answer
140 views

Punnett square and hybrid cross [closed]

A plant breeder crossed two plants, one with red flowers, and the other with white flowers. Red is dominant. Calculate the phenotype and genotype ratios of the F2 generation of this cross. Is this a ...
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1answer
27 views

How is bacterial plasma membrane made?

Eukaryotes have ER which manufactures plasma membrane of cells. How is prokaryotic plasma membrane made ? What is the pathway and which enzymes are involved ?
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1answer
169 views

Why mosquito bite is confined to a certain shape?

I think this problem should be asked in a physiology forum rather than biology@ stackex but I'll give it a try. So my question is simple - why a mosquito bite is usually confined to a certain shape ...
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1answer
71 views

Missing 4$H_2O$s (per glucose) in Cellular Respiration… Where can they be?

I having trouble understanding the equation of the cellular respiration. The thing that bothers me is the number of $H_2O$ molecules. Generally, cellular respiration is written thus : $C_6H_{12}O_6 + ...
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1answer
697 views

How do nutrients get to the cells they need to get to?

I understand the basics of digestion. I know that nutrients get absorbed by the microvilli, enter the bloodstream and travel to the liver but after all that, what is the biological mechanism that ...
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1answer
309 views

What does it mean for a chemical pathway to be conserved?

In many papers the MAPK pathway, (along with many others) is referred to as being conserved: Example: "The mitogen-activated protein kinase (MAPK) cascades are ubiquitous in eukaryotic signal ...
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1answer
52 views

Exotic Cell Shapes

As far as I know, plant cell shapes are a difficult thing to pin down. However plant cells have cell walls and so can be very rigid. However the only plant cells I've seen have been either block ...
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1answer
58 views

Significance of lipids in biological membranes…?

Membranes are specifically designed by lipids to maintain internal hydrophilic environment in narrow range.There are hydrophobic amino acids among naturally occurring 20 amino acids and as well as ...
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1answer
56 views

Bilayer synthesis? [closed]

If we want to design a bilayer from Myristic acid (14 carbon fatty acid). The average bond length between C-C is 1.5 A. What will be average thickness of the membrane? Edited to include the OP ...
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2answers
94 views

Functioning of EDTA

I know that EDTA chelates metal ions. It weakens bacterial cell wall and inactivates the DNases. What is the reason why it can do so ? I guess it can inactivate DNases by altering the ...
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1answer
210 views

Consequence of touching Formaldehyde

I accidently touched formaldehyde some days ago. Skin on my hand got dehydrated as if I had placed it in salt solution. I washed it with water and it returned to normal state after 5 minutes. But now ...
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1answer
216 views

What causes Paresthesia (Pins and Needles) at a cellular level?

I've looked it up in plenty of places like the Wikipedia page and such, and it is clear that the most common cause of Paresthesia is either a fair amount of pressure on a specific patch of skin ...
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1answer
67 views

Structure of biological membranes?

Integral membrane proteins have functional asymmetry i.e. they have two different domains of proteins performing different functions. these proteins have Tyr and Trp amino acid residues at the ...
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1answer
45 views

Sodium-Potassium Pump

From my understanding, in the sodium-potassium pump we have Na+ inside the cell and K+ outside the cell, thus forming a so called "salted banana." After reading my textbook I found many statements ...
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1answer
73 views

Why are fibroblast used so commonly in cell biology?

Fibroblasts are some of the most commonly used cells in cell biology. What are the properties of those cells which makes them commonly used ?
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6answers
1k views

Online Molecular and Cellular Biology Video Lectures?

I am looking for video lectures to go through to guide my reading in intro molecular and cellular biology. I've had intro bio and I study evolutionary theory, but my molecule- and cell-level knowledge ...
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2answers
2k views

Is there an advantage to linear chromosomes?

The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
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1answer
359 views

What kind of a microscope do I need to see cell organelles?

I would like to study cells and looking for a microscope that would allow me to see: groups of cells individual cell cells organelles I would like to target insects and mammal tissue. I would be ...
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1answer
50 views

How do mosquitoes maintain telomere length?

While the vast majority of eukaryotic organisms maintain their chromosome ends (telomeres) via telomerase, an enzyme system that generates short, tandem repeats on the ends of chromosomes, other ...
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0answers
150 views

MTT assay normalization

Since the precise amount of cells in each well of an MTT assay varies, how can I normalize the results by cell number/concentration? How can I take into account the number of cells that have already ...
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0answers
43 views

Nearly Exhaustive List for Cholesterol Pathways [closed]

I have run across an interesting case that is similar to only two others I've encountered. What makes it interesting is the combination of undetectable (under normal testing conditions, can elaborate ...
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1answer
74 views

Gap junction turnover

Gap junction proteins, connexins, are known to form intercellular hemichannels, between two adjacent cells. These junctions are maintained cell adhesion proteins (cadherins), yet the turnover of ...
6
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1answer
271 views

Primary cilia: what cell types have non-motile cilia that migrate?

My understanding is that there are two broad categories of cilia: motile and non-motile (also called primary. Examples of the former include sperm flagella and the cilia of epithelial cells that ...
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1answer
80 views

Diffusion of FAD+

Why is NAD+ free to diffuse within the mitochondrion whereas FAD+ is not ? What biochemical properties cause this difference ?
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1answer
54 views

how cells make other macro molecules?

We know that the nucleus of the cell is the White House of the cell and its DNA is the president and it commands to make protein. So my question when DNA only codes for protein and enzymes,after the ...
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1answer
30 views

What are the effect of microtubule or microfilament inhibition on yeast expression profile?

I was wondering whether anyone has looked at what are the expression changes in yeast when the microtubule or the microfilament polymerization is inhibited? Have there been whole-genome studies?
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1answer
226 views

Benefits of CLARITY?

What are the benefits of CLARITY over this technique that was published more than a year earlier? Of course the second technique needs a fancier microscope that is likely more expensive and requires ...
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2answers
2k views

Explanation of the terms “downstream signaling” and “upstream signaling”

In molecular biology, what's the meaning of the terms "downstream signaling" and "upstream signaling"? What's the difference between them?
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2answers
72 views

Why is succinate dehydrogenase attached to the inner mitochondrial membrane?

Succinate dehydrogenase is attached to the inner mitochondrial membrane.All the other enzymes of the Krebs cycle are located in the matrix of mitochondria. What is the biochemical reason behind ...
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0answers
205 views

Microtiter Dish Biofilm Formation Assay- Pseudomonas and Crystal Violet

If Pseudomonas is a gram negative bacteria, it does not retain crystal violet but why is it that so many people are using crystal violet staining in theri Microtiter Dish Biofilm Formation Assay?
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2answers
138 views

Smoking, cancer, correlation between quitting smoking and increased immediate risk

There is "proof" out there today that suggests smoking is directly linked to cancer. I cannot argue against that, for the evidence in favor appears strong, and the evidence against is lacking. I'll ...
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1answer
334 views

What is splice junction pairs?

Splicing is a modification of pre mRNA when all introns are removed and exons are joined. What is a splice junction pair? It is two exons which connected together?
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1answer
35 views

Dinuclei cellular mechanism

I am no biologist, but I have this question buzzing in my mind. It's a matter of curiosity What happens when two nuclei occupy the same cell? Would we expect the embryo (if it lives) to have complex ...
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2answers
2k views

why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon ? Why is there a need for an initiation codon ? Can't translation start with different codons?
5
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1answer
177 views

Improving transformation efficiencies- induce supercoiling?

From my limited knowledge of science, I know transformation can be one of the hardest step in cloning, and that a large amount of research/trial and error has been done to improve on this step. I've ...
2
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2answers
60 views

Connection between genes and pathways

I am reading about a paper about inferencing pathway information in cancer cells. Authors refer to ERBB2 as a gene and a pathway. I don't have solid biology background. What exactly means when we ...
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1answer
168 views

How does human body deal with inert solid material in the bloodstream?

How does human body deal with inert solid material in the bloodstream? For example, if there is a powder of glass injected into our bloodstream, will the white blood cells do anything or will kidney ...
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2answers
95 views

How extensive is CD47?

CD47 aka the "don't eat me" signal has recently been claimed to be expressed on all tumor cells. This doesn't seem to corroborate with other cell-biology experiments. On what other cells is CD47 ...
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2answers
120 views

What is the smallest oligocelluar organism?

What is the smallest oligocelluar organism? How many cells does it have? EDIT The question is motivated by this comment@Philosophy.SE EDIT as recommended in comments I'm looking for an example of ...
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1answer
68 views

Is forced cell growth related to apoptosis?

Could an instance of forced cellular growth cause some cells to have their self-destruct mechanisms to malfunction or 'turn off'thus preventing apoptosis?