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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103 views

A photosynthesizing mouse?

N. Shubin's Your Inner Fish makes the point several times that there is a lot of functional similarity between some seemingly remote gene cousins. If that needed reinforcing we have the spider-goat, ...
3
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2answers
69 views

Cancer growth and cell division [closed]

I am confused about the prerequisites for cell division and cancer. Which of the following is necessary for the cell cycle to progress? Hormones Growth factor Cyclins Cyclin dependent kinases ...
2
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1answer
39 views

Trimming of tRNA precursors

From Molecular Biology of the Cell (4th edition) by Bruce Alberts et al. (Chp 6, Pg 338) : Both bacterial and eucaryotic tRNAs are typically synthesized as larger precursor tRNAs, and these are ...
2
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1answer
78 views

What cells don't have a primary cilium?

It is often stated that most cells in the human body have a primary cilium. Which ones don't? For which cells is it unknown?
5
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1answer
71 views

How does a Na+/H+ antiporter drive osmosis in this “osmotic motor”?

This recent paper in Cell describes a cancer cell using osmotic pressure to move in confined spaces. The cell preferentially inserts Na+/H+ antiporters in the leading membrane. I want someone to ...
6
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4answers
82 views

Exocytosis of mast cell secretory granules

I've been doing a bit of reading about mast cell degranulation and have become thoroughly lost while trying to understand how the secretory granules are actually secreted. I understand that there are ...
2
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1answer
77 views

Why are some scorpion species fluorescent under UV light?

It's known for some scorpion species such as Pandinus imperator, Heterometrus Petersii etc. to be shining under UV light. That makes them easier to capture and collect by humans. Is there any ...
2
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1answer
169 views

Why are red blood cells considered to be cells?

Wikipedia states that a cell is the basic structural, functional and biological unit of all known living organisms. Cells are the smallest unit of life that can replicate independently. It then ...
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0answers
20 views

MAPK signalling pathway initial conditions

I would like to know the initial conditions and locations of the chemical reagents in the MAPK cascasde. I'm going to plug this information into a reaction diffusion simulation. From reading ...
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0answers
33 views

How is the growth of benign tumors suppressed?

A benign tumor has an outer layer of cancerous cells beyond which are regular cells (I Think). The Tumor must have some kind of boundary layer like a wall where somehow the cancerous cells can't ...
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0answers
19 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 ...
2
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1answer
61 views

How to study the effect on tau protein isoforms on microtubule based transport?

From what I read, A-beta plaques inhibit microtubule based transport of mitochondria when tau protein is present in the cell. How would I be able to do a test to see if one isoform of tau is more ...
3
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1answer
23 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 ...
3
votes
1answer
69 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 ...
2
votes
3answers
97 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 ...
1
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1answer
65 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 ...
3
votes
1answer
45 views

How much of the jejunum is bypassed during gastric bypass?

There is both long and short limb bypass surgeries. I want to know how much of the jejunum is bypassed with each procedure.
6
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2answers
161 views

How would the human body adjust to sleep times if we were to live in a place with different day lengths?

You sleep at night and are active during the day that's how things work for humans, but theoretically if a human whose parents lived on earth were to be born in another planet resembling earth but the ...
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0answers
32 views

Cells and their characteristic properties

Could a culture of cells of a certain type be 'forced' to attain certain properties in successive generations that would have been harmful to the cell culture as they are now?
-2
votes
1answer
109 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 ...
0
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1answer
21 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 ?
3
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2answers
97 views

Can I force evolution in a group of cells by removing all the smaller cells?

I actually have algae growing in water in a container. I was thinking if it was possible to filter the water so that all the small cells will be filtered out and only the bigger ones will remain to ...
4
votes
1answer
121 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 ...
2
votes
1answer
90 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 ...
2
votes
1answer
139 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
202 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 ...
9
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3answers
2k views

Was the mitochondrion or chloroplast first?

I still don't know if the mitochondrion or chloroplast was first? I've looked for it on the internet and in various books but haven't found anything. Does anyone have the answer and a theory which ...
3
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1answer
52 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 ...
1
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1answer
59 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
82 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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votes
1answer
55 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 ...
1
vote
1answer
95 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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2answers
67 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 ...
2
votes
1answer
65 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 ...
5
votes
1answer
164 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 ...
1
vote
1answer
40 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 ...
2
votes
1answer
268 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 ...
2
votes
1answer
32 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) ...
3
votes
1answer
43 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
111 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
37 views

Nearly Exhaustive List for Cholesterol Pathways

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
50 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 ...
6
votes
1answer
67 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 ...
4
votes
1answer
26 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?
2
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2answers
911 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?
3
votes
1answer
160 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 ...
1
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1answer
72 views

Diffusion of FAD+

Why is NAD+ free to diffuse within the mitochondrion whereas FAD+ is not ? What biochemical properties cause this difference ?
0
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2answers
54 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
179 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?
0
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0answers
30 views

Macrophage death by toxin. Little balls inside cell? What type of death?

After I treated J774 cells ( a mouse monocyte/macrophage cell line ) with Clostridium difficile Toxin B (1 ng/ml for 44 hours), I noticed several small circles inside of a seemingly dead cell. I'm ...