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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93 views

Why it seems that principles of chemistry are not being applied in this biochemical process? [closed]

According to an answer in this question, my concept used below does not apply: In the non-cyclic photophosphorylation, consider splitting of two water molecules, then 4 e- (electrons) and 4 H+ (...
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0answers
11 views

Function of NEZHA gene [closed]

What is the function of NEZHA? What effect does it have on microtubules and PLEKHA7? What happens after it has been knocked down?
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1answer
39 views

Converting miRNA names

I need to convert all of my microRNA names e.g. hsa-miR-30e-5p to e.g. entrez gene IDs, ensemble IDs or another ID. Does anyone know a good ID conversion tool for microRNAs? (I managed to convert it ...
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2answers
59 views

Structure of Cell

Are cells spheres or ovals/circles bound by phospholipidbilayer? If they are spherical how are we able to see the nucleus through the phospholipid bilayer under a microscope?
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26 views

mRNA extraction from mice ears.

I am trying to extract RNA from mice ears and for some reason I don't have RNA when I perform the electrophoresis. I directly cut the ears and I put it in a tube with a bead and trizol. then I place ...
5
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1answer
2k 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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0answers
34 views

Can the activity of bacteria be influenced by magnetism? [closed]

Some organisms are tuning their direction on a magnetic field. But are bacteria also reacting on magnetic fields and can it be used in health therapie as a kind of 'antibiotic'?
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1answer
129 views

What causes swelling after impact?

Why does the head swell after getting hit by something hard? What is the liquid that forms after impact?
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0answers
111 views

Why did multicellular organisms evolve when a single cell can survive on its own? [duplicate]

Since unicellular organisms can survive, why would there be evolution of multicellular organisms?
3
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1answer
68 views

What do proton pump inhibitors do?

I know that sodium azide and 2,4-DNPH inhibit proton pumps. The azide is called an inhibitor and 2,4-DNP is called uncoupler. I want to know what's the difference between the mechanisms of action of ...
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1answer
44 views

Normal cell diffusion in normal organism?

We know, that cancer cell can travel across an organism. Is this ABSOLUTELY impossible for NORMAL cells? For example, is it EXACTLY ZERO probability to find some bone cells inside liver or some skin ...
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1answer
55 views

Why did eukaryotic cells develop? [closed]

If eukaryotic cells can survive in extreme conditions, then why are their still prokaryotic organisms?
3
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1answer
64 views

Could a single cell be brought to life?

If a scientist is observing a single cell under a microscope, and then realizes that the cell has died, is it possible to bring that dead cell back to life? For my inquiry, let's assume that the ...
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0answers
33 views

Is it possible to make the human cells totipotent? [closed]

we all know humans are not capable of regenerating from a single cell. Is there any possibility that we can make cells totipotent?
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1answer
72 views

ADCs: by what mechanism are antibodies internalised [closed]

I read that ADCs (Antibody-Drug Conjugates) act by a -mab for a particular target being bonded to a cytotoxic compound. From my high-school-with-crayons knowledge of antibodies, however, one part of ...
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0answers
34 views

Bacteria surviving a β-lactam antibiotic

What changes can occur in the cell wall of a bacteria for it to survive a β-lactam antibiotic? I think that because a bacteria possesses peptidoglycan in its cell wall, they are β-lactam sensitive, ...
0
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0answers
22 views

What percent of cells are lysed when I make my smoothie?

This is an entirely irreverent question, but it does concern biology. I'm a physicist by training so I like to be able to estimate order of magnitude. I made a smoothie the other day with milk, ...
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2answers
352 views

Growth factors vs. mitogens

According to Campbell Biology, A growth factor is a protein released by certain cells that stimulates other cells to divide. and according to Wikipedia, A mitogen is a chemical substance ...
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2answers
208 views

Density of cells in human tissues?

Where can I find values, or estimates, of the density of cells in human tissues? Maybe an overall estimate, or distinct values for distinct tissues? Or maybe not human, but mammal tissues (which ...
2
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1answer
843 views

Difference between protein channels, protein carriers and protein pumps?

I'm revising for my biology exam and I don't fully comprehend the difference between protein channels, carriers and pumps. I know that: Protein channels do not require ATP (passive transport) The ...
3
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2answers
299 views

How many centrioles/basal bodies are there in multi-ciliated cells throughout the cell cycle?

I thought there were only two centrioles per cell, that convert to the basal body at some point during the cell cycle. I also thought there's one basal body per cilium, so I'm not clear on where the ...
3
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1answer
151 views

HOw are AMP's “recharged” to become ATP's in a cell?

I understand that after the translation stage of ribosomal protein synthesis, tRNA molecules are floating in the cytoplasm without attached amino acids until they find the correct aminoacyl tRNA ...
2
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1answer
95 views

Which step in endocytosis requires ATP?

Everybody seems to agree that endocytosis is an energy-using process, and as such requires ATP hydrolysis. However, which particular step requires it? More precisely, which 'molecular machine' ...
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1answer
62 views

How difficult is it to make a shRNA/miRNA/siRNA to silence/knockdown NaV1.7 voltage gated sodium channels in humans?

There have been various research projects that experimented with shRNA/miRNA/siRNA to specifically silence/knockdown NaV1.7 voltage gated sodium channels in small animals like rats & guinea pigs. (...
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12 views

Do you know of any scratch assay video databases?

It would be of great help for a statistical work we have been asked to carry out at our University. Thank you very much in advance.
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1answer
55 views

Do snRNAs exit the nucleus or not?

In Molecular Biology of The Cell (Alberts, et al., 2015), it lists the various RNAs that are trafficked through the Nuclear Pore Complex (NPC) into the cytoplasm. The list includes snRNAs, but I ...
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2answers
307 views

At any given moment, how much energy is stored in the human body as ATP?

At any given moment, approximately how much energy is stored in the human body as ATP in the ADP-P-bond? This of course depends on what type of cell it is and the activity of the individual in ...
3
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1answer
68 views

Can a cell start a mitosis if it lacks energy or molecules to complete it?

I'm wondering whether a cell can start a mitosis if it lack molecules or energy to fully complete it. From what I'm reading on wikipedia the cell passes most of its time in the interphase in which the ...
3
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1answer
43 views

What is the purpose of requiring two separate binding systems for the antibody response?

I've read that in most cases, B-cell activation requires helper T-cells. This requires antigen binding by both antibodies and T-cell receptors, using two different antigen-binding proteins, ...
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2answers
48 views

At which end does polymerization of microtubules occur?

My book says that polymerization and depolumerization of microtubules occurs on the + end however, I've found a note that says that depolymerization occurs on the - end. I need help please :) thank ...
4
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1answer
52 views

Is HSV-vector-mediated miRNA expression in dorsal root ganglia stable?

My question is on the following article: "Reduction of voltage gated sodium channel protein in DRG by vector mediated miRNA reduces pain in rats with painful diabetic neuropathy" My question is, do ...
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0answers
30 views

Effects of pH vs membrane potential within a cell? [closed]

How are these two concepts related? Does changing each result in the same effects? As in: what kind of reactions/processes would be affected if we changed the pH within a cell? Would the results ...
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2answers
93 views

In cell division, are daughter cells identical?

I understand that after a cell replicates, there will be two daughter cells instead of one. But wouldn't one of them be the old cell that created the second one? The old cell having gone through G0, ...
5
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1answer
39 views

Constant or variable number of chiasmata during recombination?

During recombination, is the number of chiasmata consistent for each gamete and are the chiasmata regions consistent within a single organism?
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1answer
210 views

Do human somatic cells have 46 chromosomes all the time?

As far as I know, a human somatic cell has the cell cycle: Interphase and Replication (mitosis). In interphase the cell has 2 growth phases (G1 + G2) and a synthesis one (S phase being in between G1 ...
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18 views

How sorbitol treatment selects ring stage of plasmodium falciparum

I would like to know the basic chemistry behind ring stage selection by sorbitol. Sorbitol is used for Synchronising the plasmodium culture in ring stage. How the chemical retains or selects ring ...
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1answer
56 views

Are nucleotides at the ends of DNA stripped on aging?

I had the following understanding (now after reading a popular science article seeming wrong understanding): DNA in (regular) cells (in human and some other organisms) are protected by telomers. ...
1
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1answer
53 views

cell specialisation and their location

When we create new cells, how come they are of the 'right' type at the 'right' place? For example, when I make a new cell on my lips, it's obviously not the same as a new one in my kidneys. Is the ...
0
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1answer
57 views

Common genes and enzymes involved in pathogen entry into host

Many microbes like Salmonella, E.coli, Legionella pneumophila etc. enter host cells via cystoskeleton remodeling of the host cell. Do all microbes follow the same path or there are any other ways for ...
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2answers
2k views

Book Recommendations: GRE Subject Test In Biochemistry, Cell And Molecular Biology

There are probably a lot of really good answers that may vary significantly in terms of content. I'm looking for a set of books that I can read in preparation for the GRE Subject Test In Biochemistry,...
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0answers
302 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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0answers
17 views

Ions in different cell compartments

I would like to understand the distribution of metal ion concentrations (such as Mg2+) in the different cell compartments. I tried very hard but still couldn't find such information. Could anyone help?...
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2answers
75 views

Anaphase Microtubule Disassembly

Centromeres move toward the poles as the microtubules that connect them shorten. This shortening is due to the removal of tubulin subunits from the kinetochore ends of the microtubules. I'm confused ...
0
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1answer
66 views

Which steps occur in each phase of Meiosis and Mitosis [closed]

MITOSIS In mitosis am I correct in saying that the spindles attach to the centromeres at the end of prophase/prometaphase? (I read this in an answer to another question) MEIOSIS Does the ...
0
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1answer
52 views

Why only mitochondria and plastids?

Why are there only two unique semi-independent organelles? Why are there no others, symbiogenesis seems like it should be a relatively common thing. So do most organelles just lose all their DNA? Or ...
9
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2answers
7k views

Why is saltatory conduction faster than continuous conduction?

How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental ...
0
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1answer
36 views

How chameleons change color? [closed]

Well, I was watching a video about chameleons and I saw that their cells can change color. Can someone explain me how is this possible?
4
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1answer
91 views

How much of the jejunum is bypassed during gastric bypass?

There is both long and short limb gastric bypass surgeries (along with several other variations on intestinal bypass procedures). How much of the jejunum is bypassed with a long-limb and short-limb ...
0
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2answers
211 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 within the matrix of mitochondria, though. In biological systems, there ...