Biology Stack Exchange
Biology Stack Exchange

Questions tagged [cell-biology]

The study of cells and their physiological properties, structure, environmental interaction, division, life cycle, and death, as well as the organelles they contain. Also known as cytology.

The cell is the basic functional unit of all known life forms, and it is the smallest unit which can replicate independently. Cells are bound in membranes and filled with cytoplasm. They contain a variety of molecules, structures, and organelles, and they perform a variety of functions. Cell biology is a broad field so relevant complementary tags should also be considered.

1703 questions
38
votes
1 answer

How does a cell sense its size?

Cells come in all sorts of sizes. How do they regulate their cell size to the point where similar cell types have a fairly mono-disperse size distribution? Reasked from http://www.quora.com/How-Does-a-Cell-Know-Its-Size
bobthejoe
  • 7,867
  • 7
  • 43
  • 73
16
votes
1 answer

Does electricity cause damage on a cellular level?

As I understand it the mechanism of death when a mammal is electrocuted is that the current disrupts the SAN/AVN in the heart causing it to fibrilate or arrest. That's on a macro scale, however. What damage, if any, does electricity cause on a…
Rory M
  • 13,479
  • 9
  • 56
  • 96
14
votes
3 answers

Do animal cells have vacuoles?

I overheard a rather heated argument about whether or not animal cells have vacuoles. One person said that they do, but they're much smaller than vacuoles in plant cells. The other person said they don't. While there is something there that acts…
Melanie Shebel
  • 303
  • 1
  • 2
  • 15
9
votes
2 answers

Why can't a human regenerate limbs like some other species?

When a person's arm is amputated, the arm will no longer be able to grow back. However, in salamanders, the arm actually grows back. In comparison to a human, what is really happening to the cells in the wounded area in salamander ?
IxariusSci
  • 141
  • 4
9
votes
2 answers

How much energy does a cell expend maintaining its contents?

In software engineering, an analogy is sometimes made using biological cells. I would like to know whether it has basis in fact. People say (Alan Kay was first) that "objects" in software should be like cells: separate from one another,…
Nathan Long
  • 191
  • 1
  • 5
8
votes
2 answers

Are there human cells, apart from red blood cells and platelets, without a nucleus?

I know that blood platelets and erythrocytes do not have a nucleus. Are there more cells in the human body without a nucleus, such as pancreas, cartilage, or lung cells?
Ace
  • 103
  • 1
  • 1
  • 7
8
votes
1 answer

What is the H+ gradient in mitochondria?

I would like to understand what the term H+ Gradient means. I googled this question and found terms such as chemiosmosis and ion gradient being tossed around. I am very new to biology and I do not know any advanced terms or anything of the like.…
Sciiiiience
  • 345
  • 1
  • 2
  • 6
7
votes
1 answer

How do red blood cells survive without a nucleus?

I was reading this question Why do mammalian red blood cells lack a nucleus? According to my understanding, a nucleus is the cell's control center (like the brain). All the functions in the cell are carried out according to the nucleus's…
MartianCactus
  • 221
  • 1
  • 2
  • 7
7
votes
3 answers

Intrinsic apoptosis in erythrocytes

With a lack of mitochondria, can red blood cells perform intrinsic apoptosis and do they have another way of generating cytochrome c to attach to a CARD domain and assemble the apoptosome? Or are they dependent on killer lymphocytes to bind via the…
Frank
  • 453
  • 2
  • 8
7
votes
1 answer

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 connexins is fairly rapid. As these connexins are…
user560
6
votes
1 answer

Are there oligocellular organisms in nature and, if so, what are they like?

I'd think protozoans can be oligocellular, but I haven't found any examples, and I'm curious to know what is the minimum number of cells an organism can have other than a single cell.
Vic Goldfeld
  • 161
  • 2
6
votes
2 answers

Advice on Cell Biology texts by Alberts

I am currently reading "The Chemistry of Life" by Rose. It's a great book (to me as a lay reader at least) and an interesting topic so I am interested in pursuing some of the further reading he suggests. The first book he mentions in the…
Steve
  • 193
  • 1
  • 6
6
votes
1 answer

Are There Exceptions to Animal Cells not Having Cell Walls?

In the January Issue of SciAm (discussing Haemophilia): When damage occurs to blood vessels, exposure of the blood to collagen in the cell walls and material released by the cells triggers the activation of clotting factors. I read the original in…
geometrian
  • 183
  • 6
5
votes
2 answers

How does ubiquitin recognize misfolded proteins?

Misfolded proteins are tagged by ubiquitin and then are destroyed by proteasomes. How does ubiquitin know which protein to tag?
user3893
  • 171
  • 1
  • 3
5
votes
1 answer

How does sugar enter neurons if they don't use insulin?

I heard somewhere that as opposed to other cells, neurons do not use insulin to get their sugar supply. Why is that? What is the alternative mechanism? I assume sugar can't just enter the cell without some kind of help from a protein, is that true?
Uri
  • 349
  • 2
  • 8
1
2 3
…
9 10