5 ms·
Cell size and scale
- mrshoe 17y agoThat zoom effect is great. It reminds me of the ZUI (zooming user interface) described in Jef Raskin's book, The Humane Interface. Oh how I wish someone would build a desktop OS with a ZUI.
- cloudkj 17y agoAlso reminds me of Seadragon from Microsoft Research.
- ugh 17y agoI didn’t know that chromosomes are so big. The photoreceptor (or sperm, for that matter) seems way too small to fit 46 (23). What am I missing?
- araneae 17y agoDNA only exists in the form of chromosomes at particular parts of a cell's life (namely, cell division) and is a highly organized structure consisting of DNA and of proteins. Neither sperm nor photoreceptors undergo cell division, so for all its existence its DNA exists in an undifferentiated mass inside the cell. DNA is long, but skinny, so it compacts quite nicely.
- ugh 17y agoCool. But that also means that photoreceptor cells and sperm divide from cells quite unlike themselves, right? Or does that work differently?
- amoeba 17y agoStem cells are totipotent and can give rise to any type of specialized cell in your body. Cell signaling induces horribly complex signaling pathways that lead to profound changes in transcription of that cell's DNA. As an embryo, your gonads start in your chest and, through signals from your brain, end up in your pelvic region. Erythrocytes (Red blood cells) are a great example of specialization. Before they become erythrocytes they have a nucleus. Their nucleus is ejected, their shape completely changes from spherical to flat-with-a-dimple and they are not a red blood cell. Obviously, erythrocytes cannot divide.
- ugh 17y agoThanks for the explanation!
- amoeba 17y agoCells are great. You're welcome.
- kirubakaran 17y agoNo wonder you, amoeba, think so.
- araneae 17y agoSpiders are better.
- lsb 17y agoIt's like a choose-your-own-adventure version of the Eames Brothers' "Powers of Ten" movie!
- camccann 17y agoA carbon atom is bigger than a water molecule? Interesting. Speaking of the carbon atom, there is no way that what seems to be its nucleus is even remotely to scale.
- amoeba 17y agoBest I can tell, they have it wrong. They might be interpreting size differently than I expect but Carbon should be around 220pm and Water around 310pm. Rough estimates for diameter are based on molecular mass and density; density being variable. I'm curious how they did their calculations.
- araneae 17y agoI'm not sure if it's actually wrong, but rather a function of how they draw atoms versus molecules. Diameter is a funny concept for atoms and molecules because electrons orbit at different distances around the nucleus probabilistically. The depiction of this carbon atom I think represents this, with the lighter color areas denoting areas of lower probability. However, drawing such a diagram for a molecule isn't very pretty, because the orbitals for each atom in the molecule overlap. They probably drew the water molecule using intermolecular distances, and then filled in the distances so that each atom was a sphere. In actuality the electrons are found with some probability outside this area.
- amoeba 17y agoIf they're drawing Carbon with respect to its orbitals then they are completely wrong. Carbon has both S and P orbitals whereas water has hybridized orbitals. This would mean both their carbon and water are drawn incorrectly.
- araneae 17y agoActually, as I look at carbon more closely, that's exactly what they're drawing. The inner circle (s orbital) has two yellow dots (electrons) on it, and the outer circle (p orbital) has 4 yellow dots. It does look like they totally ripped off this lady's drawing though: http://www.dorlingkindersley-uk.co.uk/nf/ClipArt/Image/0,,_1584216,00.html http://www.dorlingkindersley-uk.co.uk/nf/ClipArt/Image/0,,_1... Clearly they aren't drawing the orbitals for water, which I already stated. But you're right, carbon is probably too big. Wolfram alpha says the diameter of carbon is 134pm, and we all know WA is right about everything.