Showing posts with label Nobel winners. Show all posts
Showing posts with label Nobel winners. Show all posts

November 19 - Happy Birthday George Emil Palade

Posted on November 19, 2018

Today's famous birthday (born on this date in 1912) has been called "the most influential cell biologist ever" - and I've never even heard of him!

Romanian scientist George Emil Palade won a Nobel prize in Physiology and Medicine (along with two others). The achievement that earned him this prize is strides taken with electron microscopes, discovering ribosomes, and procedures used to study different parts of the cell and to discover how they function.

Okay, so what's an electron microscope? What different parts are in a cell? What are ribosomes? 

An ordinary microscope lights up a specimen (with, you know, light) and uses lenses to greatly enlarge the specimen. You can magnify things 4 to 2,000 times with this sort of microscope.


An electron microscope uses a beam of electrons instead of light, to "light up" the specimen, and uses electron lens systems to magnify up to about 10,000,000 times! 

With so much magnification power, we can see the super teeny tiny parts that make up our really tiny cells. These parts are called organelles (just like the parts of the body are called organs).

Notice that, in these two comparisons (above and below), the electron
microscope has way better resolution even when it is at the same
magnification as the light microscope!


 
Some examples of cell organelles include:

The nucleus - This is sort of like the cell's brain. It stores and maintains DNA and makes copies of bits of the genetic code as commands or instructions that other organelles then carry out. 


Vacuoles - These are storage compartments that usually hold water or enzymes in a watery solution. Sometimes vacuoles hold solids.

Endoplasmic Reticulum - This organelle moves molecules to and from the nucleus.

Mitochondria - These produce energy by burning sugars.

Ribosomes - These organelles build proteins.

Golgi Apparatus - This organelle changes newly-made proteins and fats, getting them ready to be stored or to be sent out to other cells.

Cell Membrane - This is like a thin "skin" that protects the cell and keeps some sorts of molecules out while allowing other sorts in.

Cytoplasm - This substance fills in the spaces between organelles and helps hold them in place.


Did you notice that ribosomes build proteins? That's a super-power you really want your cells to have! Proteins are really large molecules made of long chains of amino acids. They are the building blocks of everything from muscles to hair to skin to cell membranes. Proteins also are crucial for lots of bodily processes like digesting food.

And ribosomes are the construction crew that put together these long chains of amino acids, following instructions from the nucleus. 


Here is an animation that helps us understand how ribosomes work. This is another short video on ribosomes and protein creation - this one for younger viewers.

And here are some fun cell organelle projects. Be sure to scroll down to the "More ideas" part!
 



Make a yummy cell cake!


November 7 - Nobel Winners Born

Posted on November 7, 2018

Marie Curie's birthday is today - and she not only won a Nobel Prize, she won two! So far she is the only woman to have been awarded two Nobels.

I've already written about Curie (see "Also on this date" below)...but there have been five other Nobel Laureates born on this date! That's...impressive.

Two of these Nobel-Prize-winning birthday-peeps came from two very different places and won for two very different areas of study: Sir Chandrasekhara Venkata Raman was born on this date in 1888, in India, and won for work in physics; and Konrad Lorenz was born on this date in 1904, in Austria, and won for his work in zoology.

C.V. Raman won a Nobel for his work on light scattering. We all know that light is scattered in a willy-nilly sort of way by particles (atoms or molecules) that are smaller than the wavelength of the light. That kind of scattering affects the short-wavelength light (the blue wavelengths) the most - and that's why the sky often appears blue. BUT that's not the sort of light scattering that Raman studied. The kind we all know and love is called Rayleigh scattering after the British physicist, Lord Rayleigh, who provided the first theoretical explanation of the effect.

Rayleigh scattering is called "elastic scattering," and the energy of the light (photon) stays the same but the direction changes. C.V. Raman studied "inelastic scattering" in liquids (and also gases and solids). In this kind of scattering, some of the energy of the light (photon) is lost or increased. This kind of scattering is called Raman scattering. Scientists use this Raman effect to figure out what is in a substance without necessarily touching and therefore without damaging the substance.


Konrad Lorenz's work is probably easier for most of us to understand. He is one of the founders of ethology, the study of animal behavior. He investigated how geese and some other birds imprint - which means that they bond instinctively with the first moving object that they see after hatching. 

When Lorenz was a young person and a student, he accumulated a lot of animal pets - including some more exotic not-usually-pet animals such as a capuchin monkey. What gets me about that is that his pets lived in his parents' apartment - and if they hadn't allowed such a thing, the world might not have gained all the knowledge about animals that Lorenz discovered.

Lorenz had to interrupt his work during World War II, when he was used as a medic and as a military psychologist for the German army. (After the war, Lorenz stated that he regretted being part of the Nazi Party, the Nazi Army, or the Nazi anything!) While the war was raging, Lorenz became a prisoner of war in Russia, and he continued to serve as a medic even as a POW. He actually started writing a book while he was a Russian prisoner, and he tamed a starling (a bird) and so had yet another pet!

The ugliness of Lorenz's life and science was the ways in which he may or may not have helped the hateful and untrue bigotry of the white supremacy and white nationalism that characterize the Nazi party.

The beauty of Lorens's life and science was that he was able to discuss animal behavior within the theory of evolution by natural selection. He asked questions like - How did behavior X benefit the animal? How did the behavior make the animal better adapted to its environment and therefore better able to pass on its genes?



Thus animal behavior became more than just cute and funny anecdotes or "believe it or not" oddities - it became a scientific study.



Also on this date:





































(First full week of November)