Tuesday, September 17, 2013

Music and Quantum Physics

This is by far the coolest musical thing I've seen since Pi Day (post including video of a musical representation of Pi).  And this is so much more epic, because it's hard core science!




By the way, I don't understand any of this, but the song is wicked awesome. Some day perhaps I'll have a handle on Physics, but it is not this day. Please share this video, it's great and I hope it goes viral!

Wednesday, September 4, 2013

Plastids

Plastids
Plastids are organelles that are unique to plants.  There are several different types with different functions.  Here is a quick visual overview of the types:

I won't go over the developmental stages of them (proplastid, etioplast), but we'll cover the other types.
 
Chloroplasts
These are what give a plant its green color because they are full of thylakoids busy doing photosynthesis.  They absorb all kinds of light except green and turn it into ATP.  Since green is the light reflected back, that's what color they look to us.
These pictures came out a little bit blurry, but they are taken from a water weed leaf slide we prepared ourselves in lab.  All the green dots everywhere are chloroplasts.





Inside a chloroplast:
  • thylakoids- where photosynthesis (light reaction) happens (the thylakoid is full of electron transport chains and ATP Synthase, same as in animals.  Click here for a post about the electron transport chain and ATP Synthase.)  Thylakoids are organized into:
    • grana - stacks of thylakoids
    • frets - intergranal thylakoids (in other words, thylakoids that are hanging out between the stacks)
  • stroma - spaces outside the thylakoids.  This is like the "cytosol" of the chloroplast.  The Calvin cycle (dark reactions) take place here.

Chromoplasts
These are like chloroplasts but aren't green.  They make and store pigments.  Here you can see the orange specks are chromoplasts from a carrot:

And some red ones from a tomato:

Leucoplasts
Leucoplast is a category of plastids which aren't pigmented.  Leuco means "white". They are storage for various types of organic molecules.  The types are amyloplasts, Elaioplasts, and Proteinoplasts, discussed below.

Amyloplasts
Amyloplasts store starch (food storage form of carbohydrates/ sugars in plants).  The tiny purple speckles in the middle of the picture are the amyloplasts which have starch crammed inside.  They are purple because they've been stained, otherwise we couldn't see them.


Elaioplasts/ oleoplasts
Elaioplasts store lipids. Here are some from an avocado:


plantbiology,siu.edu
Proteinoplasts
Lastly, proteinoplasts store - you guessed it - protein.  I couldn't find a picture that I had confidence actually represented a proteinoplast rather than any of the other types of leucoplasts.  According to wikipedia, not much research has been done on proteinoplasts specifically, in the last 25 years.  Which would explain why I can't find pictures.  You can use your imagination. :)

Stay curious.
-Julie

Tuesday, September 3, 2013

Plant cells

The pictures on this blog post are all my own, taken through a microscope, sorry not all of them are the best quality.  But at least I don't have to collect links to sources!

Mitochondria- the largest dark dots are the nucleus, but you can see lots of little dark purple spots which are the mitochondria.  This is from a prepared slide of an onion root with a special stain for seeing mitochondria, and a brown stain for cell walls.

Chloroplasts
These look quite blurry, it's just because there are multiple layers of cells superimposed on one another.  This was a hand mounted water weed leaf.  All the little green speckles everywhere are chloroplasts- the organelles which house thylakoids for conducting photosynthesis. :)


Chromoplasts
These are like chloroplasts, but they are not green.  They are still colored though, hence the name chromo ("color") plast.  You can make out the little orange specks from a carrot:

And tiny red specks from a tomato:

Amyloplasts- these are a type of plastid that contains starch storage.  The tiny purple granules are the ones.  They're only purple because a stain was added to this potato so you could actually see it.






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