October's Off and Running!
Awesome long three-day weekend was had by all. Still feels like summer, a lot of light and fresh air activities. On Tuesday, we increased our healthy habits with morning OT exercises.
SOMETHING NEW SOMETHING DIFFERENT:
 |
| Alec sharing his meeting with Boston college students |
Pathways Science Friday!
Answer:
The simple answer is this: Leaves fall off trees so that the trees can survive the winter.
But the word “fall” is a bit misleading. It implies that the trees are passive this time of year, when, in fact, they are actively “pushing” the leaves off their branches.
We answer this question with help from NPR.
2. Why do leaves change color?
Answer:
“The chlorophyll—which gives leaves their green color—begins to break down, allowing for the masked pigments to show up.”
“The chlorophyll—which gives leaves their green color—begins to break down, allowing for the masked pigments to show up.”
GREEN
Cloroplasts are the organelles inside leaves responsible for photosynthesis,
when plants turn light into sugars. The distinct green pigment is called
chlorophyll, which literally means “green leaf” in Greek. When a plant is alive
and well, the green pigments visually dominate, but underneath that cool green
color lies other pigments called . . . carotenoids.
when plants turn light into sugars. The distinct green pigment is called
chlorophyll, which literally means “green leaf” in Greek. When a plant is alive
and well, the green pigments visually dominate, but underneath that cool green
color lies other pigments called . . . carotenoids.
YELLOW & ORANGE
Carotenoids are another kind of pigment that live in the chloroplasts of tree
leaves, as well as other plants like carrots, bananas, corn and daffodils. That
bright yellow-orange color is always present in the leaf, but only becomes
visible when the green chlorophyll begins to die and becomes colorless. Longer
and colder nights trigger this process, “erasing” the green and exposing the
subtler yellow and orange colors beneath.
leaves, as well as other plants like carrots, bananas, corn and daffodils. That
bright yellow-orange color is always present in the leaf, but only becomes
visible when the green chlorophyll begins to die and becomes colorless. Longer
and colder nights trigger this process, “erasing” the green and exposing the
subtler yellow and orange colors beneath.
RED
Red leaves derive their brilliance from pigments called anthocyanins, which
usually only form after the onset of autumn, from sugars inside the cell sap.
These are the same red pigments that color cherries, grapes and apple skins,
and in leaves, they might appear as red, pink, purple or even dark blue. While
warm, sunny days increases sugar production (more red), autumn’s cold nights
close up the leaf’s vein structure, preventing the red color from flowing back out
or spreading across the leaf. That’s why vein patterns are highly visible or
colored differently in red leaves.
usually only form after the onset of autumn, from sugars inside the cell sap.
These are the same red pigments that color cherries, grapes and apple skins,
and in leaves, they might appear as red, pink, purple or even dark blue. While
warm, sunny days increases sugar production (more red), autumn’s cold nights
close up the leaf’s vein structure, preventing the red color from flowing back out
or spreading across the leaf. That’s why vein patterns are highly visible or
colored differently in red leaves.
BROWN
One more color comes into play in fall—and that is brown. After leaf cells die
and break down, the natural process of decomposition takes over, producing
bitter chemical compounds known as tannins. Oak leaves are rich in tannin, as
are tea leaves and grape leaves (hence high concentration of tannins in tea and
red wine). A cold, wet, and overcast fall speeds up the tree leaves’
decomposition process, causing the less glamorous brown foliage.
and break down, the natural process of decomposition takes over, producing
bitter chemical compounds known as tannins. Oak leaves are rich in tannin, as
are tea leaves and grape leaves (hence high concentration of tannins in tea and
red wine). A cold, wet, and overcast fall speeds up the tree leaves’
decomposition process, causing the less glamorous brown foliage.
Comments
Post a Comment