what are the roles of carotene & xanthophyll in leaves??

Question

oh, n' why do many leaves change color in fall??

Answer 1

In fall it gets colder, days shorten and the chlorophyll breaks down and is not replaced as the plant prepares to go dormant. The carotenoids remain functioning longer so are revealed.
Carotenoid functions include;
They collect light in the wavelengths chlorophyll can’t then transfer it to chlorophyll.
They also absorb excess light energy and dissipate it in order to avoid damage to the plant these are the Xanthophylls.
They appear to have a role in sensing blue light, which is involved in opening stomata and in phototropism.
They are free radical scavengers.
They become fragrant. Breakdown products of carotenoids are part of a rose's odor.
There are over 600 known carotenoids so there are probably more functions.

Further red leaf color comes because the leaf begins producing anthocyanins in the fall to deter herbivores as well as shielding the plant from UV damage now that the chlorophyll is gone. They are found in stems, and roots as well so there are more functions not yet known for the more than 500 anthocyanins.

Answer 2

Carotene and xanthophyll are secondary pigments in leaves that broaden the range of light wavelengths that chloroplasts can exploit in photosynthesis. Because they reflect different colors than chlorophylls, they also absorb different colors, meaning that a plant leaf can extract more energy from sunlight than it could with chlorophyll alone.

Deciduous leaves change color in fall because the plant is shutting down its photosynthetic functioning for the winter. During winter, the Sun is lower in the sky and less direct sunlight is available for photosynthesis. Maintaining green leaves would be a liability to the plant: the leaves aren't producing much glucose, yet they still require ATP to stay alive. When the plant stops maintaining the leaves, chlorophyll quickly breaks down (and is not replaced). The green color fades, and the reds and yellows of carotenes and xanthophylls, which were previously masked by the green of chlorophyll, emerge.

Answer 3

YES. 1. Lasers do the exact same thing. They keep continuously generating light, increase its strength and release bursts of the high intensity (high energy ) light. So they store the light energy for fractions of seconds. 2. Beyond the laser realm, the only way to store light would be to build a trap of either A. Electromagnetic Frame like used to store the plasma state of matter or B. Gravitational field. The first one hasn't been done for light yet. The secondone needs mass of atleast 4 suns cooled down without any atomic reactions - e.g. black hole.

Answer 4

google it
but leaves change in the fall because of the lack of water during winter so in order to conserve water trees drop thier leaves and that is what causes them to change colors.

Answer 5

We learned this last year in biology.

Just google it, unti more people answer...I don't remember.