PhysicsPushan · Class 9-10
Neeli hi kyun? Roshni ke rang, wavelength aur ek light switch
Optogenetics mein scientists neeli roshni hi kyun use karte hain, laal kyun nahi?
Socho pehle… phir dekho jawab
Kyunki channelrhodopsin naam ka protein khaas taur par neeli roshni ko sokh kar khulta hai. Har rang ki roshni ki wavelength alag hai, aur molecule apni pasand ki wavelength hi pakadte hain.
Dikhne wali roshni ek tarah ki electromagnetic wave hai. Uski wavelength lagbhag 400 nm (baingani) se 700 nm (laal) tak hoti hai. Neeli roshni chhoti wavelength wali hai, laal lambi wali.
Prism mein dispersion: alag rang alag-alag mudte hain. Baingani sabse zyada mudta hai, laal sabse kam. Isliye safed roshni VIBGYOR mein khul jaati hai. Yahi kaam baarish ki boondein indradhanush mein karti hain.
Card ki khoj: 1990s mein Hegemann ne poocha ki ek alga (Chlamydomonas) roshni ko itni tezi se kaise mehsoos karti hai. Nagel ke saath unhone channelrhodopsin-1 aur -2 dhoondhe. Channelrhodopsin-2 neeli roshni padte hi 0.2 millisecond mein khulta hai aur positive ions ko cell mein aane deta hai, yaani roshni se seedha electric signal.
So what: ek rang-specific switch ka matlab hai ki sirf woh cells on hongi jinme yeh protein hai, aur sirf tab jab sahi rang ki roshni padegi. Precise control isi se aata hai.
Ghar pe try karo
Ek table banao: VIBGYOR ke saato rang, saath mein 'wavelength chhoti ya lambi' aur 'prism mein zyada mudta ya kam'. Phir CD ya paani ke gilaas se dhoop mein spectrum dekh kar kram check karo.
Wow!
Channelrhodopsin-2 ek saath roshni ka sensor bhi hai aur ions ka gate bhi, aur woh 0.2 millisecond mein khul jaata hai!
3 sawaal
- Prism mein sabse zyada kaunsa rang mudta hai?
Jawab dekho
Baingani. Baingani (violet) sabse zyada mudta hai, laal sabse kam.
- Dikhne wali roshni ki wavelength lagbhag kitni hoti hai?
Jawab dekho
400 se 700 nm. Visible light lagbhag 400 nm se 700 nm tak hoti hai.
- Channelrhodopsin-2 khulne par kya hota hai?
Jawab dekho
Positive ions cell mein aate hain. Woh gate khulkar positive ions ko andar aane deta hai, jisse electric signal banta hai.
NCERT se jodo: NCERT Class 10 Science — maanav netra aur rangeen sansaar (dispersion, spectrum); Class 9 — tarang (wave) ki samajh