Yuqian Xing Minh Duong Xiao Liu Julia Zhao Department of Chemistry University of North Dakota Grand Forks ND 58202 Nature Sunday Academy 20152016 Nanotechnology and Biotechnologyproject 2 ID: 931184
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Slide1
Why Does Hair Turns to Gray
Yuqian Xing, Minh Duong, Xiao Liu, Julia ZhaoDepartment of Chemistry, University of North DakotaGrand Forks, ND 58202
Nature Sunday Academy, 2015-2016
Nanotechnology and Biotechnology-project 2
Slide2Slide3Variety of the Hair Colors
Hair colors are associated with ethnic groups and can be separated into 6
kind
s:
Blond,
Blond brown,
Brown,
Brown black, Black, Red.
How many colors for human hair?
Slide4Pigment: melanin
What decide the hair colors?
Various amounts and ratios of two different types of melanin result in the variety of the hair colors
Molecular Structure
of
eumelanin
Black and brown eumelanin
Slide5The reason which causes hair color to turn gray when people get older is the alteration of melanin level.
New research discovery:
H
2
O
2
Any other reason?
Slide62 H
2O
2
→ 2 H
2
O + O
2
CatalaseKnowledge about enzyme?
The other main reason
of
achromotrichia
(hair turn gray) is the reduction of catalase synthesized when people aging, which causes the accumulation of H
2
O
2
in hair follicle.
Slide7Experimental activity 1-Hair in H
2O2
Step 1: Prepare three empty clean vials
.
①
③
②
Slide8Step 2: Add 20 ml of solution to each vial
. ①
and
②
are 1M H
2
O2; ③ is pure water, used as a negative control.
Experimental activity 1-Hair in H
2
O
2
Slide9Step 3: Add 100
μl catalase to vial
②
gradually and
slowly. It is obvious to see the bubbles generated in the solution.
Experimental activity 1-Hair in H
2
O2
Slide10Step 4: Wait for about 10 minutes until little bubbles observed in the vial, then put the hairs in each vials.
Experimental activity 1-Hair in H
2
O
2
Slide11Step 5
: After 2-3 hours incubation, color fading of hair is observed in vial
①
only
.
Experimental activity 1-Hair in H
2
O2
Slide12The reaction is slow. If goes to 24 hours, the results will be:
Experimental activity 1-Hair in H
2
O
2
Slide13Step 1: Prepare three vials with 20 ml of dye solution.
1a
3a
2a
Experimental activity 2- Color bleached by H
2
O
2
Slide14Step 2: add 100
ul
catalase to vial 2 and 1ml H
2
O
2
to vial 1 and 2.
1a3a2a
Experimental activity 2- Color bleached by H
2
O
2
Slide15Factors may contribute to gray hair
StressLife style: nutrition, sleep well…
Reduce stress and live in a health life style