Login

Join for Free!
118340 members


Starch

Discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field.

Moderator: BioTeam

Starch

Postby thesloc » Sat Sep 30, 2006 9:27 pm

Hello all, I'm new to the forums and I've found a plethora of helpful individuals.

My question is concerning starch.

"The breakdown of starch is often catalyed at very high temperatures (100C). Why is the high temperatue needed?"

I'd appreciate any given help, in detail.


--Thanks.
thesloc
Garter
Garter
 
Posts: 3
Joined: Sat Sep 30, 2006 9:24 pm

Postby Dr.Stein » Sat Sep 30, 2006 9:59 pm

Are you sure it is digested/degradated or catalyzed at water-boiling temperature? ;) I think the suitable temperature for digestive system is around body-temperature, which digestive enzyme will work properly. In 100 oC enzymes are damaged so the digestion will not carried out as it should be.
Image
User avatar
Dr.Stein
King Cobra
King Cobra
 
Posts: 3501
Joined: Thu Jul 07, 2005 7:58 am
Location: 55284 Yogyakarta, Indonesia

Postby kjle » Sun Oct 01, 2006 2:52 am

enzymes will denature usually at about 45°C, I think you may be thinking fahrenheit

100°F is much closer to body temperature (98.6°F)
- disarm you with a smile

Founder of "Photography Club"
Member of "Truth-Seekers" tribe

#1 posts/day total
#8 total post count
User avatar
kjle
King Cobra
King Cobra
 
Posts: 1950
Joined: Sun Sep 10, 2006 10:10 am
Location: Vancouver, Canada


Postby thesloc » Sun Oct 01, 2006 3:20 am

Hey thanks. The question does say it's Celsius, not Fahrenheit. So I believe the question is a trick question. Now, does anyone know the method by which starch breaks down? Or any idea how I can elaborate further on my question?


How do starch breakdown in the absence of functional enzymes?

I think my problem has something to do with overcoming the activation energy and heat.
thesloc
Garter
Garter
 
Posts: 3
Joined: Sat Sep 30, 2006 9:24 pm

Postby victor » Sun Oct 01, 2006 4:40 am

Starch hydrolysis actually can be done by just heating it with water, as you said, in 100 ºC. But the problem is...how long can you wait for that? keep re-adding water to change the evaporated water vapor and do the iodine test oncee in every 10 minutes......

I ever tried this kind of hydrolysis about 3 days ago. it's an acid catalyzed starch hydrolysis. Just imagine that, 10 mL starch solution, added with 3 mL HCl 3M and heated about 70-80 ºC.....it still need about more than 36 minutes to do a nearly complete hydrolysis...(because I use an iodine test to detect the hydrolysis, while achroodextrine, maltose and glucose share the same result of that test, so I can't say that's a complete hydrolysis of starch).

Breakdown of starch by fuctional enzymes is done by α-amylase and β-amylase. Breakdown by alpha one yields maltose and dextrine, while breakdown by the beta yields maltose. And yes, this enzyme catalyzed breakdown can't be done in 100 ºC due to denaturation by heat.

So, I can say that, if the breakdown of starch is in 100 ºC temperature, it must be acid catalyzed hydrolysis.

@Dr.Stein
Majority enzymes will get denaturated in high temperature but certain enzymes like taq-polymerase and cellulase can stand that heat...:D
Q: Why are chemists great for solving problems?
A: They have all the solutions.
User avatar
victor
King Cobra
King Cobra
 
Posts: 2668
Joined: Sat Apr 30, 2005 12:01 pm
Location: Yogyakarta, Indonesia..

Postby thesloc » Sun Oct 01, 2006 4:54 am

Thank you Sir.

Something more political:
"In the United Staes, the use of high-fructose syrup dramatically increased after the take-over by the communist regime in Cuba. How can the two events be related?"

Thanks, once again, for any help.
thesloc
Garter
Garter
 
Posts: 3
Joined: Sat Sep 30, 2006 9:24 pm

Postby victor » Sun Oct 01, 2006 5:03 am

who's you calling by 'Sir'? :?
Q: Why are chemists great for solving problems?
A: They have all the solutions.
User avatar
victor
King Cobra
King Cobra
 
Posts: 2668
Joined: Sat Apr 30, 2005 12:01 pm
Location: Yogyakarta, Indonesia..

Postby Dr.Stein » Sun Oct 01, 2006 1:32 pm

victor wrote:@Dr.Stein
Majority enzymes will get denaturated in high temperature but certain enzymes like taq-polymerase and cellulase can stand that heat...:D

Oh ok, enzyme is not my major, I do not know any exceptions :oops: thank you for telling me this :)
Image
User avatar
Dr.Stein
King Cobra
King Cobra
 
Posts: 3501
Joined: Thu Jul 07, 2005 7:58 am
Location: 55284 Yogyakarta, Indonesia

Postby canalon » Sun Oct 01, 2006 4:26 pm

Think agricultural producton of cuba. Tobacco is not the oly thing...
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
User avatar
canalon
Inland Taipan
Inland Taipan
 
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Postby mith » Sun Oct 01, 2006 5:27 pm

High fructose syrup is made from corn
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr
User avatar
mith
Inland Taipan
Inland Taipan
 
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN

Postby MrMistery » Sun Oct 01, 2006 6:38 pm

and cuba grows sugar..
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)


Return to Molecular Biology

Who is online

Users browsing this forum: No registered users and 7 guests