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Digestive system

PLEASE CAN SOMEONE PROVIDE ME WITH A LOGICAL EXPLANATION ANSWERING THE QUESTION.
Different parts of the human digestive system help to break down molecules of fat so that they can be absorbed into the body.

Describe how.
To gain full marks you should refer to:

the enzyme and where the enzyme is produced
the products of digestion
any other chemicals involved.

ALL I KNOW IS THAT LIPASE IS PRODUCED AT THE PANCREAS AND SMALL INTESTNE AND BREAKIN DOWN INTO GLYCEROL AND FATTYACIDS. also THAT THE LIVER PRODUCES BILE WHICH SOMEHOW MULSIFIES FATS.. I NED HELP WITH MAKING A LOGICAL ANSWER SO I CAN REVISE FROM IT AND SEE WAT A 6 MARK ANSWER LOOKS IKE.. PS MY KNOWELEDGE MIGHT NOT EVEN LINK TO THE Q- THIS IS JUST WHAT MY RESPONSE WAS.. THANK YA FOR YA HELP X
Original post by artymaniac
PLEASE CAN SOMEONE PROVIDE ME WITH A LOGICAL EXPLANATION ANSWERING THE QUESTION.
Different parts of the human digestive system help to break down molecules of fat so that they can be absorbed into the body.

Describe how.
To gain full marks you should refer to:

the enzyme and where the enzyme is produced
the products of digestion
any other chemicals involved.

ALL I KNOW IS THAT LIPASE IS PRODUCED AT THE PANCREAS AND SMALL INTESTNE AND BREAKIN DOWN INTO GLYCEROL AND FATTYACIDS. also THAT THE LIVER PRODUCES BILE WHICH SOMEHOW MULSIFIES FATS.. I NED HELP WITH MAKING A LOGICAL ANSWER SO I CAN REVISE FROM IT AND SEE WAT A 6 MARK ANSWER LOOKS IKE.. PS MY KNOWELEDGE MIGHT NOT EVEN LINK TO THE Q- THIS IS JUST WHAT MY RESPONSE WAS.. THANK YA FOR YA HELP X


There are different enzymes produced in different stages of digestion. At Secondary, you don't need to know about most of them, just the important ones. These include salivary and pancreatic amylases, which act on carbohydrates to break them into maltose, a dissacharide. There is also pepsin, made from pepsinogen in the stomach, which helps in protein digestion. You can learn more about them here:
http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa_pre_2011/enzymes/enzymes_and_digestion2.shtml

As far as other chemicals come in, it is mainly HCl in the stomach and some other hormones and substances in different part of the stomach.
Original post by artymaniac
PLEASE CAN SOMEONE PROVIDE ME WITH A LOGICAL EXPLANATION ANSWERING THE QUESTION.
Different parts of the human digestive system help to break down molecules of fat so that they can be absorbed into the body.

Describe how.
To gain full marks you should refer to:

the enzyme and where the enzyme is produced
the products of digestion
any other chemicals involved.

ALL I KNOW IS THAT LIPASE IS PRODUCED AT THE PANCREAS AND SMALL INTESTNE AND BREAKIN DOWN INTO GLYCEROL AND FATTYACIDS. also THAT THE LIVER PRODUCES BILE WHICH SOMEHOW MULSIFIES FATS.. I NED HELP WITH MAKING A LOGICAL ANSWER SO I CAN REVISE FROM IT AND SEE WAT A 6 MARK ANSWER LOOKS IKE.. PS MY KNOWELEDGE MIGHT NOT EVEN LINK TO THE Q- THIS IS JUST WHAT MY RESPONSE WAS.. THANK YA FOR YA HELP X


I answered this in a mock exam and this is basically what I wrote.

Molecules of fat and oil are broken down by the enzyme lipase, which produces fatty acids and glycerol. Lipase is produced by the pancreas and release into the small intestine, after the digestion of food in the stomach. As digestion in the stomach (via proteases) worked at a low pH 1, the pH level needs to be increased for lipase to function properly. Bile produced in the liver and stored in the gall bladder is released into the small intestines, where it neutralises the acid, thus raising the pH level. It also emulsifies the fat, breaking down large droplets into smaller droplets so that the lipase has more surface area to act on. The fatty acids and glycerol, along with other nutrients are absorbed in the small intestine via diffusion into the bloodstream.


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Reply 3
Original post by Dynamo123
There are different enzymes produced in different stages of digestion. At Secondary, you don't need to know about most of them, just the important ones. These include salivary and pancreatic amylases, which act on carbohydrates to break them into maltose, a dissacharide. There is also pepsin, made from pepsinogen in the stomach, which helps in protein digestion. You can learn more about them here:
http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa_pre_2011/enzymes/enzymes_and_digestion2.shtml

As far as other chemicals come in, it is mainly HCl in the stomach and some other hormones and substances in different part of the stomach.

Thank u very useful resource I have based a lot of my notes on it
Reply 4
Original post by kelly_kelly
I answered this in a mock exam and this is basically what I wrote.

Molecules of fat and oil are broken down by the enzyme lipase, which produces fatty acids and glycerol. Lipase is produced by the pancreas and release into the small intestine, after the digestion of food in the stomach. As digestion in the stomach (via proteases) worked at a low pH 1, the pH level needs to be increased for lipase to function properly. Bile produced in the liver and stored in the gall bladder is released into the small intestines, where it neutralises the acid, thus raising the pH level. It also emulsifies the fat, breaking down large droplets into smaller droplets so that the lipase has more surface area to act on. The fatty acids and glycerol, along with other nutrients are absorbed in the small intestine via diffusion into the bloodstream.


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Thank you so much this is really well answered and has helped me structure my response better thanks really appreciate it :-)
Original post by artymaniac
Thank you so much this is really well answered and has helped me structure my response better thanks really appreciate it :-)


No worries :wink:


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3b - Page 9/16Examples of biological points made in the response: mechanical breakdown in mouth / stomach fats fatty acids and / or glycerol by lipase (produced by) pancreas and small intestine fat digestion occurs in small intestine bile produced by liver neutralises acid from stomach produces alkaline conditions in intestine refs. to increased surface area related to emulsification or chewing products are small molecules / water-soluble products absorbed by small intestine
Hi v gd answers so far - just to add a little detail for full marks:-

Fats in diet are mostly triglycerides i.e. they have three molecules of fatty acid attached to the 3 -OH groups of glycerol (glycerol is an alcohol - alcohols have an -OH group in organic chemistry.

The bond between each fatty acid and -OH of glycerol is an ester bond:

C=O-R
|
O - (rest of glycerol)


STRUCTURE OF GLYCEROL

CH2OH
|
CHOH
|
CH2OH


When digestion of fats begins, one ester bond may be broken to leave one fatty acid and a diglyceride (2 fatty acids still attached to 2 -OH groups of glycerol, respectively) AND one FFA (free fatty acid).

Next step leaves: a monoglyceride and another FFA.

FINALLY glycerol and a total of 3 FFAs.

Hope this adds to your knowledge.

Thanks,
M (Specialist biology tutor)
Original post by macpatelgh
Hi v gd answers so far - just to add a little detail for full marks:-

Fats in diet are mostly triglycerides i.e. they have three molecules of fatty acid attached to the 3 -OH groups of glycerol (glycerol is an alcohol - alcohols have an -OH group in organic chemistry.

The bond between each fatty acid and -OH of glycerol is an ester bond:

C=O-R
|
O - (rest of glycerol)


STRUCTURE OF GLYCEROL

CH2OH
|
CHOH
|
CH2OH


When digestion of fats begins, one ester bond may be broken to leave one fatty acid and a diglyceride (2 fatty acids still attached to 2 -OH groups of glycerol, respectively) AND one FFA (free fatty acid).

Next step leaves: a monoglyceride and another FFA.

FINALLY glycerol and a total of 3 FFAs.

Hope this adds to your knowledge.

Thanks,
M (Specialist biology tutor)


Erm sir this thread is three years old :tongue:.
Thanks for the info bobby147 - I need to look higher up haha!
how many marks did you get for it?
Thank you
Different parts of the human digestive system help to break down molecules of fat so that they can be absorbed into the body. ... It also emulsifies the fat, breaking down large droplets into smaller droplets so that the lipase has more surface area to act on.

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