Summary
Week 4 - summary proteins
- Course
- Institution
Summary of the course food components and health (HNE-25306). This summary is divided into multiple weeks, which were also given in the course.
[Show more]
Seller
Followjoepdonders
Reviews received
Content preview
Week 4 – ProteinsProteins are composed of chains of amino acids.
There are 20 different amino acids.
All amino acids have the same basic structure:
- Acid (carboxyl) group
- Amino group
- Side chain (R)
The side chain determines whether it is more hydrophilic or hydrophobic.
Essential amino acids: Amino acids that are needed in the diet because the body cannot make
these (there are 9).
The remaining 11 can be made from the 9 essential amino acids.
Linkages between carboxyl and amino group of different amino acids is called a peptide bond
leading to a dipeptide.
Raising young children on a vegan diet should be discouraged, but it is possible.
Digestion of dietary protein:
- No protein digestion in mouth
- Major protein digestion in stomach
- Major protein digestion in small intestine
- No digestion of protein in the colon
- A small amount of protein is lost in the feces
Amino acids, unlike proteins, can pass the intestine and enter into the bloodstream.
Stomach:
The acid environment causes proteins to unfold, allowing the enzyme pepsin easier to access.
Pepsin is produced by Chief cells lining the stomach. It is secreted as an inactive pro-enzyme
called pepsinogen.
Pepsinogen is activated by the acid environment resulting in self-cleavage to form pepsin.
Pepsin cleaves peptide bonds between specific amino acids:
Proteins pepsin polypeptides
Small intestine:
Two proteolytic enzymes called: trypsin and chymotrypsin produced by the pancreas. Also,
these enzymes are produced as inactive pro-enzymes which are activated once they reach the
small intestine.
They cleave the polypeptides at positions to release smaller peptides.
Polypeptides trypsin and chymotrypsin smaller peptides
Also the intestinal cells produce enzymes: aminopeptidases and carboxypeptidases. These
remove single amino acids from both ends, yielding single amino acids.
Smaller peptides amino/carboxypeptidase amino acids
The amino acids are absorbed into the portal circulation and are taken to the liver. Amino
acids will be used as building blocks for the synthesis of body proteins.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller joepdonders. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.21. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
52355 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now