Protein low in one EAA a protein in which that EAA is present in adequate

Protein low in one eaa a protein in which that eaa is

This preview shows page 30 - 32 out of 70 pages.

Protein low in one EAA + a protein in which that EAA is present in adequate amounts Protein Source PER Navy bean flour 1.56 Sesame flour 1.19 7/8 bean + 1/8 sesame 1.79 ¾ bean + ¼ sesame 2.26 ½ bean + ½ sesame 2.30 o Generally legumes limited in protein quality b/c they don't contain S-containing AAs o Sesame is deficient in Lys but has adequate S-containing AAs But when combined in the right proportions the EAA deficiencies cancel out and you end up with a higher quality overall protein source; this means that PER goes up (PER goes up for higher quality proteins) Reflective of AA composition - This combining can be done in humans (called complementary protein sources) but that's not an important issue in human protein nutrition b/c our needs are a lot lower than they are for growing animals. o Its more of an issue with kids growing up in vegetarian families b/c the needs for EAA and total protein in the growth stage are a lot higher in children than they are for adults. So children probably wouldn’t be able to meet their needs by consuming all beans or all sesame. But adults can easily meet their needs Therefore PER important for growth, but not important for adult maintenance
Image of page 30
SFLORES_3/17/2014 31 OTHER BIOLOGICAL METHODS THAT MEASURE PROTEIN QUALITY TRANSAMINASE LEVELS - Other biological methods exist to measure protein quality. For example, take a blood sample and measure transaminase enzyme in the blood - Transaminases in general are inside the cell (function to transfer N to the AA N carriers for the UC) and are involved in protein metabolism. o Poor quality proteins = high blood transaminase levels: the AAs from poor quality proteins are not utilized as efficiently which means you have more AAs that have to be detoxified/eliminated and oxidized, and the N transferred to waste N. Thus transaminase enzymes in the blood (first in tissues and then leak out into blood) This is a way to rank/ gauge the quality of proteins. High quality proteins have less transaminase enzymes because the AAs are utilized more efficiently, they are not readily oxidized vs. AAs from poor quality protein sources b/c they don't support protein synthesis - Transaminases can be of diagnostic value when you get sick o i.e.- when you have a heart attack, high [phosphokinase] are in muscle tissue. When the heart gets damaged, the cells die and release huge amounts of creatinephosphokinase. High levels of CPK is diagnostic of stress on the heart muscle or a heart attack UREA LEVELS - Poor quality proteins (PQPs) result in higher blood urea levels. Similar to the rationale for transaminase levels in the blood. o AAs from PQP don’t get utilized as wel l and they get more readily sent to the liver for synthesis of urea. So it temporarily blood urea levels PLASMA AA LEVELS - Theory behind measuring plasma AA levels: after you eat a meal, the AAs that are digested and absorbed are flooding into blood circulation and with the action of insulin, the AAs get
Image of page 31
Image of page 32

You've reached the end of your free preview.

Want to read all 70 pages?

  • Spring '14
  • Knutson,MitchellD
  • NRG

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors