Flashcards
Amino Acid and Protein Metabolism
Cards in this deck (18)
- 1What are the 3 stages of the Translation phase?Iniation, Elongation, Termination.
- 2What is the purpose of Transamination and Deamination?Allows the formation of required AA's for prtotein synthesis or to Alpha-Ketoacids for entry into energy producing pathway.
- 3What is Transamination?Transamination is the transfer of Amino group from an unnecessary AA to make a required one. Results in a useful AA and a Alpha-Ketoacid.
- 4What is Deamination? And where does it occur?Deamination is the removal of an Amino Group to form an Alpha Ketoacid and Ammonia. Ammonia is toxic and needs to be removed which is achieved through conversion into urea and urinated out. Glutamate facilitates the removal. Deamination occurs in the liver.
- 5How can Alpha-Ketoacids be used for energy?They can be directly metabolised, The carbon chain (R-group) can be broken down to form TCA intermediates. It can also be broken down to form Pyruvate which is broken down to form Acetyl CoA whereby it can enter the TCA cycle for energy production.
- 6What cycle helps in ammonia removal?Glucose Alanine Cycle. This is a process whereby we remove a Ammonia molecule and receive a Glucose molecule in exchange. This helps maintain Glucose levels when demand is high.
- 7Protein Synthesis Steps:Gene-Expression ----> Transcription ---->Translation ----> Post Translational Processing
- 8What does Post Translational Processing Involve?After Polypeptide chainis released it needs additional processing before its in its functional location, in its active form, or in its functional shape (some fold naturally, others require help)
- 9How does the body know where the proteins functional location is?By a signalling protein which is at the start of the proteins polypeptide chain. Most Signalling Proteins are directed to the Sarcoplasmic Reticulum. If there is no signalling protein they are directed to the cytoplasm.
- 10What do Molecular Chaperones do?They bind to and fold the Polypeptide Chain to its final conformation.
- 11What do Scaffolding Proteins do?They transport proteins across the Mitochondrial Membrane
- 12Why do we break down proteins?Quality Control, Protein Turnover (Two types, Fast= Turned over every hour and Slow= Turned over every few days/weeks) and for Muscle Growth (Protein Degredation speeds up muscle growth through provision of AA for Protein Synthesis).
- 13Proteins for Energy?Proteins can be broken down into AA's which can be transaminated/deaminated into Alpha Ketoacids for energy production (broken down into Pyruvate) in the TCA Cycle or enter Gluconeogenesis for Glucose production. Proteins only account for 5% of energy and are spared by availability of CHO.
- 14What pathways break down proteins?Lysosomal (Proteins are engulfed by Lysosomes) Caspases (Cell Death) Calpain (Calcium activated breakdown of proteins) and the Ubiquitin-Proteasome Pathway.
- 15Which protein breakdown pathway is most used?Ubiquitin-Proteasome Pathway- It accounts for 80-90% of protein breakdown and maintains protein balance by killing bad proteins and keeping good proteins.
- 16What are the steps in the Ubiquitin-Proteasome Pathway?1) Ubiquitin recognizes the protein for degredation, binds to it and regulates quantity of protein.
2) E1 Activates Ubiquitin
3) Allows for attachment of Ubiquitin to protein, which allows chain of Ubiquitin to form on the protein. This chain signals for Proteasome to breakdown the protein to AA's. (Thus it is E3 that regulates specificity of protein breakdown) - 17Amino Acids (AA's) are the building blocks of proteins.AA's are formed of 3 components, an Amino Group, R Group (carbon chain) and Carboxyl Group
- 18How do we break down AA's?By Transamination or Deamination. Where the Amino Group is removed to form Alpha-Ketoacids.
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- Exercise Metabolism- Term 1 (Amino Acid and Protein Metabolism) Flashcards on Amino Acid and Protein Metabolism, created by Mark Arsenal on 15/04/2013.
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- Mark Arsenal · Apr 2013
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- Dec 9, 2016
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