W5-L1: Protein Flashcards
How is Protein digested and absorbed in the mouth?
Mechanical digestion occurs through chewing, no significant chemical digestion
How is Protein digested and absorbed in the Stomach?
- Hydrochloric acid denatures proteins, unfolding them into long polypeptide chains.
- Pepsin, begins breaking down these proteins into smaller polypeptides.
How is Protein digested and absorbed in the Small Intestine?
Enzymes from the pancreas (such as trypsin and chymotrypsin) and enzymes from the brush border of the small intestine further break down the polypeptide chains into free amino acids and smaller peptides.
How are proteins Absorbed?
Amino acids and small peptides are absorbed by enterocytes (intestinal cells) that line the small intestine through various transport mechanisms.
What happened to Amino Acids one they are absorbed?
Once absorbed, amino acids enter the bloodstream and are transported to the liver and other tissues for use in protein synthesis and other metabolic processes.
What are Amino Acids?
- Proteins are comprised of smaller units known as amino acids
- 20 Amino Acids - make structural and functional proteins
- Contain Nitrogen
- R-Side Chain –AA’s differ in size, shape, composition, electrical charge and pH
What are Nonessential Amino Acids?
Nonessential Amino Acids - 11
- Can be synthesized by the body from other amino acids
What are Essential Amino Acids?
Essential Amino Acids - 9
Cannot be made by body and must be obtained through diet.
What are Branched-Chain Amino Acids?
(BCAAs)
Subset of essential A.A’s critical for muscle health & metabolism.
- Leucine: Key for protein synthesis and muscle recovery via motor pathway
- Isoleucine: Supports energy regulation & immune function
- Valine: Important for muscle metabolism and tissue repair by supporting nitrogen balance
What are the 4 Fates of Amino Acids?
Amino acids can:
1. Undergo deamination: removal of the N (amine) group, resulting in the formation of urea, which is excreted in urine.
2. Have their carbon skeletons enter the Krebs cycle at various points, contributing to glucose, ketone, & lipid pools.
3. Be incorporated into body proteins or used to synthesize other nitrogen-containing compounds, such as nonessential amino acids.
4. Be oxidized for energy
What is the Nucleus’ Role in Protein Synthesis?
DNA contains genetic information necessary for protein synthesis.
How do Proteins get transcribed?
- Recognition of Need: The body recognizes need for specific proteins, and relevant gene(s) are “switched on”
- Transcription: DNA is unwound & transcribed to produce mRNA, which carries the “recipe” for a protein.
- Translation: The mRNA instructions are read by ribosomes to assemble amino acids into a polypeptide chain, ultimately forming a protein.
PROTEIN STRUCTURE LEVELS
What are proteins used for? (5)
What happens to Protein Synthesis if we have Insufficient Amounts of A.A?
All the amino acids required to build a specific protein must be present
Insufficient Amounts: An inadequate amount of any one amino acid may stop or slow the formation of a protein.
What happens to Protein Synthesis if we have Missing Nonessential Amino Acids?
If a nonessential amino acid is missing, the body can either synthesize it or obtain it from the amino acid pool in the liver via the bloodstream.
What happens to Protein Synthesis if we have Missing Essential Amino Acids?
If an essential amino acid is missing, the synthesis of the protein will halt, and the incomplete protein will be tagged for degradation.
The amino acids from this process will be recycled back into the amino acid pool.
What are examples of
PROTEIN RELATED COMPLICATIONS?
