Chapter 8 ( Amino Acids , Proteins And Enzymes ) Flashcards
Hydrophobic amino acids ?
Phenylalanine Tyrosine Tryptophan Alanine Valine Leucine Isoleucine Proline Methionine
Hydrophilic amino acids ?
Aspartic acid Glutamic acid Lysine Arginine Histidine Serine Threonine Asparagine Cysteine
Sulfur containing amino acids ?
Cysteine
Methionine
Branched chain Amino acids that their metabolism are abnormal in maple syrup urine disease ?
Valine
Leucine
Isoleucine
Protein break down cellular sites ?
Lysosomes by lysosomal proteases which digest endocytosed proteins
Proteasomes ( large cytoplasmic complexes ) which digest older or abnormal proteins that covalently tagged with Ubiquitin for destruction
Essential amino acids ?
PVT TIM HALL Phenylalanine Valine Threonine Tryptophan Isoleucine Methionine Histidine Arginine ( only during positive nitrogen balance ) Leucine Lysine
Diet for PKU patient ?
Diet with restricted Phenylalanine and rich in Tyrosine
Negative nitrogen balance examples ?
Protein malnutrition Dietary deficiency of even 1 amino acid Starvation Uncontrolled diabetes Infection
Positive nitrogen balance examples ?
Growth
Pregnancy
Convalescence
Recovery from condition associated with negative nitrogen balance
Why Arginine is an essential amino acid during positive nitrogen balance conditions ?
As the urea cycle can’t make enough arginine needed for histone synthesis which in turn is needed for DNA synthesis
First order kinetics ?
The more substrate proportionally the more product is going to be made
0 order kinetics ?
Whatever increase in the substrate, the product is still the same as we reached the enzyme limiting capacity (Vmax)
Michaelis- Menten Equation ?
Describes how the rate of the reaction depends on the concentration of both the enzyme and the substrate which forma the product
Lineweaver-Burk equation ?
A reciprocal form of the Michaelis-Menten equation
Examples for competitive inhibitors ?
1- the Statin drugs ( lovastatin, simvastatin ) competitively inhibit HMG CoA reductase in cholesterol biosynthesis to control blood cholesterol
2- Methotrexate competitively inhibits dihydrofolate reductase depriving the cell of active folate needed for purine and deoxythymidine synthesis thus interfering with DNA replication during S phase
3- Oseltamivir which competitively inhibits influenza neuraminidase
