Proteins Flashcards
Which amino acids are precursors for catecholamine?
Phe and Tyr
What is marasmus?
severe malnutrition caused by nutrient deficiencies, especially proteins and carbohydrates
Which amino acid does melatonin come from?
tryptophan
Which amino acid does nitric oxide come from?
arginine
Which amino acid is an important methyl donor?
Met
Which amino acid does niacin come from?
tryptophan
Which amino acids are purely ketogenic?
Leu and Lys
What is the chemical difference between pyruvate and alanine?
NH3 group
Name the positively and negatively charged amino acids.
positive: Lys, Arg, His
negative: Asp, Glu
Name the six polar uncharged amino acids.
Ser, Thr, Cys, Met, Asp, Gln
Which amino acids can disrupt normal secondary protein structure?
Pro, Gly
Which amino acid does dopamine come from?
tyrosine, which comes from phenylalanine
Which amino acids are both ketogenic and glucogenic?
Tyr, Ile, Phe, Trp
What are the ten essential amino acids?
Phe, Val, Thr, Trp, Ile, Met, His, Arg, Lys, Leu
Where in the cell does protein synthesis occur?
cytoplasm
Is the urea cycle reversible?
no
What two amino acids are acidic and negatively charged at body pH?
Asp, Glu
Which group of amino acids is associated with maple syrup disease?
branched chain amino acids (Val, Leu, Ile)
Which two amino acids are essential during growth, but not the rest of the time?
Arg, His (conditionally essential)
Which amino acids does heme come from?
porphyrin comes from glycine
NH4 + CO2, leads to ___, which enters the urea cycle where?
carbamoyl phosphate
enters at the conversion of ornithine to citrulline
Which reactions of the urea cycle happen in the mitochondria?
carbamoyl phosphate is formed and is added to ornithine to make citrulline
What amino acid is a precursor of GABA?
Glu
Disulfide bonds are created between adjacent molecules of which amino acid?
Cysteine
Which amino acid does norepinephrine and epinephrine come from?
tyrosine, via dopamine
What is an enzyme that hydrolyzes a peptide bond called?
proteolytic enzyme
List six nonpolar, aliphatic amino acids.
Gly, Ala, Val, Leu, Ile, Pro
Name the five steps of the urea cycle, starting with aspartate.
aspartate to arginosuccinate to arginine to ornithine to citrulline to arginosuccinate
What organs does the urea cycle occur in?
primarily in the liver, also kidney
Which amino acids can be glycosylated? What is the clinical significance?
Ser, Thr, and Lys
The lysine moiety of heme gets glycosylated in hyperglycemia (HbA1c)
What is the function of the urea cycle?
dispose of excess nitrogen
What are the three secondary structural conformations for proteins?
alpha helix, beta sheet, random coil
Which amino acid does thyroxine come from?
tyrosine, which comes from phenylalanine
Which amino acid can form serotonin and niacin?
Trp
What part of the cell does the urea cycle occur in?
1st 2 rxns: mitochondria
the rest in the cytoplasm
What are the immediate precursors of both molecules that make up urea (ammonium and aspartate)?
glutamate provides free ammonium and is also converted into aspartate
Name the three aromatic amino acids.
Phe, Tyr, Trp
Name the two purely ketogenic amino acids.
Leu, Lys
How many nitrogen are in urea?
2
What amino acid does creatinine come from?
Arg
Define negative nitrogen balance.
nitrogen loss exceeds incorporation
Which amino acid does NADP come from?
Trp, via niacin
What role does alanine play in nitrogen transport?
alanine carries nitrogen groups from muscles to liver
What is kwashiorkor?
protein malnutrition resulting in skin lesion, edema, liver malfunction (fatty change)
Which amino acid does urea come from?
Arg (NH3 is donated by glutamate)
Which amino acid is involved in the detoxification of ammonia?
Gln
Which amino acids are also important excitatory neurotransmitters?
Asp, Glu
Name the nine hydrophobic amino acids.
Gly, Ala, Val, Leu, Ile, Pro, Phe, Tyr, Trp
Which amino acid does histamine come from?
His
Which amino acid does serotonin come from?
Trp
Which amino acid is an important physiological (pH) buffer?
His
