Protein Metabolism Flashcards
Define non-essential amino acids
Amino acids that are produced by the body therefore they aren’t essential.
Define essential amino acids
Amino acids that cannot be produced by the body and are obtained through diet.
Make flash cards based on slide 2
Could not make while at work w/o notes
What are the two groups important in forming a peptide bond for an amino acid?
NH2 group & COOH group to form a peptide bond. Assume the R group will attach eventually.
List the essential amino acids
- Histidine
- Isoleucine
- Leucine
4.Lysine
5.Methionine - Phenylalanine
7.Threonine
8.Tryptophan
9.Valine
What are the two ionizable groups on an amino acid?
The Nitrogen group (NH3) and COOH group
If the pH is lower than the isoelectric point (pI) which group on the amino acid will have a charge?
The NH3 group. It’ll be a positive charge.
At neutral pH what group on the amino acid will have a charge?
Both
When pH is higher than the isoelectric point which group (on amino acid) will have a charge?
The COOH group. It’ll be a negative charge.
Define the isoelectric point.
pH at which overall net charge is neutral.
What are the different kinds of protein made in protein synthesis?
- Plasma proteins
- Intracellular proteins
- Structural Proteins
How much energy is expended in amino acid metabolism?
12 - 20% of total energy supply
Amino acids are used to create what non protein nitrogenous compounds?
- Purine
- Pyrimidine
- Porphyrins
- Creatine
- Urea
- Histidine
- Thyroxine
- Epi
- Coenzyme NAD+
Cysteine, glycine, serine, alanine, and threonine can all be converted to what chemical before entering the TCA cycle?
Pyruvate then Acetyl - CoA
Tryptophan and lysine are converted to what chemical before entering the TCA cycle?
Alpha - Ketoadipate
Phenylalanine, Leucine and tyrosine can be converted into what chemical to eventually enter the TCA cycle
Acetoacetate, then acetoacetyl - CoA and finally Acetyl - CoA
Tyrosine can be converted to not just acetoacetate but also what other two chemicals to contribute to the TCA cycle?
Fumarate or Oxaloacetate
Asparagine and aspartate can be converted to what two materials to contribute to the TCA cycle?
Oxaloacetate or Fumarate
Arginine, Proline, Histidine, Glutamate, and Glutamine can be converted to what chemical to be funnel into the TCA cycle?
Alpha - Ketoglutarate
Isoleucine can be converted to what two chemicals to contribute to the TCA cycle?
Acetyl - CoA or Succinyl CoA
Methionine, Isoleucine, and Valine can be converted to what chemical
Succinyl CoA
The enzyme methylmalonyl CoA mutase requires ______ to convert L-Methylmalonyl - CoA to succinyl-CoA.
Vitamin B12
What is the name of the disorder for inborn error of phenylalanine metabolism?
PKU, Phenylketonuria
What enzyme is defective in PKU?
Phenylalanine hydroxylase. The defective enzyme prevents conversion of phenylalanine to tyrosine.
In PKU the accumulation of phenylalanine and/or phenylpyruvic acid leads to…
Severe metabolic acidosis & neurological problems however it can be controlled by monitoring diet.
Describe tyrosinemia
A disorder that leads to the accumulation of tyrosine because of the absence/defective enzyme that catabolize tyrosine in liver.
What enzyme is effected in Type 1 Tyrosinemia?
Fumarylacetoactetate hydrolase
What are some symptoms for a patient with type 1 tyrosinemia.
- Failure to thrive, jaudice, cabbage like odor, and nose bleeds
- Liver & kidney failure, neuropathy, and hepatic tumors
What enzyme is effected in Type 2 tyrosinemia?
Deficiency of tyrosine aminotransferase
What are some symptoms for a patient with type 2 tyrosinemia.
Excessive tearing, photophobia, eye pain, lesions, and mental retardation.
What enzyme is effected in Type 3 tyrosinemia?
Deficiency of 4-hydroxyphenylpyruvate dioxygenase
What are some symptoms for a patient with type 3 tyrosinemia?
Mild retardation, seizures, and intermittent ataxia (slurred speech, stumbling, falling, and incoordination in other words degeneration of the nervous system)
What are other names for alkaptonuria?
Black urine disease or black bone disease
What enzyme is defective in alkaptonuria?
Homogentisate oxidase
What are some long term problems patients with alkaptonuria run into?
Kidney, prostate calculi, and heart problems
If homogenisate oxidase is defective what will happen in the body?
- Increased homogentisic acid (HGA), its an intermediate breakdown product
- HGA is deposited in connective tissue, cartilage, and skin leading to darkening of skin, urine and arthritis
- Urine turns to black when exposed to air
- Patient may develop kidney, prostate calculi, and heart problems.
Maple syrup urine disease has what defective enzyme?
Alpha ketoacid dehydrogenase
The defective alpha ketoacid dehydrogenase leads to what symptoms in the body?
- Poor feeding, vomiting, lethargy, seizures, and developmental delays
- Urine smells like maple syrup
What amino acids cannot be broken down in the body with maple syrup urine disease?
Valine, Isoleucine, and Leucine
What enzyme is defective in isovaleric acidemia?
Isovaleryl-CoA dehydrogenase (IVD) enzyme
What enzyme is unable to be broken down
What are the two amino acids you cannot use for gluconeogenesis?
Leucine and lysine
What are left over amino acids turned into ?
Ammonia then goes through the urea cycle
What is the rate limiting enzyme in the urea cycle?
Carbamoyl phosphate synthetase
Where is urea reabsorbed in the nephron?
Distal tubule
How much urea is excreted?
60%
What is used to transport citrulline out and ornithine in the mitochondria?
A symporter
Define zwitterion
Amino acid with an equal number of opposing charge
What pH is there ionizable groups?
7.4
A cation has a pH ______ pI.
less than
A anion has a pH ____ pI
greater than
What organ is involved in plasma protein synthesis and secretion?
Liver with albumin being the most abundant protein.
What makes intracellular proteins?
Cytoplasmic free ribosomes
List non protein nitrogen compound synthesis
Purine, Pyrimidine, porphyrins, creatine, Urea, Hisitidine, Thyroxine, Epi, Coenzyme NAD+
Energy substrates such as carbs, fat, and protein are what percentage of total energy supply?
12% - 20%
What are the amino acids broken down into pyruvate then acetyl-coa?
Threonine, glycine, serine, cysteine, and alanine.
What are the amino acids used to make alpha-ketoadipate, acetoacetate, acetoacetyl-coa and then acetyl-coa?
Lysine, tryptophan, phenylalanine, tyrosine, and leucine
What are the amino acids used to make alpha-ketoglutarate?
Arginine, proline, histidine, glutamine, and glutamate
What are the amino acids used to make succinyl CoA?
Methionine, Isoleucine, and valine
What is the enzyme used to convert L-methylmalonyl-CoA?
Methylmalonyl CoA mutase. It is a B12 dependent enzyme