Exam 4 Misc Flashcards
Two backup systems in the liver to deal with Ammonia.
Periportal and Perivenous both located in the acinus
Periportal system
glutaminase releases NH3 from glutamine to make urea via the cycle
glutamate dehydrogenase releases NH3 from glutamate to create a-ketoglutarate
Perivenous system
glutamine synthetase scavenges excess NH3 to make glutamate and a-ketoglutate which are taken to the kidneys for deamination
Transamination
Amino Acid 1 + Keto Acid 2 –> Amino Acid 2 + Keto Acid 1
Deamination
Amino acid –> keto acid + NH3 (via dehydratase)
General Catabolic Site for amino acids
Most in liver and kidney with the branched chains in the muscle
Cause of Maple Syrup Urine Disease
Deficiency in the Branched Chain a-keto acid Dehydrogenase Complex
Cause of Phenylketonuria
Deficiency in the enzyme Phenylalanine Hydroxylase. Without it, Phenylalanine can’t be broken down to Tyrosine. It builds up and becomes phenylpyruvate / phenylketone
Catecholamines are derived from which amino acid?
Tyrosine
Which amino acid makes niacin and where?
Tryptophan in the liver
Which amino acid makes taurine?
Cysteine
Which amino acid makes Cysteine?
Methionine
Which amino acid is considered semi-essential and why?
Cysteine because infants and those with certain metabolic diseases or malabsorbtion syndrome are unable to get it
Which Amino Acids do not undergo transamination?
Lysine and Threonine
What happens physically when you do not consume enough essential amino acids?
Muscle degradation (body breaks down muscle to get protein), decreased immune response, weakness, fatigue, and changes to the texture of your skin and hair
What happens mentally when you do not consume enough essential amino acids?
Lysine has an effect on serotonin and stress.
Which tissues can use ketone bodies?
The same tissues that can use fatty acids (heart, brain and not liver)
Which amino acids are important to transfer amino acids from the muscle to the liver?
Glutamine and Alanine
Creatine use in exercise vs rest
During exercise phosphocreatine provides a way to replenish ATP (substrate level phosphorylation) while at rest the phosphocreatine is degraded to creatine and excreted.
Rate limiting enzyme of the urea cycle
Carbamoyl Phosphate Synthetase
6 Primary functions of proteins
Hormones, enzymes, antibodies, Transportation and storage or molecules, energy, repair
Insulin Function
GI hormones amplify pancreatic response to glucose. Stimulates glycolysis, glycogenesis, lipogenesis, protein synthesis. Affects glucose uptake in muscle and liver.
Glucagon
Activates liver lipases and glycogenolysis
Catecholamines
Increase blood glucose by decreasing glucose uptake of muscles. Epi / Norepi
Glucocorticouds
Important for stimulating gluconeogenesis. Cause degradation to make amino acids available. Adrenal cortex
Phases of fed / fasting
Fed / Post Absorption: Glycogenolysis
Fasting: Gluconeogenesis
Starvation: Gluconeogenesis / Ketosis
When can ketones not be made?
When insulin is high
Which amino acids can become glucose?
Ala, Gly, Cys, Ser. Must first be able to be converted to pyruvic acid
Which amino acids can become lipids?
Ile, Leu, Trp, Lys, Phe, Tyr. Must first be able to be converted to Acetyl CoA
