Biochemistry Lecture 15-16- Amino Acids/Urea Cycle

Protein digestion

this starts in the stomach with physical grinding and pepsin, then moving to the small intestine and large intestine to digest even more, eventually allowing microbiomes to process these, where they eventually are transferred to the liver

Zymogen

these are inactive precursors of digestive enzymes

-ogen

zymogens are usually just the enzyme name but with this suffix at the end

Low pH

Pepsinogen is activated (to pepsin) by the autocatalytic cleavage at what condition?

Enteropeptidase, itself

Trypsinogen is secreted by the pancreas and is activated by __________________, then _________

Trypsin

Chymotrypsinogen is secreted by the pancreas, and activated by ___________

Trypsin

Pro-carboxypeptidases A and B are secreted by the pancreas, and activated by _____________

Pancreatic tryspin inhibitor

this prevents trypsin activity in the pancreas by inhibiting any activated trypsin if its in the pancreas

Digest ourselves

If we didn't have pancreatic trypsin inhibitor, we would ____________ ___________________

Reduced

The nonpolar amino acids are a really good source of energy, because all of the carbons are fully _________________

make proteins

Amino acids are a really good source of energy, however we don't rely of them solely for energy because we need the amino acids to __________ ______________ in our own body

Toxic

When catabolising amino acids, we need to have a series of transaminations because free ammonia is ___________

Transaminase

these type of enzymes are enzymes that transfer amino groups

Urea

Most of the waste nitrogen in humans is eliminated as _______

Glutamine, Glutamate

These two transport amino acids are used as amino group carriers

Pyridoxal phosphate

The major coenzyme form of vitamin B6 that functions in more than 100 enzymatic reactions, many of which involve amino acid metabolism.

Glutamine, Alanine

These two amino acids are carriers of ammonia from metabolically active tissues to the liver

Glucose-Alanine cycle

Pyruvate can be converted into Alanine via alanine aminotransferase (PLP). Adds a NH4+ group from glutamate to pyruvate. Alanine can travel to the liver and be reconverted back into pyruvate needed for gluconeogenesis.

alpha-ketoglutarate, Glutamine

2 Glutamate in the muscle can be converted into 1 ______-_________________ and 1 _________________, which allows it then to be transported to the liver to be turned into urea

Mitochondria, alpha-ketoglutarate

When glutamate reaches the liver, it can go into the ____________________(what organelle?), and release the amino group as ammonia, converting the glutamate into ____-________________, which can be used in the CAC or gluconeogenesis

Upregulated

If there are high amounts of ADP, then oxidative deamination is _____________(upregulated/deregulated)

Deregulated

If there are high amounts of GTP, then oxidative deamination is ________________(upregulated/deregulated)

ALT

this enzyme helps in the liver to transfer an amino group from alanine to alpha-ketoglutarate to make pyruvate and glutamate

AST

this enzyme in the liver helps convert oxaloacetate and glutamte into aspartate and alpha-ketoglutarate

Liver failure

if there are high amounts of ALT and AST in the bloodstream, it is a strong indicator of __________ _____________

Urea

this is a highly oxidized waste product, which has two amide groups

Mitochondria

Which organelle can free ammonia be added to the Urea Cycle?

Cytosol

Where can aspartate be added to the urea Cycle?

Urea cycle

process that converts potentially toxic nitrogen waste into urea that can be eliminated through the kidneys

Glutamate

most of the ammonia from the urea cycle comes from ________________

Mitochondria

The urea cycle "starts" in the ______________________

Carbamoyl phosphate, ATP, mitochondria

Before the urea cycle starts, we have to have the formation of ____________ ____________ using the components of bicarbonate, ammonia, and ________ inside the __________________

Ornithine, citrulline

the "first" step of the urea cycle starts with carbamoyl phosphate reacting with ________________ to form _________________

Mitochondria

Carbamoyl phosphate + Ornithine -> Citrulline takes place in what organelle?

Cytosol

Citrulline then leaves the mitochondria into the _____________, which is where the rest of the Urea cycle takes place

ATP, aspartate, arginosuccinate

Citrulline (in the cytosol) reacts with _____ to form Citrullyl-AMP, which then reacts with _______________ to form ____________________, giving off AMP as a biproduct

Arginosuccinase, arginine, fumarate

After arginosuccinate is formed, the enzyme _______________________ cleaves it to form ________________ and ________________

Malate

When formed, arginine continues in the urea cycle, while fumarate can be converted into _____________, and join the CAC

arginase, urea, ornithine

After arginine is formed, the enzyme ____________ cleaves arginine and forms _______ and ______________, which can be transported back to the mitochondria to start over the cycle, but the first product is the main waste product we want

Krebs bicycle

relationship between the urea cycle and the citric acid cycle, because many of the products overlap and enzymes are both present in cytosol and the mitochondria

2

The formation of carbamoyl phosphate requires how many ATP?

1

Arginosuccinate production requires how many ATP?

Increase

High protein diets or starvation __________________(increase/decrease) production of urea

Increase

If there is long term increased urea production, the amount of enzymes in the urea cycle will ______________

Carbamoyl phosphate synthetase 1

The short term effect of regulating the Urea cycle is the regulation of which enzyme?

Increase

At high cocnetrations of arginine, glutamate, or acetyl CoA, the production of carbamoyl phosphate will ________________

Remove protein

Defective urea production results in liver failure, and the main treatment for this is to ___________ _______________ from your diet

Destroy

Amino Acid deficiency is quite bad because then the body will have to ______________ protein in the body to make new amino acids

Positive nitrogen balance

state in which the body retains more nitrogen than it loses, most offen occurs when someone is growing

Negative nitrogen balance

Condition occurring when the body excretes more nitrogen than it takes in, most common when the body has insufficient protein fromdiet

Essential

If the body is deficient in a single ______________ amino acid, then it will think it's in a negative nitrogen balance

Leucine and Lysine

These two amino acids are purely ketogenic

Isoleucine, Threonine, Phenylalanine, Tyrosine, Tryptophan

These 5 amino acids are both ketogenic and glucogenic

Alanine, Cysteine, Glycine, Serine, Arginine, Glutamine, Glutamate, Histidine, proline, Methionine, Valine, Aspartate, and Asparagine

Which amino acids are purely glucogenic

BCKADH

the branched chain amino acids (Valine/Isoleucine, Leucine) are metabolised by this enzyme after being converted into alpha-keto acids into Acyl-CoA derivatives

Maple Syrup Urine Disease

is caused by a defect in alpha keto acid dehydrogenase, leading to an inability to degrade branched amino acids (isoleucine, leucine, and valine)

Vitamin B12 Deficiency

this causes red glazed tongue, mouth ulcers, and can have fatal consequences like loss of balance, dementia, etc.

Folate

this forms tetrahydrofolate and transfers 1 ccarbon in many different oxidation states, which can be used in many metabolic reactions

Slow

If THF (folate) forms are deficient, nucleotide synthesis _________, which in effect causes DNA synthesis to ________, which causes cell division to __________

Folate, methyl

If there is no vitamin B12, this results in the functional deficiency of _____________ by effect, because all of the folate becomes trapped as ______________-THF