Random-ass MBOD

Question 1

Name the 2 ketogenic AA’s

Answer 1

Leu, Lys

Question 2

Name the amino acids that are both keto and glycogenic?

Answer 2

Phe
Tyr
Trp
Ile

Question 3

The body doesn’t store AA’s. Where does it put them then?

Answer 3

Muscle protein

Question 4

When you are not ingesting food, the body still maintains a normal concentration of free AA’s in the blood. Where do these AA’s come from?

Answer 4

THe breakdown of muscle proteins.

Question 5

In order to use free AA’s, what must be done first? What problem results?

Answer 5

Deamination of free AA’s must occur before the body can use them. This creates a buildup of nitrogenous waste in the blood.

Question 6

What effect do glucocorticoids and thyroid hormones have on the breakdown of proteins>

Answer 6

They increase protein breakdown.

Question 7

REMEMBER: Insulin is the ANABOLIC hormone. Glucagon is CATABOLIC

Answer 7

Yeah.

Question 8

Name some proteins with high turnover rates:

Answer 8

Heme, muscle protein, digestive enzymes

Question 9

What AA is only essential during development and growth, but nonessential in adulthood?

Answer 9

Arginine

Question 10

What non-essential AA is derives from Phe?

Answer 10

Tyr

Question 11

WHat nonessential AA is derives from Met?

Answer 11

Cys

Question 12

How many essential AA’s are there? Name them.

Answer 12

10. PVT TIM HALL

Phe
Val
Thr
Trp
Ile
Met
His
Lys
Leu

Question 13

The majority of protein degradation that takes place in the body is of endogenous protein or dietary protein?

Answer 13

Endogenous.

Dietary protein is broken down and used for synths of new proteins.

Question 14

Dx this:

• muscle wasting
• decreased albumin levels
• distended abdomen
• child
• non-varied diet

Answer 14

Kwashiorkor- the absence of dietary essential amino acids

No ability to synthesize pancreatic enzymes and new intestinal cells.

Question 15

HOw would you treat Kwashiorkor?

Answer 15

Add Pancreatic protease to the diet

Question 16

In muscle, as proteins are broken down, they are trans/deaminated. What AA does the muscle export and what is its purpose?

Answer 16

NH3 from all the other AA’s in muscle are funneled to ALANINE for transport to the liver. Rids the muscle of excess nitrogenous waste.

Question 17

Name the 3 ways AA’s are transported.

Answer 17

Na+ dependent carriers
Facilitated Transporter
Gamma - glutamyl cycle

Question 18

What tissues use the gamma-glutamyl cycle for AA import?

Answer 18

Intestine and Kidney

Question 19

What substance is necessary for the gamma-glutamyl cycle to work?

Answer 19

GSH - Glutathione

Question 20

What 2 diseases of AA transport defects produce hyperaminoacidUREA?

Answer 20

Hartnup Disease (Neutral AA Urea)

Cystinuria

Question 21

What’s the main treatment for Hartnup Disease (Neutral Amino Acid Urea)

Answer 21

Niacin and HIGH protein diet

Question 22

What is the defect in Hartnup disease>

Answer 22

The intestine and kidney can’t absorb NEUTRAL and AROMATIC AA’s.

Remember: BOTH INTESTINE AND KIDNEYS INVOLVED

Question 23

What essential substance is deficient if a person has Hartnup disease?

Answer 23

No tryptophan (essential AA), so no NIACIN, which is necessary for Nad+/ NADH

Question 24

What is the defect involved with Cystinuria?

Answer 24

KIDNEY ONLY: Kidney can’t absorb cysteine and basic amino acids

Cystine and basic AA’s lost in the urine

Question 25

Do you have an AA deficiency in Cystinuria?

Answer 25

No. Cysteine and basic AA's are non-essential so no deficiency will be noted.

Question 26

What is the worst symptom of Cystinuria?

Answer 26

Due to increased amount of Cysteine in the urine, kidney stones form. Cysteine is INSOLUBLE in urine.

Question 27

What are the 2 substances that can cause kidney stones (that we have learned about)?

Answer 27

Cystine and Oxalate ?

Question 28

How do you treat Cystinuria?

Answer 28

Goal is to increase Cystine solubility. - Maintain large urine volume - Neutral or basic pH of urine - PENICILLAMINE (increases solubility of cystine)

Question 29

Do patients with Hartnup (Neutral AA Urea) or Cystinurea have hyperaminoacidemia?

Answer 29

No

Question 30

What are the 2 ways to remove alpha amino groups from an amino acid?

Answer 30

Transamination (most common) and deamination

Question 31

The a-ketoacid of Alanine is…...

Answer 31

Pyruvate

Question 32

The a-ketoacid of Aspartate is…...

Answer 32

Oxaloacetate

Question 33

What is the only amino acid that can enter the Urea cycle? (Hint: it donates an NH3 to urea)

Answer 33

Aspartate

Question 34

The a-ketoacid of glutamate is …..

Answer 34

a-ketoglutarate

Question 35

Name the 2 most important transaminases.

Answer 35

(ALT) Alanine Amino-transferase | (AST)Aspartate Amino-transferase

Question 36

Presence of both ALT and AST in serum is indicative of…..

Answer 36

Liver damage

Question 37

Where will you find the ALT enzyme?

Answer 37

IN the mitochondria of liver and cytosol of muscle

Question 38

WHere will you find the AST enzyme?

Answer 38

Only in the liver

Question 39

Aminotransferase enzymes require what cofactor?

Answer 39

PLP - Piroxidal 5" Phosphate

Question 40

Once the aminotransferases have created glutamate, what deaminase removes the NH3 from it?

Answer 40

Glutamate Dehydrogenase -> a-ketoglutarate + NH3 + NADPH

Question 41

What effect does Vitamin B deficiency have on transaminase reactions?

Answer 41

Inhibits. Need Vit B6 to synthesize PLP, which is necessary for transaminase activity.

Question 42

Some AA's are specifically deaminated by certain enzymes. Asn and Gln are examples. What are they deaminated by?

Answer 42

Asparaginase and Glutaminase to form Aspartate and Glutamate, which are then deaminated by ALT in liver, and glutamate dehydrogenase.

Question 43

Serine and Threonine are directly de-aminated by _____, which requires ______ to function.

Answer 43

Ser and The Dehydrogenase- PLP dependent!

Question 44

At physiological pH, what form is nitrogen in? (NH3, NH4+) Which form can cross cell membranes and into kidney tubules?

Answer 44

NH4+ is most common at physiological pH NH3 is able to be secreted

Question 45

How does ammonia regulate the pH of urine?

Answer 45

It is secreted into the kidney tubules as NH3. ONce in the urine, it binds free H+ atoms to form NH4+. This form can no longer cross the membrane

Question 46

What species within the era cycle carry the 2 nitrogens to donate to urea?

Answer 46

Citruline and Aspartate

Question 47

Carbamoyl Phosphate uses what enzyme?

Answer 47

CPS1 (carbamoyl -Pi synthase 1)

Question 48

CPS1 relies on what coenzyme?

Answer 48

NAG / NAG synthase

Question 49

Deficiency in NAG, NAGS, or CPS1 causes what?

Answer 49

Type 1 Hyperammonemia - Urea cycle shuts down

Question 50

How do you cure type 1 hyperammonemia?

Answer 50

Benzoate and Phenylacetate to rid the blood of Glu and Gln. The body is then forced to use the excess NH4+ for essential AA synthesis.

Question 51

How do you diagnose an OTC deficiency?

Answer 51

OTC is Ornithine transcarbamylase, which catalyzes the formation of citrulline. So no citruline, and OROTIC ACID is present.

Question 52

What other pathway is orotic acid involved in?

Answer 52

Pyrimidine synthesis. So turn urea cycle off, turn on pyrimidine synthesis.

Question 53

How does excess urea affect the brain?

Answer 53

The body stores excess NH4+ as Glu and Gln. The order goes a-ketoglutarate to glutamate, to glutamine. Eventually, all the glutamate is used up and a-ketoglutarate is used to form more. This depletes the TCA cycle= cell death. Also, no more glutamate = no more GABA Increased osmotic pressure = edema

Question 54

Mutations in both CPS1 and OTC cause…..

Answer 54

Hyperammonemia, which can be treated with benzoate and phenyl acetate.

Question 55

Arginosuccinase deficiency can be partially bypassed by:

Answer 55

- Restricting protein intake | - ARGININE SUPPLEMENTS