exam 3 week 2 biochem

3 things that add to amino acid pool in body

1. AA from dietary proteins

2. AA from protein turnover in body

3. Nonessential AA synthesis

3 ways amino acids are removed from pool in body

1. Synthesis of proteins

2. Synthesis of nitrogen containing compounds

3. Use of carbon skeleton for synthesis or energy

Pepsin

Protein digestion in stomach

CCK and secretin

From duodenum, stimulate pancreatic secretion in small intestine

What does enteropeptidase do

Cleaves trypsinogen into trypsin

Alpha-keto + NH3 = ?

Glutamate

Glutamate + NH3 = ?

Glutamine

2 important aminotransferases

AST and ALT

Pyruvate + NH3 = ?

Alanine

Where is ALT found

Muscles

Where is AST found

Liver

What does glutamate dehydrogenase do

Turn glutamate into alpha keto (removes NH3)

What does glutamine synthetase do, and where?

Turns glutamate to glutamine in all tissues

What does glutiminase do, and where?

Turns glutamine to glutamate in liver

Urea cycle overview

C and O from CO2 and amino from ammonia/ aspartate

Urea cycle step 1

Rate limiting, uses CPS-1 to turn CO2, ammonia, and ATP into carbomoyl phosphate

Step 2 of urea cycle

using ornithine transcarbomoylase, make citrulline

What is BUN

Blood levels of urea

What’s the affect of n-acetylglutamate on CPS-1

It’s activates it along with arginine

Urea cycle stimulated by what 2 things

1. High protein meal

2. Fasting and starvation (AA turnover)

Hyperammonemia

Urea producing ability is reduced, high ammonia depletes alpha keto and glutamate

Affect of hyperammonemia on the TCA cycle

It inhibits the TCA cycle

OTC deficiency

Increased carbomoyl phosphate and orotic acid

Hereditary orotic aciduria

Deficiency in UMP synthase, inc orotic acid, normal BUN + ammonia

Uridine monophosphate

Used to treat hereditary orotic aciduria

Age of onset for type 1 diabetes

Childhood or puberty (fast onset)

Age of onset for type 2 diabetes

After 35 (gradual symptoms)

Genetic component of type 1 diabetes

Moderate

Genetic component of type 2 diabetes

Very strong

Prevalence of type 1 and 2 diabetes

1- 10%

2- 90%

Defect in type 1 diabetes

Beta cells are destroyed, so no insulin

Defect of type 2 diabetes

Insulin resistance and beta cells produce inadequate insulin

Nutritional status of type 1 and 2 diabetes

1- undernourished

2- obesity

Ketosis in type 1 and type 2 diabetes

1- common → ketoacidosis

2- rare

Insulin levels in type 1 diabetes

Low to none

Insulin levels in type 2 diabetes

Early: high, later: low

How do you treat type 1 diabetes

Exogenous insulin

How do you treat type 2 diabetes

Weight loss, exercise, diet, Metformin, and sometimes insulin

What are the 3 Ps associated with type 1 diabetes onset

Polyuria (pee), polydipsia (thirsty), and polyphagia (hungry)

Which type of diabetes is an autoimmune disorder

Type 1

Explain how diabetes causes cataracts

Eyes take up glucose without the help of insulin, so hyperglycemia increases glucose uptake, which the eye converts to sorbitol

Describe insulin and glucose levels in type 2 diabetes

Insulin levels are higher to keep glucose levels the same