Proteins Flashcards
What happens if the body lacks essential amino acids?
Body breaks down
What does it mean for a protein to be conditionally essential?
Demand exceeds what can be produced
True or false: functionally, all amino acids are essential
True
What are the 9 essential amino acids?
PVT TIM HALL
Gastrointestinal peptides are considered what?
Hormones or chemical neurotransmitters
What are the two types of bonds that peptides can undergo?
Peptide bonds or disulfide
What are the 5 stages of peptide synthesis?
- Amino acid activation
- Initiation of polypeptide
- Elongation
- termination
- folding/processes
What is the cause of cystinuria? Which AAs are involved?
Defect in cystine transporter for COAL (cystine, ornithin, R, Y)
What is Hartnup disease?
Deficiency of transporter for W
causing MR and a rash
True or false: protein turnover only occurs with muscle breakdown
False-always happening to maintain AA pool
Which are degraded faster: hormones or structural proteins?
Hormonal proteins
True or false: under normal conditions, Nitrogen = nitrogen out
True
When do proteins begin to be digested?
Stomach acid and proteases denatures
The majority of proteins are broken down where?
Small intestine
What activates pepsinogen to pepsin?
HCl
Where does pepsin work?
Stomach
What activates trypsinogen?
Endopeptidases in the intestines
What activates chymotrypsin?
Trypsin in the intestines
What activated procarboxypeptidase?
Trypsin
What is the enzyme in infants that works ion proteins in the mouth?
Rennin
What are the 8 common food allergies?
Milk Egg Shellfish Fish Tree nuts Peanuts Soybeans
What is the hypothesis for food allergies?
Intact proteins may be absorbed through leaky cell junctions in the small intestines
True or false: some AA are used in gluconeogenesis
True
What are the two AA that act as Nitrogen transporters?
Alanine and glutamine
What is the only AA that is completely oxidized in the muscle?
Leucine
Which AA rises in the blood during fasting?
Leucine
Leucine is used in the TCA how?
Converted to acetyl coA
The kidneys preferentially produces which AAs? (3)
R
H
S
The kidneys convert which two amino acids?
F to Y
G to S
True or false: essential AA are actively transported in neurons preferentially
True
What does the PDCAA score tell us?
a method of evaluating the protein quality based on both the amino acid requirements of humans and their ability to digest it
Which vitamin can really only be found in meat?
B12
What are the micronutrients needed for vegans? (6)
Ca B12 Fe Zn Vit D Omega 3
What are the relative rates of digestion for whey, meat, eggs?
Whey = fast Meat = intermediate Eggs = slow
Which has more protein digestibility: plant or meat protein?
Meat
What are the methods to measure protein metabolism?
Arteriovenous measure of AAs
End products
How do you measure protein turnover? (3)
Urea
Nonessential synthesis
Essential degradation
What is the estimated need for optimum nitrogen balance?
0.8 g/kg/day
What is the recommendation for nitrogen balance in the critically ill? Burns?
1.5g /kg / day
2g/kg for burns
Too much protein can result in what conditions (3)?
Pre-renal azotemia
Renal stones
Osteoporosis
Why is osteoporosis common in high protein diet?
Ca pulled out to balance negative charge of proteins
What happens to acid/base balance with increased protein?
more acidic
What is the effect of fruits/vegetables in acid/base balance?
Base producing
What happens if low grade metabolic acidosis is prolonged in high protein diets?
Conserving citrate and increases excretion of ammonium
True or false: metabolic acidosis from protein intake can lead to DM
true
After what time does the body convert to FAs for gluconeogenesis, and ketone bodies produced?
2 days
What is glutamine essential for?
Rapidly dividing cells
What is R essential for?
Immunomodulation
What is cystine essential for?
Anti-inflammatory properties
The cost of malnutrition is highest in what pts?
CA pts
Malnutrition comes from mostly which diseases?
Depression
COPD
CAD
What score on the malnutrition screening tool indicates a risk for malnutrition
2
True or false: decreased grip strength and fluid accumulation are indicative of malnutrition
True
How do you assess macronutrient status?
Fat
Muscle
Fluid
How do you assess micronutrient status?
Skin
Hair
Nails
Where are fat stores looked for to assess for malnutrition?
Eyes
Triceps
Ribs
What are the places to assess for fluid status in malnutrition?
Ankle edema
Sacral edema
Ascites
What is kwashiorkor?
Protein malnutrition with large abdominal
What is marasmus?
Severe starvation
True or false: not all peptides act via the endocrine pathway
True–autocrine, paracrine or endocrine are all possible routes
Which amino acids are absorbed faster: essential or nonessential?
Essential
Where does most protein digestion take place?
Duodenum
What is the protein involved in oncotic pressure maintenance?
Albumin
What are the proteins involved in clotting?
Fibrinogen, prothrombin
What is the minimum daily intake for proteins?
35 g/kg/day
What organ regulates the flow of amino acids?
Liver
Wounds that do not heal are indicative of micronutrient, or macronutrient deficiencies?
Micro
