final review

Question 1

1. The two important roles serum proteins play in the body

Answer 1

a. Play an important role in water distribution and acid base balance between tissues and blood

Question 2

2. How are serum proteins grouped

Answer 2

a. Albumin and globulins

Question 3

3. The 4 functions of proteins

Answer 3

a. Structural functions (collagen and elastin)
b. Regulatory functions (hormones and enzymes)
c. Specific carrier proteins (transport blood components like bilirubin, calcium, lipids, metals, oxygen, steroids, thyroid hormones, and vitamins)
d. Mediators of immune response (antibodies)

Question 4

4. Amount of total protein in adult humans and the tissue with the greatest concentration of protein

Answer 4

a. Adult human body contains 10-13 kg of protein (70 kg reference man)
b. Muscle has the greatest concentration at 22 g/kg

Question 5

5. Body cell mass definition

Answer 5

a. The skeletal muscle protein (somatic protein) and the visceral protein together compose the metabolically available protein known as body cell mass
b. *Metabolically active protein in body

Question 6

6. Functions of serum proteins

Answer 6

a. Maintenance of normal distribution of water between tissues
b. Acid-base balance of blood
c. Transport
d. Immunity
e. **do not have a structural component

Question 7

7. Protein quality

Answer 7

a. Plant and animal proteins differ as a food source
b. Animal proteins (except gelatin) supply a full complement of 20 amino acids including essential amino acids.
c. Plant protein amino acids (incomplete proteins)
d. Soy protein has a high amino acid score for a plant product
i. Complete protein-only plant that is a comp. protein

Question 8

8. Conditions in which serum total protein increase

Answer 8

a. Increases
i. During dehydration (vomiting or diarrhea)
ii. During multiple myeloma (presence of myeloma proteins)-a malignant neoplasma of bone marrow

Question 9

9. Factors affecting serum protein concentrations

Answer 9

a. Inadequate intake
i. Low dietary intake
ii. Anorexia
iii. Unbalanced diet
iv. Hypocaloric intravenous infusions
b. Altered metabolism
i. Trauma
ii. Stress
iii. Sepsis
iv. hypoxia

Question 10

10. How is somatic protein status assessed (know all 3 methods)

Answer 10

a. Urinary creatine excretion (muscle)
b. Creatine/height ratio (ratio of BUN:creatine)
c. 3-methylhistidine excretion (derived from myosin and actin)

Question 11

11. How is visceral protein status assessed

Answer 11

a. Total serum protein (TP)
b. Serum albumin
c. Serum transferrin
d. Prealbumin (tranthyretin)
e. C-reactive protein

Question 12

12. When is total protein significantly depleted

Answer 12

a. Total serum protein concentration is maintained within normal limits despite restricted protein intake
b. TP is only significantly depleted when clinical signs and/or protein malnutrition are present

Question 13

13. What are two negative acute-phase responders

Answer 13

a. Albumin method-negative acute-phase responder. Long half-life of ~20 days. Used to asses chronic malnutrition and muscle loss
b. Prealbumin method-negative acute-phase responder. Short half life of ~2 days. Used to asses acute changes
c. So…. Albumin and prealbumin are the two neg. acute phase responders

Question 14

14. What is the half life of albumin and pre albumin

Answer 14

a. Albumin ~ 20 days

b. Prealbumin ~ 2 days

Question 15

a. PEM

Answer 15

i. Deficiency of both protein and energy

Question 16

b. Marasmus

Answer 16

i. Starvation (absolute deprivation of food) results in depletion of skeletal muscle. One extreme of PEM. Albumin shifts intravascularly in marasmus

Question 17

c. Kwashiorkor

Answer 17

i. Low protein intake in relation to energy intake. Results in depletion of visceral protein pool, and edema. Other extreme of PEM. Albumin shifts extravascular in Kwashiorkor

Question 18

16. Serum ranges for albumin and pre albumin – normal range

Answer 18

a. Albumin – 3.5-5.0 g/dL

b. Prealbumin – 19-43 mg/dL

Question 19

17. All information under “introduction”, Lab 8

Answer 19

a. Protein catabolism results in the release of nitrogen in the form of ammonia and other nitrogenous compounds
b. Ammonia must be rapidly converted to a less toxic form to facilitate excretion and maintenance of homeostasis
c. Ammonia is converted to urea through the urea cycle in the liver
d. The rate of production of urea is increased after an intake of a high protein diet or by increased protein catabolism due to starvation or tissue injury.
e. The presence of liver disease will decrease the capacity of the liver to convert ammonia to urea, resulting of an increase in blood ammonia concentration
f. Plasma and urine ammonia should be determined separately if high levels are expected
g. Urea in the blood is referred to as blood urea nitrogen (BUN)
h. Urea in the urine is referred to as urine urea nitrogen (UUN)

Question 20

18. What is UUN affected by

Answer 20

a. Protein intake
b. Kidney function (used to evaluate renal function)
c. Urine volume

Question 21

19. Know everything about the nitrogen balance equation

Answer 21

a. Balance= (protein intake (g)/6.25) – (urinary urea N2 (g)) +4 g
b. Indicates the net change in the total body protein mass
c. In this equation, nitrogen intake is estimated from the protein intake, assuming that protein contains 16% nitrogen in a mixed diet.
d. If parenteral solutions contain free amino acids are used, specific conversion factors should be used to calculate their nitrogen content exactly
e. The constant (4g) in the equation above represents two correction factors:
i. 2 g for dermal and fecal losses of nitrogen, which occur but are not measured
ii. 2 g for the non-urea nitrogen components of the urine (e.g. ammonia, uric acid, and creatine

Question 22

20. Why does an estimate of the change in nitrogen balance require 3 consecutive, 24 hour urine collections

Answer 22

a. An estimate of the change in nitrogen balance, rather than a single measurement, is preferred to monitor the effectiveness of nutritional therapy
b. Requires three consecutive, 24-hour urine collections.
i. Especially for hospital patients
ii. The intra-subjective variation for urinary nitrogen excretion can be large
iii. Care must be taken to avoid spills, discards, or inadvertent omissions of urine during collection, because these lead to a positive effort in the nitrogen balance
iv. Best practice is to avoid any analysis of improperly collected samples and start over

Question 23

21. “in” nitrogen balance

Answer 23

in” nitrogen balance

i. definition: intakes are adequate to replace the endogenous nitrogen losses and for the growth of the hair and nails
ii. healthy adults with adequate energy and nutrient intakes should be “in” nitrogen balance

Question 24

22. All factors contributing to negative nitrogen balance

Answer 24

a. Inadequate protein and/or energy intakes
b. Imbalance in essential amino acid and non-essential amino acid ratio: EAA/NEAA
c. Conditions of accelerated protein catabolism:
i. Trauma
ii. Infection
iii. Sepsis
iv. Burns
v. Excessive losses of nitrogen arising from fistulas or excessive diarrhea

Question 25

23. Conditions in which the estimated nitrogen balance equation is not appropriate

Answer 25

a. Malabsorption i. When fecal nitrogen losses may be elevated ii. Making the correction factor of two grams for dermal and fecal losses of nitrogen inappropriate b. During severe energy restriction or starvation i. When the production of renal ammonia is increased to such an extent that the non-urea nitrogen correction factor of 2 grams is inadequate c. When protein intakes are low i. Urinary urea nitrogen is no longer a valid index of total urinary nitrogen excretion because it accounts for a decreasing percentage of total urinary nitrogen excretion: 61% to 70% compared to more than 80% to 90% on a normal mixed diet d. During increased excretion of urea (ureagenesis) i. When diets are based on proteins of low biological value ii. When parenteral or enteral solutions contacting certain amino acids (e.g. arginine and glutamine) are administered

Question 26

24. Daily urea urinary excretion values; plasma/serum values of urea; what happens to urea excretion in urine when protein intake increases

Answer 26

a. Daily urea urinary excretion: 5-20 g/d b. Plasma/ serum values of urea: 8-23 g/dL i. Panic value: >37 mg/dL

Question 27

25. Definition of anthropometrics

Answer 27

a. to evaluate the progress of growth in pregnant women, infants, children, and adolescents b. to detect under nutrition and over nutrition in all age groups c. to measure changes in body composition over time

Question 28

26. 3 main functions of anthropometrics

Answer 28

a. to evaluate the progress of growth in pregnant women, infants, children, and adolescents b. to detect under nutrition and over nutrition in all age groups c. to measure changes in body composition over time

Question 29

27. All information under body composition

Answer 29

a. Body composition is used in reference to the fat and nonfat components of the human body the fat component is usually referred to as fat mass (FM) or percent body fat (%BF) b. The nonfat component is referred to as lean body mass (LBM) c. There are several different procedures whereby body composition can be determined d. The most common techniques are: i. Hydrostatic or underwater weighing ii. Measurement of body volume iii. Skinfold thickness iv. Circumference measurements

Question 30

28. BMI definition and formula

Answer 30

a. BMI is an index of a person’s weight in relation to height b. BMI = kilograms/ meters2 c. BMI = (pounds x 703/ inches2

Question 31

29. Waist-to-hip ratio definition and formula

Answer 31

a. The waist to hip ratio is a valuable indicator of body fat distribution b. The ratio is determined by dividing the waist circumference in inches by the hip cirvumference in inches c. Waistline (inches)/ hip (inches) d. Women with 0.08 or greater, and men with a ratio of 0.95 or greater are at high risk of obesity-related health problem

Question 32

30. 2 methods used to determine % body fat

Answer 32

a. skin fold measurements | b. body fat analyzer

Question 33

31. How to calculate ideal body weight using the Hamwi equation for males and females

Answer 33

a. Males: 106 for 5 ft i. Add 6lbs for each inch over 5 ft b. Females: i. 100 lbs for 5 ft ii. add 5 lbs for each inch over 5 ft

Question 34

32. How to calculate % IBW

Answer 34

a. % IBW = (current BW/ ideal BW) x 100

Question 35

33. All information in Table 2: Classification of Body Composition based on BMI (NIH)

Answer 35

Classification BMI, kg/m2 Risk Underweight 25 Increased risk of disease Obese (classI) >30 Further risk of disease Obese class II >35 Higher risk of disease Extremely (morbidly ) obese class III >40 Highest risk of disease

Question 36

34. All info. in Table 3: Waist to hip ratio

Answer 36

Male Female Risk | >0.95 >0.80 Greater risk: obesity-related condiditons

Question 37

35. All info. in Table 4: Waist circumference

Answer 37

Male Female Risk >40 (122 cm) >35 (88 cm) Independent risk factor for disease when out of proportion to total body fat; may not be as useful for those 35 Apple shape or android obesity weight around the trunk; fat placed in abdominal (truncal) reigion; visceral fat Greater risk: obesity-related conditions like cardiovascular, type 2 diabetes and some cancers Pear shape or gynoid obesity; weight around the hips Metabolic risks are lower

Question 38

36. Table 8: Weight as an indicator of nutrition status – know >120 % is obese and <70% is severely undernourished

Answer 38

% ideal body weight % usual body weight Nutritional status >120 - Obese <75 Severely undernourished

Question 39

“positive” nitrogen balance

Answer 39

“positive” nitrogen balance i. Nitrogen intake exceeds nitrogen output ii. Occurs during growth, late pregnancy, athletic training, and recovery from illness

Question 40

“negative” nitrogen balance

Answer 40

c. “Negative” nitrogen balance i. Nitrogen output exceeds nitrogen intake ii. A negative nitrogen balance 1 g/d is equivalent to a reduction in total body protein of 6.25 g/day iii. If the negative balance persist, the resultant protein depletion may have adverse effect on all organ system

Question 41

Conditions in which serum total protein decrease

Answer 41

b. Decreases i. During nephrotic syndrome (albumin lost in damages kidneys). When albumin is lost from blood there is a movement of water from circulation to intestinal fluid and tissues, resulting in edema. Protein in the urine is a key indicator of renal disorder ii. During a low protein intake or malabsorption iii. During starvation iv. During severe hemorrhage v. As a result of liver disease, alcoholism