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CMBM 3 > Dietary Protein > Flashcards

Flashcards in Dietary Protein Deck (48)
1

Summarize the major steps in protein digestion.

-Enzymes mediate hydrolysis of proteins into single AA's that can be absorbed
-in the stomach, pepsin is the major proteolytic enzyme
- in the small intestines, substances secreted by the pancreas further break down the partially digested material from the stomach.
-bicarbonate neutralizes the stomach acid. This raises the pH for optimal range for digestive enzymes.
-enteropeptidase cleaves typsinogen>>>trypsin
- trypsin then cleaves other zymogens

2

Summarize the major steps in protein absorption.

Specific transport proteins transfer AAs into the intestinal cells where some are used and the rest are transported via the blood to the liver.

3

Describe the conversion of digestive zymogens to their active form.

slide

4

What is an essential amino acid? List them.

An amino acid that the body cannot make at all or cannot make in sufficient quantities to meet its needs.

Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine

5

What is the recommended protein intake?

50% carbohydrate
20% fats
30% proteins

6

Where is the major source of Amino acid metabolism?

liver

7

Other than soybeans, plant sources do not provide all the essential amino acids. Give an example of plant combinations that do.

beans + corn
beans + rice

8

How many calories are in a gram of protein?

4 calories

9

Unlike carbohydrate and fat, protein does not have a specialized form of ?

storage

10

If not supplied by diet, protein will be acquired from?

working and structural components of the cells and tissues

11

What does starvation always cause?

wasting of lean body tissue in addition to fat loss

12

How do you spare proteins from being used for energy and allow them to perform their unique and important roles?

Take in adequate carbohydrate and fat

13

In what form is pepsin secreted? Where is the zymogen stored? How is it changed?

Produced and secreted by gastric cells as pepsinogen.

HCl produced by parietal cells induces conformational change that causes pepsinogen to be cleaved to active pepsin.

14

What cleaves trypsinogen?

enteropeptidase

15

Where is enteropeptidase released?

small intestines

16

What would happen if enteropeptidase malfunctioned?

-trypsin would not be produced
-chymotrypsin would not be produced
-elastase would not be produced
-carboxypeptidase would not be produced

**failure to thrive, diarrhea, hypoproteinemia

17

Where is chymotrypsinogen synthesized?

pancreas

18

Where is proelastase synthesized?

pancreas

19

Where is procarboxypeptidase synthesized?

pancreas

20

If the patient was unable to produce HCl, what would the patient experience?

- deficiencies in protein digestion and absorption
-malnourishment

21

What is the first step in the use of protein for energy production?

deamination (removal of N-containing amino group)

22

What two products result from deamination?

ammonia (NH3)
keto acid

23

Because ammonia is toxic, what does the liver do?

combines ammonia with carbon dioxide to produce urea and water

24

At what protein consumption level does the maximum urea production occur?

250 grams/day

25

How would you diagnose disease of liver?

blood ammonia is high

26

How would you diagnose kidney disease?

blood urea is high

27

How much water should a person drink if they are on a high protein diet?

>100 grams/day

28

What is chronic protein-energy malnutrition called? What are the symptoms?

Marasmus
- infancy (<2)
- develops slowly
-severe weight loss
-severe muscle wasting
- no detectable edema
-no fatty liver
-skin is dry, thin and easily wrinkles

29

What is acute protein-energy malnutrition called? What are the symptoms?

Kwashiorkor
-older infants and young children (1-3 years)
-rapid onset
-some weight loss
-some muscle wasting
-edema
-fatty liver
-loss of appetite
-skin develops lesions

30

Why would you see edema in Kwashiorkor?

decreased plasma protein in circulation

31

What 2 tests could you perform to confirm Kwashiorkor?

BUN (Blood urea nitrogen)
Creatinine clearance tests

32

What results would confirm Kwashiokor from the BUN test?

lower than normal levels (<6 mg/dL) are seen in low protein diet or malnutrition

33

What does the BUN test measure?

the amount of urea nitrogen in the blood

Urea nitrogen is what is formed when protein breaks down

34

What does the creatinine clearance test measure?

compares the creatinine level in the urine with the creatinine level in the blood.

Higher levels indicate muscle breakdown

**In elderly patients, creatinine clearance appears to decrease with age**

35

What results would confirm Kwashiokor from the creatinine clearance test?

higher than normal levels indicate breakdown of muscle

Male: 97-137 ml/min
Female 88-128 ml/min

36

Why do Kwashiorkor patients have increased infections?

damaged immune system due to the body breaking down antibodies

37

What enzyme is lacking in patients with PKU?

phenylalanine hydroxylase (PAH)

38

What inheritance type is PKU?

autosomal recessive

39

In addition to light pigmentation, what other symptoms may be present in PKU?

-delayed mental and social skills
- small head size
-hyperactivity
-jerking movements
-seizures
-skin rashes

40

What are some foods that contain phenylalanine? What supplements should be added to the diet?

aspartame
Supplements:
- fish oil
-iron

41

What amino acids are not able to be broken down by Maple Syrup Urine Disease patients?

branched chain amino acids
(BCAA)

42

What inheritance type is MSUD?

autosomal recessive

43

Which four genes can mutate to result in MSUD?

BCKDHA
BCKDHB
DBT
DLD

- genes form a complex to catabolize branched chain amino acids (BCAAs)

44

What is the name of the MSUD complex?

BCKD - mutation in BCKD is the most common reason for MSUD

45

What symptoms appear with MSUD?

poor feeding
vomiting
lethargy
developmental delay

46

What treatment is available for MSUD?

diet low in branched chain amino acids (Val, Leu, Ile)

fish oil supplements
iron supplements

some patients pursue a liver transplant

47

An infant with PKU would be expected to be deficient in what non-essential amino acid?

tyrosine

48

A mother is informed that products containing aspartame could be detrimental to her child's health. What is the likely genetic disorder?

PKU