Protein Metabolism Part 1 W7

Question 1

When do conditionally non-essential amino acids become conditionally essential?

Answer 1

Pregnancy
Patients with PKU (Phenylketonuria)

Question 2

What is the main site of protein synthesis?

Answer 2

Liver

Question 2

What are amino acids precursors and regulators for?

Answer 2

Synthesis of body proteins (precursor only)
Neurotransmitters
Hormones
DNA
RNA

Question 3

How can you measure protein loss?

Answer 3

Sweat
Skin
Hair
Urine
Faeces

Question 4

What does the liver generate as an energy substrate and then metabolised endogenously in the liver?

Answer 4

Ammonia (this is converted into urine)

Question 5

How much nitrogen is in 1g of protein?

Answer 5

6.25g

Question 6

What is nitrogen (protein) balance?

Answer 6

What goes in must eventually come out

Question 7

What does the side chain of an amino acid allow?

Answer 7

Allows us to determine structure

Question 8

How do you calculate nitrogen balance?

Answer 8

1) Determine nitrogen excretion
2) Determine nitrogen intake
3) N Balance (2-1)

Nitrogen intake- Nitrogen Excretion

Question 9

How do you determine nitrogen excretion?

Answer 9

In grams per 24hr period

Question 10

How do you determine nitrogen intake?

Answer 10

Protein intake (g) divided by 6.25

Question 11

What does determining the N balance for protein allow?

Answer 11

Estimation of the required protein intake needed to maintain protein balance

Question 12

What is the protein reference nutrient intake (RNI)?

Answer 12

0.75 g/kg/d

Question 13

What are the limitations of nitrogen balance?

Answer 13

No information of tissues

Lack of sensitivity (gross measures of intake and excretion)

Zero balance on low intake my reflect accommodation

Positive balance may not relate to lean body mass

Question 14

How is net protein balance calculated?

Answer 14

Protein synthesis - protein breakdown

Question 15

How much of your total body mass does skeletal muscle tissue make up?

Answer 15

40%

Question 16

What has a greatest protein turnover rate, skeletal muscle or the gut?

Answer 16

Gut

Question 17

How much of protein is nitrogen?

Answer 17

16%

Question 18

What is nitrogen balance adequate in measuring?

Answer 18

Measuring amino acids required to prevent “deficiency”

Question 19

What is nitrogen balance inadequate in measuring?

Answer 19

Estimating the amino acid requirements for exercise-induced muscle remodelling

Question 20

What is MPS?

Answer 20

Muscle Protein Synthesis

Question 21

What is MPB?

Answer 21

Muscle Protein Breakdown

Question 22

What does a + net protein balance indicate?

Answer 22

Protein accretion

Question 23

What does a - net protein balance indicate?

Answer 23

Protein loss

Question 24

Is nitrogen balance a good indicator of muscle protein balance?

Answer 24

No

Question 25

What is the RDA for protein?

Answer 25

0.8g/kg/bw

Question 26

What is the sufficiency of the RDA and RNI estimations of meeting the overall population?

Answer 26

97%

Question 27

When is net muscle protein balance at its greatest?

Answer 27

Following exercise training and ingestion

Question 28

In the post-exercise period, the MPS response to protein ingestion is enhanced. How long does this enhanced response last for?

Answer 28

24-48 hours