Describe nitrogen balance and discuss the factors which influence nitrogen balance

Question 1

Nitrogen balance is a fundamental concept in the study of

Answer 1

Protein metabolism

Question 2

Nitrogen balance is a fundamental concept in the study of protein metabolism, reflecting the difference between

Answer 2

nitrogen intake and loss.

Question 3

Nitrogen balance serves as an indicator of the

Answer 3

net gain or loss of protein within the body.

Question 4

Nitrogen balance gives valuable insights into

Answer 4

an individuals nutritional status

Question 5

Nitrogen, a critical component of

Answer 5

amino acids, the building blocks of protein, is essential for various biological functions.

Question 6

What is the concept of nitrogen balance

Answer 6

it is used to determine whether a person is gaining, losing, or maintaining protein mass.

Question 7

Nitrogen balance equation

Answer 7

B (Nitrogen balance) = I (nitrogen intake) - O (Nitrogen output)

Question 8

What does it mean if the intake equals the loss

Answer 8

the individual is in nitrogen equilibrium.

Question 9

Why is nitrogen balance important

Answer 9

for maintaining homeostasis and supporting growth, tissue repair, and other physiological functions.

Question 10

A positive nitrogen balance indicates and when this is most prevalent

Answer 10

nitrogen intake exceeds output, suggesting net protein synthesis.

This condition is typically observed in growing children, pregnant women, individuals recovering from protein depletion, or during periods of muscle mass gain.

Question 11

What hormones enhance the anabolic state by promoting protein synthesis and reducing protein degradation.

Answer 11

Insulin, growth hormone, and testosterone

Question 12

a negative nitrogen balance occurs when and what is this associated with

Answer 12

losses exceed intake, indicative of net protein breakdown.

often associated with acute or chronic illnesses, such as burns, infections, hyperthyroidism, or malnutrition.

Question 13

What other factors can affect effect negative nitrogen balance

Answer 13

stress hormones (glucagon, cortisol, catecholamines) can exacerbate protein catabolism, leading to increased nitrogen excretion and negative balance.

Question 14

What 3 factors influence Nitrogen Balance

Answer 14

Dietary intake

Physiological and Metabolic state

Gastrointestinal and Metabolic Factors

Question 15

Dietary intake (2 bullet points)

Answer 15

Protein Quality: High-quality proteins containing essential amino acids in optimal ratios are crucial for maintaining a positive nitrogen balance. Limiting amino acids (e.g., lysine in wheat, methionine in fish) can restrict protein synthesis if they are deficient in the diet.

Protein Quantity: Adequate dietary protein is necessary to replace obligatory losses and support tissue maintenance and growth.

Question 16

Physiological and metabolic state (2 bullet point)

Answer 16

Physical Activity: : Increases in muscle mass due to resistance training can improve nitrogen retention, whereas endurance activities might increase amino acid oxidation.

Health Status: Illness or injury can increase protein requirements due to enhanced metabolic activity and repair processes.

Question 17

Gastrointestinal and Metabolic Factors (2 Bullet Point)

Answer 17

Digestibility and Absorption: The efficiency of protein digestion and amino acid absorption can significantly affect nitrogen balance. Factors such as dietary fibre and anti-nutritional elements can impair protein utilisation.

Urea Recycling: Colonic bacteria can recycle urea into ammonia, which is then utilized to synthesize non-essential amino acids, potentially impacting nitrogen balance, particularly under conditions of low protein intake.