Photo AI

Glycine is one of the amino acids that forms proteins - VCE - SSCE Chemistry - Question 19 - 2003 - Paper 1

Question icon

Question 19

Glycine-is-one-of-the-amino-acids-that-forms-proteins-VCE-SSCE Chemistry-Question 19-2003-Paper 1.png

Glycine is one of the amino acids that forms proteins. Protein that is not required in the body is broken down in the liver. Unwanted nitrogen is converted to urea a... show full transcript

Worked Solution & Example Answer:Glycine is one of the amino acids that forms proteins - VCE - SSCE Chemistry - Question 19 - 2003 - Paper 1

Step 1

Calculate the amount of nitrogen in glycine

96%

114 rated

Answer

Glycine has the formula H₂N-CH₂-COOH. The nitrogen content in glycine is from the amino group (H₂N). Therefore, for 1.00 g of glycine with a molecular mass of 75 g/mol, we can calculate the moles:

extmolesofglycine=1.00extg75extg/mol0.0133extmol ext{moles of glycine} = \frac{1.00 ext{ g}}{75 ext{ g/mol}} \approx 0.0133 ext{ mol}

Each mole of glycine contains 1 mole of nitrogen.

Step 2

Calculate the total mass of nitrogen in glycine

99%

104 rated

Answer

The mass of nitrogen contributed by glycine can be found by first determining the moles of nitrogen in the 1.00 g of glycine, which is also 0.0133 mol.

The molar mass of nitrogen (N) is 14 g/mol. Therefore, the total mass is:

extmassofnitrogen=0.0133extmol×14extg/mol0.186extg ext{mass of nitrogen} = 0.0133 ext{ mol} \times 14 ext{ g/mol} \approx 0.186 ext{ g}

Step 3

Convert nitrogen to urea

96%

101 rated

Answer

The conversion of nitrogen into urea occurs through the urea cycle, which produces urea that contains 2 nitrogen atoms. Thus, the total urea produced can be calculated from the nitrogen mass:

extMassofurea=0.186extgN2×60extgurea28extgN0.40extg ext{Mass of urea} = \frac{0.186 ext{ g N}}{2} \times \frac{60 ext{ g urea}}{28 ext{ g N}}\approx 0.40 ext{ g}

Step 4

Final answer

98%

120 rated

Answer

Thus, the maximum mass of urea that could be eliminated as a result of the breakdown of 1.00 g of glycine is approximately 0.40 g. Therefore, the correct answer is B. 0.80.

Join the SSCE students using SimpleStudy...

97% of Students

Report Improved Results

98% of Students

Recommend to friends

100,000+

Students Supported

1 Million+

Questions answered

Other SSCE Chemistry topics to explore

;