This question is about biological molecules and the reactions that produce them.
A scientist investigates the anaerobic respiration of a bacterial culture fed with carbohydrates. A gas is collected in bubbles as the bacteria respire.
Describe a chemical test to identify this gas and state the expected observation.
- Test:
- Result:
Glucose is a simple sugar (monomer). Name two naturally occurring polymers produced from glucose.
Figure 1 shows the displayed structural formula of serine, an amino acid.
How many functional groups are there in the serine molecule shown in Figure 1?
- 1
- 2
- 3
- 4
Serine molecules react by condensation polymerisation to form a polypeptide.
Name the other substance produced in this reaction.
Amino acids contain nitrogen, which is not present in glucose.
Which two gases from Earth's early atmosphere could have provided nitrogen to form amino acids in early organisms?
The synthesis of proteins in organisms is controlled by DNA.
Describe the shape and structure of a DNA molecule.