Related Clues:

• Egg with touches of red in centre becomes kind of acid
• Acid found in spinach
• ___ acid (vitamin B9)
• Container brought back full, apart from last type of acid
• Atomic group found in glutamic acid
• Organic acid type
• Protein constituent, informally
• One type of acid
• Acid needed for DNA synthesis
• Powdered acid used as an insecticide
• The 28-Across in proteins
• Like protein-building acids
• Protein acid type
• With 67 Across, protein building block
• With 14-Across, vitamin B9