IGCSE Biological molecules

Small molecules are used as the basic units in the synthesis of large food molecules. Which statement is correct?

• Amino acids are basic units of carbohydrates.

• Fatty acids are basic units of glycogen.

• Glycerol is a basic unit of oils.

• Simple sugar is a basic unit of protein.

Tags

NGSS.HS-LS1-6

When a substance is added to meat, amino acids are produced. What is this substance?

• a hormone

• an enzyme

• an oil

• water

Tags

NGSS.HS-LS1-6

The diagram shows part of a protein molecule. X What does X represent?

• amino acid

• fatty acid

• glycerol

• sugar

Tags

NGSS.HS-LS1-1

Four different foods were tested for their composition. The results are shown in the choices. Which food contains protein but not reducing sugar or starch?

• Benedict’s test: blue/iodine test: black/ biuret test: purple

• Benedict’s test: blue/iodine test: brown/ biuret test: purple

• Benedict’s test: brick red/iodine test: black/ biuret test: blue

• Benedict’s test: brick red/iodine test: brown/ biuret test: blue

What are the smaller basic units of starch and glycogen molecules?

• Starch: amino acid/ Glycogen: fatty acid and glycerol

• Starch: amino acid/ Glycogen: simple sugars

• Starch: simple sugars/ Glycogen: fatty acid and glycerol

• Starch: simple sugars/ Glycogen: simple sugars

The diagram represents a protein molecule. What do the small circles represent?

• amino acids

• fatty acids

• glycerol

• simple sugars

Tags

NGSS.HS-LS1-6

Which row shows the elements and basic units that are used in the construction of large food molecules?

• food: fat/ molecules elements:carbon, hydrogen, oxygen, nitrogen/ basic units: glucose

• food: fat/ molecules elements:carbon, hydrogen, oxygen, nitrogen/ basic units: glycerol

• food: starch/ molecules elements:carbon, hydrogen, oxygen/ basic units: glucose

• food: starch/ molecules elements:carbon, hydrogen, oxygen/ basic units: glycerol

Tags

NGSS.HS-LS1-6

Which nutrient produces a purple colour when mixed with biuret solution?

• fat

• protein

• reducing sugar

• starch

Tags

NGSS.HS-LS1-1

Which simple molecules are the basic units of protein?

• amino acids

• fatty acids

• sugars

• vitamins

Tags

NGSS.HS-LS1-6

Which food-testing reagent shows a positive result when it turns from blue to purple?

• Benedict’s solution

• biuret reagent

• ethanol

• iodine solution