Syllabus Edition

First teaching 2023

First exams 2025

|

Carbohydrates & Lipids (CIE AS Biology)

Exam Questions

3 hours45 questions
11 mark

The structure of cellulose is held together by which type of bond?

1 ionic bonds
2 glycosidic bonds
3 hydrogen bonds

  • 1, 2 and 3

  • 1 and 2 only

  • 2 and 3 only

  • 1 and 3 only

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21 mark

Which bonds are found in glycogen?

q2-2-2-easy

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    31 mark

    Where are the double bonds located in unsaturated lipid molecules?

    • Within fatty acids chains and within glycerol molecules

    • Between glycerol molecules and fatty acids chains

    • Within glycerol molecules only

    • Within fatty acid chains only

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    41 mark

    Which of the molecules below is α-glucose?

    q4-2-2-easy

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      51 mark

      A biological molecule is shown in the image below.

      q5-2-2-easy

      Which of the following could be the molecule in the image?

      1 amylose
      2 amylopectin
      3 cellulose
      4 glycogen

      • 1, 2 and 4

      • 1 and 2 only

      • 1 and 3 only

      • 2 and 4 only

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      61 mark

      The diagrams below show a number of biological molecules.q6-2-2-easy

      Which of the molecules above contains a glycosidic bond?

      • 1 and 3 only

      • 1, 2 and 4

      • 1 and 2 only 

      • 1 only

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      71 mark

      Which of the following features distinguishes starch from glycogen?

      • Starch contains 1,6-glycosidic bonds

      • Starch contains α-glucose and not β-glucose

      • Starch is a polysaccharide

      • Starch has an unbranched component

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      81 mark

      Which molecule in the image below contains ester bonds?

      q8-2-2-easy

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        91 mark

        Which of the following types of bond is responsible for joining smaller molecules together to form biological polymers?

        • Covalent

        • Hydrogen

        • Hydrophobic interactions

        • Ionic

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        101 mark

        Which of the following statements about triglycerides is not correct?

        • They play a vital role in energy storage within an organism

        • They are hydrophobic

        • Only triglycerides with unsaturated fatty acid chains contain double bonds

        • They are made up of three fatty acids combined with glycerol

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        11 mark

        Two biological molecules are shown in the diagram below.

        q1-2-2-medium

        Which row of the table correctly identifies features of these molecules?

          Molecule 1 Molecule 2
        A has 3 fatty acid chains fatty acid chains are all saturated
        B has 2 ester bonds and a phosphate group has 3 phosphodiester bonds
        C has 3 saturated fatty acid chains has 1 unsaturated fatty acid chain
        D molecule is polar molecule is polar

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          21 mark

          Two molecules of glucose are shown in the diagram below.

          Possible bonding positions are labelled h, i, j, and k on the first molecule, and m, n, o and p on the second.

          q2-2-2-medium

          When these two molecules condense to form amylopectin, between which of the letters on the diagram could bonds form?

          •  o — i or k — p

          • p — i or p — k

          • i — n or m — h

          • p — k or n — i

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          31 mark

          Which of the following occurs when sucrose is formed from monosaccharides?

          • Condensation of non-reducing sugars, using water

          • Condensation of reducing sugars, using water

          • Condensation of reducing sugars, releasing water

          • Condensation of non-reducing sugars, releasing water

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          41 mark

          The molecular structure of starch means that starch is well suited to its function.

          Which of the following statements best explains this?

          • Many condensation reactions break down amylose and amylopectin, releasing stored energy

          • The amylose-amylopectin complex is soluble for easy transport in the phloem

          • Amylopectin is coiled to give a compact structure; this allows easy transport around the plant through the phloem

          • The amylose-amylopectin complex is insoluble so it does not affect the water potential of the cell

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          51 mark

          A naturally occurring polysaccharide has an unbranched chain structure which contains molecules of acetylglucosamine held together by β-1,4-glycosidic bonds.

          There are many weaker bonds between the unbranched chains, and -CH2OH groups are located on alternate sides of the polysaccharide chain.

          Which of the following polysaccharides has a structure similar to that described above?

          • Glycogen

          • Cellulose

          • Amylopectin

          • Amylose

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          61 mark

          Which of the following shows the structure of β-glucose and α-glucose?

          q6-2-2-medium



























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            71 mark

            Which of the following statements correctly describes a feature of carbohydrates or lipids?

            • Glycosidic bonds form during hydrolysis reactions, joining monosaccharides together to form disaccharides and polysaccharides.

            • A triglyceride is not an example of a polymer as it is not formed from smaller subunits joined together by covalent bonds.

            • A triglyceride is not an example of a polymer although it is formed from smaller subunits joined together.

            • Glycosidic bonds join disaccharides together to form monosaccharides and polysaccharides.

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            81 mark

            Which of the following procedures could be applied sucrose to achieve a positive test result?

            1 dissolve in water, neutralise with acid and then heat with Benedict's reagent
            2 boil with hydrochloric acid, neutralise and then heat with Benedict's reagent
            3 add hydrolytic enzymes and then heat with Benedict's reagent

            • 1, 2 and 3

            • 1 and 2 only

            • 2 and 3 only

            • 1 and 3 only

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            91 mark

            Which of the statements below correctly describes a disaccharide?

            • Sugars formed from two subunits joined together by a covalent bond that forms during a hydrolysis reaction.

            • Sugars formed from two subunits joined together by a glycosidic bond that forms during a hydrolysis reaction.

            • Sugars formed from two subunits joined together by a glycosidic bond that forms during a condensation reaction.

            • Starches formed from two subunits joined together by a covalent bond that forms during a condensation reaction.

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            101 mark

            All biological molecules have structures that relate to their functions.

            Three statements relating to molecule structure are given below:

            1 insoluble in water
            2 forms long, straight chains of sugar subunits held together by glycosidic bonds
            3 many hydrogen bonds are able to form

            Which of the options below would all three statements above apply to?

            • Amylose and amylopectin

            • Cellulose

            • Amylose and cellulose

            • Amylose

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            11 mark

            The diagram below shows the molecular structures of two molecules.q1-hard-2-2

            1

            The phospholipid has fatty acid chains of the same length whereas the triglyceride has fatty acid chains of different lengths.

            2 The phospholipid has two ester bonds in its structure whereas the triglyceride has three.
            3 The triglyceride is non-polar and will form hydrogen bonds with water molecules.
            4 The fatty acid chains in the triglyceride are all saturated, whereas in the phospholipid there is an unsaturated bond.

               

            Which of the above statements are true?

            • 1 and 3 only

            • 1, 2 and 4

            • 2 and 4 only

            • 2 only

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            21 mark

            A number of biological molecules are shown in the diagram below.q2-hard-2-2

            Which row of the table below correctly identifies some of the products of hydrolysis of the molecules above?

              Q R S T
            A straight alpha-glucose straight beta-glucose glycerol straight alpha-glucose
            B straight alpha-glucose straight beta-glucose fatty acids straight alpha-glucose
            C straight beta-glucose straight alpha-glucose glycerol straight beta-glucose
            D straight beta -glucose straight alpha-glucose phosphate group straight alpha-glucose

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              31 mark

              q3-hard-2-2

              1 Molecule P contains peptide bonds, whereas Molecules R and Q are polymers with one type of covalent bond holding their sub-units together
              2 Molecules R and T could both be found in animals and plants, whereas Molecule Q will never be found in animals.
              3 Molecule S is commonly used for every storage in plants, whereas Molecule Q has a structural role only.
              4 Molecule T has a helical structure, and Molecule R is commonly used for energy storage in plants.


              Which of the statements above are not true?

              • 1 and 3 only

              • 1, 2 and 3

              • 2 and 4 only

              • 4 only

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              41 mark

              Which of the following molecules would have a structural formula that contains C=O bonds?

              1 fatty acids
              2 glucose
              3 glycerol
              • 1 and 2 only

              • 2 and 3 only

              • 1 only

              • 3 only

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              51 mark

              The names of four biological molecules are given below:

              1 glucose
              2 fructose
              3 maltose
              4 sucrose


              Which of the following combinations contains a disaccharide that would act as a reducing agent when mixed with copper (II) sulfate ions, and a disaccharide that wouldn't?

              • 1 and 3

              • 1 and 4

              • 2 and 3

              • 3 and 4

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              61 mark
              1

              Sucrose hydrolysis results in the breakage of glycosidic bonds, releasing equal amounts of fructose and straight alpha-glucose molecules, whereas the hydrolysis of amylose in plant cells results in only straight beta-glucose molecules.

              2

              The glycosidic bonds of glycogen have been formed between two straight alpha-glucose molecules and only contain 1,4-glycosidic bonds, whereas the structure of amylose contains both 1 and 1,6-glycosidic bonds.

              3 Triglycerides are polymers of three fatty acid chains joined to a glycerol molecule, forming a macromolecule which is not soluble in water.


              Which of the statements above are not true?

              • 1 and 2

              • 2 and 3

              • 1, 2 and 3

              • None of the above

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              71 mark

              Lactose is a disaccharide that can be broken down to two different monosaccharides, one of which is galactose.

              Which of the following correctly describes what occurs when lactose breaks down?

              • Hydrolysis, releasing galactose and glucose and using water

              • Condensation of galactose and glucose, using water

              • Hydrolysis, releasing maltose and galactose and using water

              • Condensation, releasing maltose and galactose, releasing water

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              81 mark

              Which of the following is a correct description?

              • Sucrose and maltose are disaccharides that do not react with Cu2+ ions in Benedict's reagent, resulting in no colour change signifying that reducing sugars are present

              • Sucrose and maltose are disaccharides, sucrose is a reducing sugar that can donate electrons to Cu2+ ions in Benedict's reagent, resulting in a colour change whereas maltose does not reduce Cu2+ ions

              • Sucrose and maltose are disaccharides that do not react with Cu2+ ions in Benedict's reagent, resulting in no colour change signifying that non-reducing sugars are present

              • Sucrose and maltose are disaccharides, maltose is a reducing sugar that can donate electrons to Cu2+ ions in Benedict's reagent, resulting in a colour change whereas sucrose does not reduce Cu2+ ions

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              91 mark

              Which of the following is a correct description of a monosaccharide?

              • An OH group projects below the plane of the ring of 1C and 4C in straight alpha-glucose, and above the plane of the ring of 2C and 4C in straight beta-glucose.

              • An OH group projects below the plane of the ring of 1C and 4C in straight beta-glucose, and above the plane of the ring of 2C and 1C in straight alpha-glucose

              • An OH group projects below the plane of the ring of 1C and 3C in straight beta-glucose, whereas the OH group projects above the plane of 1C in straight alpha-glucose.

              • An OH group projects above the plane of the ring of 1C and 3C in straight beta-glucose, whereas the OH group projects below the plane of 1C in straight alpha-glucose.

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              101 mark

              Glycosidic bonds join monosaccharides together to form disaccharides and polysaccharides. Peptide bonds join amino acid subunits together to form polypeptide chains. Triglyceride molecules contain three fatty acid chains joined to one glycerol molecule via three ester bonds.

              Which of the following statements correctly describes a feature all of the polymers described above share?

              • They all contain monomers which are formed by many smaller molecules joined together by hydrogen bonds, which form during condensation reactions.

              • They all contain monomers which are formed by many smaller molecules joined together by hydrogen bonds, which form during condensation reactions.

              • They all contain monomers which are formed by many smaller molecules joined together by covalent bonds, which form during condensation reactions.

              • They all contain monomers which are formed by many smaller molecules joined together by covalent bonds, which form during hydrolysis reactions.

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