Unit 1 - Biological Molecules

Question 1

Monomer (1)

Answer 1

• The smaller units from which larger
  molecules are made

Question 2

Polymer (1)

Answer 2

• Molecules made from a large
  number of monomers joined
  together

Question 3

Monosaccharide (1)

Answer 3

• The monomers from which larger
  carbohydrates are made

Question 4

Disaccharide (2)

Answer 4

• Formed by the condensation of two
  monosaccharides
• held together by a glycosidic bond

Question 5

Polysaccharide (2)

Answer 5

• Formed by the condensation of
  many glucose units
• held by glycosidic bonds

Question 6

Cellulose (2)

Answer 6

• Polysaccharide in plant cell walls
• formed by the condensation of
  β-glucose

Question 7

Glycogen (2)

Answer 7

• Polysaccharide in animals
• formed by the condensation of
  α-glucose

Question 8

Starch (3)

Answer 8

• Polysaccharide in plants
• formed by the condensation of
  α-glucose
• contains two polymers - amylose
  and amylopectin

Question 9

Glycosidic bond (4)

Answer 9

• C–O–C link
• between two sugar molecules
• formed by a condensation reaction
• it is a covalent bond

Question 10

Amylose (4)

Answer 10

• Polysaccharide in starch
• made of α-glucose
• joined by 1,4-glycosidic bonds
• coils to form a helix

Question 11

Amylopectin (4)

Answer 11

• Polysaccharide in starch
• made of α-glucose
• joined by 1,4 and 1,6-glycosidic
  bonds
• branched structure

Question 12

Condensation
reaction (3)

Answer 12

• A reaction that joins two molecules
  together
• with the formation of a chemical
  bond
• involves the elimination of a
  molecule of water

Question 13

Hydrolysis
reaction (3)

Answer 13

• A reaction that breaks a chemical
  bond
• between two molecules
• involves the use of a water molecule

Question 14

Fibrils (2)

Answer 14

• Long, straight chains of β-glucose
  glucose
• held together by many hydrogen
  bonds

Question 15

Triglyceride (2)

Answer 15

• Formed by the condensation of 1
  molecule of glycerol and 3
  molecules of fatty acids
• forming 3 ester bonds

Question 16

Phospholipid (3)

Answer 16

• Formed by the condensation of one
  molecule of glycerol and two
  molecules of fatty acid
• held by two ester bonds
• a phosphate group is attached to
  the glycerol

Question 17

Induced-fit
model (4)

Answer 17

• The enzyme active site is not
  initially complementary to the
  substrate
• the active site moulds around the
  substrate
• this puts tension on bonds
  lowers the activation energy

Question 18

Competitive
inhibitor (3)

Answer 18

• A molecule that is the same/similar
  shape as the substrate
• binds to the active site
• prevents enzyme-substrate
  complexes from forming

Question 19

Non-competitive
inhibitor (3)

Answer 19

• A molecule that binds to an enzyme
  at the allosteric site
• causing the active site to change
  shape
• preventing enzyme-substrate
  complexes from forming

Question 20

Primary
structure (1)

Answer 20

• The sequence of amino acids on a
  polypeptide chain

Question 21

Secondary structure (3)

Answer 21

• The folding or coiling
• to create a β pleated sheet or an
  α helix
• held in place by hydrogen bonds

Question 22

Tertiary structure (3)

Answer 22

• The further folding
• to create a unique 3D shape
• held in place by hydrogen, ionic and
  sometimes disulphide bonds

Question 23

Quaternary
structure (1)

Answer 23

• More than one polypeptide chain in
  a protein

Question 24

Peptide bond (3)

Answer 24

• Covalent bond joining amino acids
  together in proteins
• C–N link between two amino acid
  molecules
• formed by a condensation reaction

Question 25

What is the effect of
temperature on enzyme-controlled reaction? (4)

Answer 25

• Low temp: not enough kinetic energy for successful collisions between the
  enzyme and substrate.
• Too high temp: enzymes denature
• the active site changes shape
• enzyme- substrate complexes cannot
  form.