Topic 1- A Level Edexcel Biology B Questions and
Complete solutions
monosaccharides
single simple sugar molecule
disaccharides
sugar made up off two monosaccharide units joined by a glycosidic bond formed in a
condensation reaction
polysaccharides
polymer made up of long chains of monosaccharide units joined by glycosidic bonds
condensation reaction
reaction in which a molecule of water is removed from the reacting molecules as a
bond is formed between them
glycosidic bond
covalent bond formed in a condensation reaction
anion
negative ion formed when an atom gains an electron
cation
positive ion formed when an atom loses an electron
ionic bonds
attractive forces between oppositely charged ions
covalent bonds
formed when atoms share electrons
dipole
separation of charge in a molecule when the electrons in a covalent bond are not
evenly shared
polar molecule
molecule containing a dipole
hydrogen bonds
, weak electrostatic intermolecular bonds formed between polar molecules containing
at least one hydrogen atom
monomer
small molecule that is a single unit of a larger molecule called a polymer
polymer
long chain molecule made up of many smaller repeating monomer units joined
together by chemical bonds
macromolecule
very large molecule formed by polymerisation
starch
energy store in plants made of amylose and amylopectin. Insoluble and compact and
can be broken down rapidly to release glucose
sucrose
sweet tasting disaccharide formed by the joining of a glucose and fructose by a
glycosidic bond
glucose
hexose sugar
triose sugar
sugar with 3 carbon atoms and important in mitochondria
pentose sugar
sugar with 5 carbon atoms and important in nucleic acid
ribose
pentose sugar that makes up part of the structure of RNA
deoxyribose
pentose sugar that makes up part of the structure of DNA
deoxyribonucleic acid
nucleic acid that acts as the genetic material in many organisms
ribonucleic acid
nucleic acid which can act as the genetic material in some organisms and is involved
in protein synthesis
hexose sugar
sugar with 6 carbon atoms and taste sweet
isomers
molecules that have the same chemical formula, but different molecular structures
Complete solutions
monosaccharides
single simple sugar molecule
disaccharides
sugar made up off two monosaccharide units joined by a glycosidic bond formed in a
condensation reaction
polysaccharides
polymer made up of long chains of monosaccharide units joined by glycosidic bonds
condensation reaction
reaction in which a molecule of water is removed from the reacting molecules as a
bond is formed between them
glycosidic bond
covalent bond formed in a condensation reaction
anion
negative ion formed when an atom gains an electron
cation
positive ion formed when an atom loses an electron
ionic bonds
attractive forces between oppositely charged ions
covalent bonds
formed when atoms share electrons
dipole
separation of charge in a molecule when the electrons in a covalent bond are not
evenly shared
polar molecule
molecule containing a dipole
hydrogen bonds
, weak electrostatic intermolecular bonds formed between polar molecules containing
at least one hydrogen atom
monomer
small molecule that is a single unit of a larger molecule called a polymer
polymer
long chain molecule made up of many smaller repeating monomer units joined
together by chemical bonds
macromolecule
very large molecule formed by polymerisation
starch
energy store in plants made of amylose and amylopectin. Insoluble and compact and
can be broken down rapidly to release glucose
sucrose
sweet tasting disaccharide formed by the joining of a glucose and fructose by a
glycosidic bond
glucose
hexose sugar
triose sugar
sugar with 3 carbon atoms and important in mitochondria
pentose sugar
sugar with 5 carbon atoms and important in nucleic acid
ribose
pentose sugar that makes up part of the structure of RNA
deoxyribose
pentose sugar that makes up part of the structure of DNA
deoxyribonucleic acid
nucleic acid that acts as the genetic material in many organisms
ribonucleic acid
nucleic acid which can act as the genetic material in some organisms and is involved
in protein synthesis
hexose sugar
sugar with 6 carbon atoms and taste sweet
isomers
molecules that have the same chemical formula, but different molecular structures
