MOLECULAR BIOLOGY EXAM: LATEST A+ QUESTIONS
AND ANSWERS BREAKDOWN
living organisms are composed of organic chemicals that could only be produced in living
organisms because of a vital force
theory of vitalism
german chemist Friedrich Wöhler synthesized urea artificially using silver isocyanate and
ammonium chloride
Synthesis of urea
synthesis of complex molecules form simpler molecules
Anabolism
the web of all enzyme catalyses reactions in a cell or organism
Metabolism
condensation reactions because water is produced
Anabolic reactions are
breakdown of complex molecules into smaller ones including hydrolysis of macromolecules
into monomers
Catabolism
water molecules are split
in hydrolysis reactions
single particle of an element, consists of positive charged nucleus surrounded by negatively
charged electrons
Atom
group of two or more atoms hold together by covalent bonds
Molecule
strong
Covalent bonds
weak bonds between molecules
Intermolecular forces
, carbohydrates, lipids, proteins, nucleic acids
main types of molecules
two atoms share a pair of electrons, sometimes not equally
Covalent bonds are formed when
sharing of molecule, one part of molecule slight positive, the other one slightly negative
Polarity
polar, hydrogen nuclei less attractive to electrons than oxygen
Water molecules are
water molecules have two poles and therefore dipoles
Dipolarity
M: -182°C, W: 0°C
Melting point
ice melts at higher temperature, hydrogen bonds restrict movement of water molecules, heat
needed to overcome this
Explanation melting point
M: 2.2J per g per °C, W: 4.2J per g per °C
Specific heat capacity
water heat capacity higher, hydrogen bonds restrict movement so more energy is stored by
moving molecules of water than methane
Explanation specific heat capacity
M: 760J/g, W: 2257J/g
Latent heat of vaporization
water has higher heat of vaporization, much heat is needed to break hydrogen bonds and
allow water molecule to evaporate
Explanation heat of vaporization
M: -160°C, W: 100°C
Boiling point
AND ANSWERS BREAKDOWN
living organisms are composed of organic chemicals that could only be produced in living
organisms because of a vital force
theory of vitalism
german chemist Friedrich Wöhler synthesized urea artificially using silver isocyanate and
ammonium chloride
Synthesis of urea
synthesis of complex molecules form simpler molecules
Anabolism
the web of all enzyme catalyses reactions in a cell or organism
Metabolism
condensation reactions because water is produced
Anabolic reactions are
breakdown of complex molecules into smaller ones including hydrolysis of macromolecules
into monomers
Catabolism
water molecules are split
in hydrolysis reactions
single particle of an element, consists of positive charged nucleus surrounded by negatively
charged electrons
Atom
group of two or more atoms hold together by covalent bonds
Molecule
strong
Covalent bonds
weak bonds between molecules
Intermolecular forces
, carbohydrates, lipids, proteins, nucleic acids
main types of molecules
two atoms share a pair of electrons, sometimes not equally
Covalent bonds are formed when
sharing of molecule, one part of molecule slight positive, the other one slightly negative
Polarity
polar, hydrogen nuclei less attractive to electrons than oxygen
Water molecules are
water molecules have two poles and therefore dipoles
Dipolarity
M: -182°C, W: 0°C
Melting point
ice melts at higher temperature, hydrogen bonds restrict movement of water molecules, heat
needed to overcome this
Explanation melting point
M: 2.2J per g per °C, W: 4.2J per g per °C
Specific heat capacity
water heat capacity higher, hydrogen bonds restrict movement so more energy is stored by
moving molecules of water than methane
Explanation specific heat capacity
M: 760J/g, W: 2257J/g
Latent heat of vaporization
water has higher heat of vaporization, much heat is needed to break hydrogen bonds and
allow water molecule to evaporate
Explanation heat of vaporization
M: -160°C, W: 100°C
Boiling point
