BIOCHEMISTRY CHAPTER 1 AS201
1.1 BIOMOLECULE
FUNCTIONAL GROUP METABOLISM
- responsible for the characteristic of chemical reactions • Metabolism = the chemical reactions of biomolecules
of those molecules. - Catabolism + Anabolism
• Catabolic reaction are energy yielding: the breakdown
of larger molecules into smaller ones
• Anabolic reaction are energy requiring: the synthesis of
larger molecules from smaller ones
1.2 THERMODYNAMICS
THERMODYNAMIC
BASIC CONCEPTS OF THERMODYNAMIC BIOENERGETIC
• important in thermoD → • BIOENERGETICS → study of energy transformation that
distinction of system and occur in living organism
surrounding - Describe transfer and utilization of energy in
• The system → the portion of biological system
the universe with which are • ENERGY (E) – capacity to do work
concerned - All cells require energy for various purposes.
• The surroundings → ◼ Synthesis of large molecule
everything else in universe ◼ Cell division (mitosis and meiosis)
• 3 basic systems: ◼ Active transport in cells, etc.
- Isolated system (cannot TYPES OF ENERGY
exchange matter / energy Chemical energy – stored in chemicals bond of molecules,
with its surrounding (e.g glucose)
- Closed system (can exchange energy) • Heat energy – flow of the thermal energy from a
- Open system (can exchange either or both) hotter object to a colder one
• Matter → nutrient and waste product • Electrical energy – the flow of
• Living things are ‘open system’ charged particles
- Absorb energy (light and chemical) • Mechanical energy – the
- Release heat and metabolic waste movement of body
• 2 law of thermodynamic govern energy transformation FORM OF MECHANICAL ENERGY
in organism • Potential energy – type of stored energy, that is the
energy of position
• Kinetic energy – the energy of movement/motion
1|Page
, BIOCHEMISTRY CHAPTER 1 AS201
LAW OF THERMODYNAMICS
The laws of thermodynamics describe the relationships between thermal energy, or heat, and other forms of energy,
and how energy affects matter.
The First Law of Thermodynamics → energy cannot be created or destroyed; the total quantity of energy in the
universe stays the same.
The Second Law of Thermodynamics is about the quality of energy. It states that as energy is transferred or
transformed, more and more of it is wasted. It also states that there is a natural tendency of any isolated system to
degenerate into a more disordered state.
1st LAW OF THERMODYNAMIC
• Energy can be transferred and transformed but cannot be created or destroyed
- ‘Plant converting energy from sunlight into chemical energy, plant as energy transformer not producer’
• Therefore, energy generated in any system is energy that has been transformed from one state to another (eg:
chemically stored energy transformed to heat)
The 1st law explains that the total ‘quantity’ of energy in the universe stays the same
HEAT, WORK & INTERNAL ENERGY
• The increase in the internal energy of the system is equal to the amount of energy added by heating the system minus
the amount lost as a result of the work done by the system on its surroundings
∆E = q – w
E=internal energy
q=heat absorb by the system
w=work done by the system
ENTALPHY
• Enthalpy (H) is a measure of the total energy of a thermodynamic system.
• +∆H indicates that heat is being absorbed in the reaction (it gets cold)→ ENDOTHERMIC
• -∆H indicates that heat is being given off in the reaction (it gets hot)→EXOTHERMIC
Endothermic reaction
The reactants have less potential energy than do the products.
Energy must be input in order to raise the particles up to the higher energy level.
Non-spontaneous : process occurs with an input of energy
Exothermic reaction
The reactants have more potential energy than the products have.
The extra energy is released to the surroundings.
Spontaneous : process occurs without input of energy
2nd LAW THERMODYNAMIC
• When energy is converted from one form to another (energy available to do work) is degraded into a less-usable form
(heat) that disperses into the environment.
• Expresses concept that events in universe have direction
• Systems tend to proceed from ordered to disordered states
The 2nd law is about the direction which the process can take place and the ‘quality’ of the energy
2|Page
1.1 BIOMOLECULE
FUNCTIONAL GROUP METABOLISM
- responsible for the characteristic of chemical reactions • Metabolism = the chemical reactions of biomolecules
of those molecules. - Catabolism + Anabolism
• Catabolic reaction are energy yielding: the breakdown
of larger molecules into smaller ones
• Anabolic reaction are energy requiring: the synthesis of
larger molecules from smaller ones
1.2 THERMODYNAMICS
THERMODYNAMIC
BASIC CONCEPTS OF THERMODYNAMIC BIOENERGETIC
• important in thermoD → • BIOENERGETICS → study of energy transformation that
distinction of system and occur in living organism
surrounding - Describe transfer and utilization of energy in
• The system → the portion of biological system
the universe with which are • ENERGY (E) – capacity to do work
concerned - All cells require energy for various purposes.
• The surroundings → ◼ Synthesis of large molecule
everything else in universe ◼ Cell division (mitosis and meiosis)
• 3 basic systems: ◼ Active transport in cells, etc.
- Isolated system (cannot TYPES OF ENERGY
exchange matter / energy Chemical energy – stored in chemicals bond of molecules,
with its surrounding (e.g glucose)
- Closed system (can exchange energy) • Heat energy – flow of the thermal energy from a
- Open system (can exchange either or both) hotter object to a colder one
• Matter → nutrient and waste product • Electrical energy – the flow of
• Living things are ‘open system’ charged particles
- Absorb energy (light and chemical) • Mechanical energy – the
- Release heat and metabolic waste movement of body
• 2 law of thermodynamic govern energy transformation FORM OF MECHANICAL ENERGY
in organism • Potential energy – type of stored energy, that is the
energy of position
• Kinetic energy – the energy of movement/motion
1|Page
, BIOCHEMISTRY CHAPTER 1 AS201
LAW OF THERMODYNAMICS
The laws of thermodynamics describe the relationships between thermal energy, or heat, and other forms of energy,
and how energy affects matter.
The First Law of Thermodynamics → energy cannot be created or destroyed; the total quantity of energy in the
universe stays the same.
The Second Law of Thermodynamics is about the quality of energy. It states that as energy is transferred or
transformed, more and more of it is wasted. It also states that there is a natural tendency of any isolated system to
degenerate into a more disordered state.
1st LAW OF THERMODYNAMIC
• Energy can be transferred and transformed but cannot be created or destroyed
- ‘Plant converting energy from sunlight into chemical energy, plant as energy transformer not producer’
• Therefore, energy generated in any system is energy that has been transformed from one state to another (eg:
chemically stored energy transformed to heat)
The 1st law explains that the total ‘quantity’ of energy in the universe stays the same
HEAT, WORK & INTERNAL ENERGY
• The increase in the internal energy of the system is equal to the amount of energy added by heating the system minus
the amount lost as a result of the work done by the system on its surroundings
∆E = q – w
E=internal energy
q=heat absorb by the system
w=work done by the system
ENTALPHY
• Enthalpy (H) is a measure of the total energy of a thermodynamic system.
• +∆H indicates that heat is being absorbed in the reaction (it gets cold)→ ENDOTHERMIC
• -∆H indicates that heat is being given off in the reaction (it gets hot)→EXOTHERMIC
Endothermic reaction
The reactants have less potential energy than do the products.
Energy must be input in order to raise the particles up to the higher energy level.
Non-spontaneous : process occurs with an input of energy
Exothermic reaction
The reactants have more potential energy than the products have.
The extra energy is released to the surroundings.
Spontaneous : process occurs without input of energy
2nd LAW THERMODYNAMIC
• When energy is converted from one form to another (energy available to do work) is degraded into a less-usable form
(heat) that disperses into the environment.
• Expresses concept that events in universe have direction
• Systems tend to proceed from ordered to disordered states
The 2nd law is about the direction which the process can take place and the ‘quality’ of the energy
2|Page
