IB Biology HL 2025
A1.1
* Water- started cooling down
* Became a solvent so that other organisms could dissolve in it
* And these macromolecules could self-replicate
* Phospholipids formed and then arranged themselves in the form of MICELLES with
es
amphipathic properties
ot
N
IB
* Thermal buffer- because it has high specific heat capacity-provided stable conditions
* Solvent properties
* Metabolite
* Ionic and Covalent Compounds
s'
* Ionic- charged- formed ions and then come together
* Non polar- no charge
at
* Polar-charged relationship- H2O- electronegativity of o is greater than that of H+ some have
partial charges
* When water molecule combines with another molecule of water- partial charge of hydrogen
combines with partial charge of oxygen- so its not a ionic compound
N
* This causes surface tension on
* Non- polar relationship- h2,n2 etc.
Water-
Specific heat capacity- the heat needed to raise a substance's temperature by 1˚C
More heat is required to overcome intermolecular forces and
Water is a very good solvent
Thats why many metabolic processes take place there
Water molecules are polar which is why it’s easy for compounds to dissolve in it
, +ve ions can react with -ve O2 and -ve ions can react with +ve H2
Oil is hydrophobic because it is completely covalent and does not mix with water
Water (H2O)- have covalent bonds
But two water molecules have ephemeral (temporary) attractions which have a hydrogen bond
They keep attaching and detaching
Because of delta(∂) +ve H and ∂ -ve O
Water is a polar molecule- bc one side is +ve and one side is -ve
Non-polar- neutral charges so they aren’t attracted to each other when you put 2 non-polar
es
molecules together
ot
N
IB
s'
Co- to itself
at
Ad- to something else
The water stick to each other because of cohesion and they are able to move upwards due to
adhesion to the xylem
N
Hydrophilic- polar- water loving
H is ∂+ so it is attracted to the -ve Cl atom
O is ∂- so it’s attracted to the +ve Na atom
Hydrophobic- non-polar- water hating
Is a good solvent because of HYDROGEN BONDS and POLARITY
A1.1
* Water- started cooling down
* Became a solvent so that other organisms could dissolve in it
* And these macromolecules could self-replicate
* Phospholipids formed and then arranged themselves in the form of MICELLES with
es
amphipathic properties
ot
N
IB
* Thermal buffer- because it has high specific heat capacity-provided stable conditions
* Solvent properties
* Metabolite
* Ionic and Covalent Compounds
s'
* Ionic- charged- formed ions and then come together
* Non polar- no charge
at
* Polar-charged relationship- H2O- electronegativity of o is greater than that of H+ some have
partial charges
* When water molecule combines with another molecule of water- partial charge of hydrogen
combines with partial charge of oxygen- so its not a ionic compound
N
* This causes surface tension on
* Non- polar relationship- h2,n2 etc.
Water-
Specific heat capacity- the heat needed to raise a substance's temperature by 1˚C
More heat is required to overcome intermolecular forces and
Water is a very good solvent
Thats why many metabolic processes take place there
Water molecules are polar which is why it’s easy for compounds to dissolve in it
, +ve ions can react with -ve O2 and -ve ions can react with +ve H2
Oil is hydrophobic because it is completely covalent and does not mix with water
Water (H2O)- have covalent bonds
But two water molecules have ephemeral (temporary) attractions which have a hydrogen bond
They keep attaching and detaching
Because of delta(∂) +ve H and ∂ -ve O
Water is a polar molecule- bc one side is +ve and one side is -ve
Non-polar- neutral charges so they aren’t attracted to each other when you put 2 non-polar
es
molecules together
ot
N
IB
s'
Co- to itself
at
Ad- to something else
The water stick to each other because of cohesion and they are able to move upwards due to
adhesion to the xylem
N
Hydrophilic- polar- water loving
H is ∂+ so it is attracted to the -ve Cl atom
O is ∂- so it’s attracted to the +ve Na atom
Hydrophobic- non-polar- water hating
Is a good solvent because of HYDROGEN BONDS and POLARITY
