Biology
CH OH
O OH
H H H
H
Unit 1 OH OH
sydr | 2025
, Molecules, transport and health
1A. Chemistry for biologists
• Ionic bonding: bonds formed when atoms give or receive electrons.
Key: Ions
represents electron
Anion-negative ion Cation- positive ion
Important anions:
- Nitrate ions (NO ) needed in plants to make dna panino aids and proteins.
- Phosphate ions (PO ) needed to nake atp and ADP.
- Chloride ions (Cl ) needed in ner ve impulses, sweating and many secretary
systems in animals.
- Hydrogencarbonate ions (HCO ) needed to buffer blood pH.
Important cations:
- Sodium ions (Na ) needed in ner ve impulses, sweating and many
secretory systems in animals.
- Calcium ions (Ca ) needed for the formation of calcium pectate, bone
formation and muscle contraction.
- Hydrogen ions (H ) needed in cellular respiration and photosynthesis
- Magnesium ions (Mg ) needed for production t chlorophyll in plants.
• Covalent bonding: bonds formed when atoms share electrons.
Dipole - separation of charge in a molecule when the
electrons in covalent bonds are not evenly shared
sydr | 2025
,• Hydrogen bonding: leak electrostatic intermolecular bonds formed
bet ween pola molecules containing at least one Hydrogen atom
H H O
Hydrogen bond
O
H H
Dipoles
H
H
O
Dissociation - splitting of a moleccele into smaller molecules, atoms, o ions,
especially by reversible process.
Water is:
Adhesion- different molecules
- Polar solvent.
attract each other.
- Excellent transport solvent.
- Reaches max density at 4 C.
- Has high specific heat
capacity.
- Cannot be compressed.
- Water molecules are cohesive Cohesion - like molecules
and adhesive. attract each other
- Water has high surface
tension.
In water:
Adhesion Cohesion
sydr | 2025
, 1A. Carbonhydrates
Organic compound that contain oxygen, hydrogen and carbon.
Monomer - small molecule that is a single unit of a larger molecule.
Polymer - long-chain molecule made up of many smaller repeating
monomer units joined together by chemical bonds.
Monomer
Polymer
Monomer Polymer
Monosacharide Carbonhydrate
Fatty acid Lipid
Nucleotide Nucleic acid
Amino acid Protein
Carbon hydrates function: energy source, storing energy sport of cell
walls in plants s fungi and bacteria.
Monosaccharides: simple sugars. (CH O)
• triose sugars. (C H O )
• pentose sugars. (C H O )
• hexose sugars. (C H O )
CH OH CH OH O OH CH OH
H O H H O OH
H H H H H H
ОH H ОH H
HO OH HO H
OH OH OH
H OH H
Glucose Ribose sydr | 2025
Glucose
CH OH
O OH
H H H
H
Unit 1 OH OH
sydr | 2025
, Molecules, transport and health
1A. Chemistry for biologists
• Ionic bonding: bonds formed when atoms give or receive electrons.
Key: Ions
represents electron
Anion-negative ion Cation- positive ion
Important anions:
- Nitrate ions (NO ) needed in plants to make dna panino aids and proteins.
- Phosphate ions (PO ) needed to nake atp and ADP.
- Chloride ions (Cl ) needed in ner ve impulses, sweating and many secretary
systems in animals.
- Hydrogencarbonate ions (HCO ) needed to buffer blood pH.
Important cations:
- Sodium ions (Na ) needed in ner ve impulses, sweating and many
secretory systems in animals.
- Calcium ions (Ca ) needed for the formation of calcium pectate, bone
formation and muscle contraction.
- Hydrogen ions (H ) needed in cellular respiration and photosynthesis
- Magnesium ions (Mg ) needed for production t chlorophyll in plants.
• Covalent bonding: bonds formed when atoms share electrons.
Dipole - separation of charge in a molecule when the
electrons in covalent bonds are not evenly shared
sydr | 2025
,• Hydrogen bonding: leak electrostatic intermolecular bonds formed
bet ween pola molecules containing at least one Hydrogen atom
H H O
Hydrogen bond
O
H H
Dipoles
H
H
O
Dissociation - splitting of a moleccele into smaller molecules, atoms, o ions,
especially by reversible process.
Water is:
Adhesion- different molecules
- Polar solvent.
attract each other.
- Excellent transport solvent.
- Reaches max density at 4 C.
- Has high specific heat
capacity.
- Cannot be compressed.
- Water molecules are cohesive Cohesion - like molecules
and adhesive. attract each other
- Water has high surface
tension.
In water:
Adhesion Cohesion
sydr | 2025
, 1A. Carbonhydrates
Organic compound that contain oxygen, hydrogen and carbon.
Monomer - small molecule that is a single unit of a larger molecule.
Polymer - long-chain molecule made up of many smaller repeating
monomer units joined together by chemical bonds.
Monomer
Polymer
Monomer Polymer
Monosacharide Carbonhydrate
Fatty acid Lipid
Nucleotide Nucleic acid
Amino acid Protein
Carbon hydrates function: energy source, storing energy sport of cell
walls in plants s fungi and bacteria.
Monosaccharides: simple sugars. (CH O)
• triose sugars. (C H O )
• pentose sugars. (C H O )
• hexose sugars. (C H O )
CH OH CH OH O OH CH OH
H O H H O OH
H H H H H H
ОH H ОH H
HO OH HO H
OH OH OH
H OH H
Glucose Ribose sydr | 2025
Glucose
