Summary IB Biology chapter 2: MOLECULAR BIOLOGY

MOLECULAR BIOLOGY


Carbohydrates
● Made up of carbon, hydrogen and oxygen
● Short term energy storage
● Monomer = monosaccharides (single sugars)
● Monosaccharides → disaccharides → polysaccharides
● Glycosidic bonds
Monosaccharides
1. Glucose
2. Fructose
3. Galactose
4. Ribose
Disaccharides
1. Glucose + glucose → maltose + water
2. Glucose + galactose → lactose + water
3. Glucose + fructose → sucrose + water
Polysaccharides
1. Starch
2. Glycogen
3. Chitin
4. Cellulose

Lipids
● Made up of carbon, hydrogen and oxygen
● Long term energy storage
● Monomer = fatty acids, glycerol, phosphate groups
● Ester bonds

, 3 types
1. Phospholipids = 2 fatty acids + glycerol + 2 H2O
2. Triglyceride = 3 fatty acids + glycerol + 3 H2O
3. Steroids = 4 hydrocarbon rings

Proteins
● Made up of carbon, hydrogen, oxygen, nitrogen and phosphorus
● Monomer = amino acids (polypeptide chain)
● Peptide bonds

Nucleic acids
● Made up of carbon, hydrogen, nitrogen and phosphorus
● Monomer = nucleotides (polynucleotide chains)
● Phosphate ester bonds

Anabolism
● Synthesis of complex large molecules from smaller molecules
● Macromolecules/polymers from monomers
● Loss of water
● Uses energy (endergonic)
● Condensation reaction

Catabolism
● Synthesis of small molecules from larger ones (breaking down)
● Addition of water
● Hydrolysis reaction

Metabolism
● Web of all enzyme catalyzed reactions that occur in a cell or
organism
1. Source of energy
2. Synthesis of new materials