biology
Structural Isomers
• molecules with the same molecular formula but with different arrangements of atoms
• differences in the shape of isomers lead to differences in their physical & chemical properties
• For example, galactose, glucose and fructose have the same molecular formula (C₆H₁₂O₆) but different structures (figure 6 page 30)
• glucose itself has 3 different structural isomers
in dry state, glucose has a linear structure, but when dissolved in water, the molecules fold on itself to form one of the two possible ring structures: α-glucose (alpha) β-glucose(beta)
two isomers of glucose differ only in the orientation of a single hydroxyl (-OH) group
small structural differences lead to large differences in chemical properties
starch found in mushrooms (amylopectin) is a polymer of α-glucose – can easily be digested STARCH = DIGESTIBLE
Cellulose found in celery is a polymer of β-glucose – cannot be easily digested by most animals CELLULOSE – NOT DIGESTIBLE
• Isomers illustrate that structure of a molecule determines the function of that molecule
STRUCTURE = FUNCTION
The Molecule of life
• Most molecules of living organisms are composed of thousands of atom. these molecules are considered macromolecules
• Macromolecules are subdivided into polymers and monomers
• polymers: are long chain-like substances made of many smaller molecules linked together by a covalent bond
• monomers: smaller molecules covalently bonded which can link to make polymers
• the molecules associated with living things are grouped into 4 major categories
carbohydrates
lipids (fats)
proteins
nucleic acids
1. Carbohydrates
• it’s a biological macromolecule that consists of carbon, hydrogen & oxygen in a 1:2:1 ratio
• are among the most common organic material on earth
• millions of tonnes are produced by plants and algae every year through the process of photosynthesis
• are used by organisms as a source of energy,
• molecules with the same molecular formula but with different arrangements of atoms
• differences in the shape of isomers lead to differences in their physical & chemical properties
• For example, galactose, glucose and fructose have the same molecular formula (C₆H₁₂O₆) but different structures (figure 6 page 30)
• glucose itself has 3 different structural isomers
in dry state, glucose has a linear structure, but when dissolved in water, the molecules fold on itself to form one of the two possible ring structures: α-glucose (alpha) β-glucose(beta)
two isomers of glucose differ only in the orientation of a single hydroxyl (-OH) group
small structural differences lead to large differences in chemical properties
starch found in mushrooms (amylopectin) is a polymer of α-glucose – can easily be digested STARCH = DIGESTIBLE
Cellulose found in celery is a polymer of β-glucose – cannot be easily digested by most animals CELLULOSE – NOT DIGESTIBLE
• Isomers illustrate that structure of a molecule determines the function of that molecule
STRUCTURE = FUNCTION
The Molecule of life
• Most molecules of living organisms are composed of thousands of atom. these molecules are considered macromolecules
• Macromolecules are subdivided into polymers and monomers
• polymers: are long chain-like substances made of many smaller molecules linked together by a covalent bond
• monomers: smaller molecules covalently bonded which can link to make polymers
• the molecules associated with living things are grouped into 4 major categories
carbohydrates
lipids (fats)
proteins
nucleic acids
1. Carbohydrates
• it’s a biological macromolecule that consists of carbon, hydrogen & oxygen in a 1:2:1 ratio
• are among the most common organic material on earth
• millions of tonnes are produced by plants and algae every year through the process of photosynthesis
• are used by organisms as a source of energy,