Molecular Basis of Life
Living organisms have trillions of highly complex chemical
reactions happening every second. These take place in
the ______________.
Biochemistry – the study of the molecules and processes
involved in these reactions.
Molecule - ____________________________________
The 3 most important molecules are:
1. _____________________
2. _____________________
3. _____________________
Water (H2O)
 primary molecule of life
 carries molecules inside and outside of cell
 lubricant between tissues, organs and cells
Carbon (C) is a characteristic of living matter because:
i.
can form covalent bonds with 4 other molecules
C
ii. can form covalent bonds to other carbon atoms
(carbon skeleton)
- C–C–C–C–C–C–C–C–C–C–COrganic Compounds – molecules with both C & H
(H2O, O2, CO2 are all ________________ compounds.)
4 Main Organic Compounds are:
1.
2.
3.
4.
Carbohydrates
Lipids (Fats)
Proteins
Nucleic Acid (DNA & RNA)
1.
Carbohydrates (carbs)
carbo
hydro
a)
Why do we need carbohydrates?
i) source of energy (glucose) stored as:
- glycogen in animals
- starch in plants
ii) gives structure to plants (e.g. cell wall is cellulose)
iii) gives cell carbon skeletons (long string of carbon)
to build other molecules (e.g. fatty acids, amino acids)
b)
Types of Carbohydrates
i) Monosaccharides – simple sugars (pg 11, Fig 1.8)
one
sugar
- glucose
- fructose
- galactose
These are isomers, they have
the same # of atoms but are
configured differently
ii) Disaccharides – 2 simple sugars together (Fig 1.9)
two sugar
glucose + fructose = sucrose
glucose + galactose = lactose
glucose + glucose = maltose
iii) Polysaccharides – many simple sugars linked
together (Fig 1.10)
Starch – energy storage in ___________
Glycogen – energy storage in __________
Cellulose – energy storage in _____________
Exercise – using Lab Aids Kits, complete worksheet on
building carbohydrates. Answer all questions for
homework.