2.1 molecular biology

Question 1

define metabolism

Answer 1

the totality of all enzyme-catalyzed reactions in a cell or organism

Question 2

compare anabolism vs catabolism

Answer 2

anabolism: the build up of complex molecules from more simple subunits (monomers)

requires condensation reaction to proceed (water is produced as a by-product)

example: photosynthesis

catabolism: the breakdown of complex molecules into more simple subunits (monomers)

requires hydrolysis reaction to proceed
(water is consumed as part of the reaction)

example: cell respiration

Question 3

differentiate between organic and inorganic compounds

Answer 3

organic molecules contain carbon and are synthesized by living organisms

exceptions include carbonates, carbides, oxydes of carbon and cyanides

Question 4

explain how the structure of carbon atom contributes to the formation of organic life

Answer 4

carbon forms the basis of organic life due to its ability to form large and complex molecules via covalent bonding

carbon atoms can form 4 covalent bonds allowing a diversity of stable compounds to exist

Question 5

explain the theory of vitalism and how it was falsified

Answer 5

vitalism proposed that organic molecules could only be synthesized by living organisms

it was falsified by Frederick Woehler in 1828

He was able to synthesize urea (an organic molecule) from an inorganic salt in an artificial way

Question 6

define monomer

Answer 6

a recurring subunit that forms a complex macromolecule

Question 7

compare the 4 different types of bio macromolecules

Answer 7

carbohydrates:
monomer/subunit- monosaccharide
polymer- polysaccharide
bond involved- glycosidic linkage

lipid:
monomer/subunit- glycerol + 3fattyacids
polymer- triglyceride
bond involved- ester linkage

protein:
monomer/subunit- amino acid
polymer- polypeptide
bond involved- peptide bond

nucleic acid
monomer/subunit- nucleotide
polymer- DNA or RNA
bond involved- phosphodiester bond

Question 8

write the chemical formula for an unsaturated fatty acid

Answer 8

CH3 - (CH2)n - COOH

Question 9

draw molecular diagrams of glucose and ribose

Answer 9

check paper

Question 10

explain how the following may be identified based on their chemical formula

Answer 10

carbohydrate: C H O and H O have a ration of 2:1

protein: C H O N (S) may contain sulphur (some amino acids include sulphur)

nucleic acid: will contain phosphorus in relatively large amounts (nucleotides include a phosphate group