Biological Molecules

Question 1

Starch/glycogen

Answer 1

Storage – α glucose
Helical shape so compact
Insoluble molecule so osmotically inactive Branched so glucose is easily hydrolysed/added Large so cannot leave cell

Question 2

Cellulose

Answer 2

Structural molecule - β glucose
Long, unbranched chains of glucose
Joined by glyosidic bonds
Cellulose molecules hydrogen bonded together To form fibrils
Provides strength

Question 3

Structure of proteins

Answer 3

Polymer of amino acids
Joined by peptide bonds
Formed by condensation reaction
Primary structure is order of amino acids in the chain
Secondary structure is specific folding of primary structure held by hydrogen bonds
Tertiary structure specific folding secondary structure held by hydrogen bonds, ionic and disulfide bonds
Quaternary structure is made of two or more polypeptide chains.

Question 4

ATP

Answer 4

Consists of adenine, ribose and 3 phosphate groups Releases energy in small manageable amounts Hydrolysed in a one step
Energy available rapidly
Used to phosphorylates molecules Used to lower activation energy Reformed by adding phosphate to ADP