Biological Molecules 3

DNA

holds genetic information

RNA

transfers genetic information from DNA to the ribosmes

DNA nucleotide

deoxyribose, a phosphate group and a base

RNA nucleotide

ribose, a phosphate group and a base

Phosphodiester bond

condensation between two nucleotides

DNA base pairing

A=T, G≡C

RNA base pairing

A=U, G≡C

DNA molecule

long double helix chain with two antiparallel polynucleotide chain held together by hydrogen bonds between specific complementary base pairs

RNA molecule

single stranded short polynucleotide chain

Semi-conservative replication

ensures genetic continuity between generations of cells

Process of DNA replication

DNA helicase break hydrogen bond between bases to unwind the double helix

exposed base on template strands attract and pair complementery to free nucleotides

DNA polymerase joins adjacent nucleotides by condensation, forming phosphodiester bond

ATP molecule

a molecule of ribose, adenine and three phosphate group

ATP hydrolase

catalyse hydrolysis of ATP to ADP and an inorganic phosphate group to release energy

ATP synthase

catalyse condensation of ADP and inorganic phosphate to produce ATP during respiration

Solubility of water

polar due to hydrogen bonds

charged end attracted to opposite charged ion, causing the water molecule get totally surrounded by ions, means dissolved

High latent heat of vaporisation

lots of heat is used to change waer from liquid to gas

sweating carries a lot of heat energy when evaporates to lower body temperature

High specific heat capacity

takes a lot of heat energy to heat up

maintain a constant internal body temperature

very cohesive

supports columns of water in xylem in plants and produce surface tension when it meets air

Iron ions

bind to oxygen in haemoglobin

Sodium ions

for co-transport of glucose

Phosphate ions

components of DNA and ATP