1 Biological Molecules: 2 Nucleic Acids Flashcards
What is water?
A major component of cells.
Why is water dipolar?
Oxygen atom has a slight negative charge whilst hydrogen atoms have a slight positive charge.
What is the importance of water in metabolism?
It’s a metabolite in many metabolic reactions including condensation and hydrolysis reactions.
Chemical reactions take place in an aqueous medium.
A major raw material in photosynthesis.
What is the importance of water in solvents?
Water readily dissolves other substances: gases such as oxygen and carbon dioxide, wastes such as ammonia and urea, inorganic ions and small hydrophilic molecules such as amino acids and monosaccharides and ATP.
Enzymatic reactions take place in solution.
What is water’s importance in relation to its specific heat capacity?
It has a relatively high heat capacity, buffering changes in temperature.
Because water molecules stick together due to hydrogen bonding, it takes more energy to separate and heat them.
Without hydrogen bonds, water would be a gas at rtp.
What is water’s importance in relation to its latent heat?
It has a relatively large latent heat of vaporisation, providing a cooling effect with little loss of water through evaporation.
This makes sweating an effective cooling mechanism.
What is water’s importance in relation to its cohesion?
There is strong cohesion between water molecules.
This supports columns of water in the tube-like transport cells of plants.
A surface tension is produced where water meets air.
Where are inorganic ions normally?
In solution in the cytoplasm and body fluids of organisms.
Some are in high concentrations, others in very low concentrations.
What does DNA do?
Hold genetic information.
What does RNA do?
Transfer genetic information from DNA to the ribosomes.
What are ribosomes formed from?
RNA and proteins.
What is a nucleotide composed of?
A pentose sugar, a nitrogenous organic base, and a phosphate group.
What are the components of a DNA nucleotide?
Deoxyribose, a phosphate group, and one of the organic bases adenine, thymine, cytosine or guanine.
What are the components of a RNA nucleotide?
Ribose, a phosphate group, and one of the organic bases adenine, uracil, cytosine or guanine.
What does the condensation reaction between two nucleotides form?
A phosphodiester bond.