Water and Inorganic Ions Flashcards
why is water dipolar?
it has an unevenly distributed charge due to the oxygen being slightly negative and the hydrogen being slightly positive
what bonds form between the water molecules between the H and the O?
hydrogen bonds
how is water a metabolite?
It’s used in many reactions
-approximately 90% of the plasma in the blood is water
-cytoplasm in cells is mainly water too
how is water a good solvent?
polar molecules dissolve in water because it’s dipolar, they’re hydrophilic
- positive hydrogen atoms attract negative solutes
- negative oxygen atoms attract positive solutes
what does it mean when water has a high specific heat capacity?
a lot of energy is required to raise the temperature of water by breaking the H bonds
- temperature of water remains stable for enzymes to work optimally
what does it mean when water has a large latent heat of vaporisation?
a lot of energy is required to convert water into a gas
- heat energy from the skin is transferred to the water to evaporate it
- provides a cooling effect (eg. sweating)
- due to H bonds needing to be broken
why is the fact that water is cohesive and advantage?
water molecules stick together to produce a continuous column of water up the xylem
-easier to draw up a column rather than individual molecules
provides surface tension to water
-allows smaller animals to move and live on the surface away from predators
what bonds form between the O and H within a water molecule?
covalent
where do inorganic ions occur in an organism?
the cytoplasm
what is ATP composed of?
3 phosphate ions, a ribose molecule and an adenine molecule
why is ATP a good source of energy?
- releases energy in small manageable amounts so none is wasted
- small and soluble so can be easily transported around the cytoplasm
- only 1 bond is broken to release energy immediately
- energy can be transferred to another molecule by transferring a Pi group (phosphorylation - making other compounds more reactive)
- can’t pass out the cell so the cell always has a supply of energy
why is the phosphate group described as inorganic?
because it doesn’t contain carbon
how is ATP made?
- in respiration
- from ADP by adding a Pi via a condensation reaction using ATP synthase
how is ATP hydrolysed?
by removing water using the enzyme ATP hydrolase