biological molecules (water) Flashcards
define polar
where there is an electrostatic charge in a region of an molecule
why is water polar
as the oxygen that forms has a stronger electrostatic bond to the shared pair of electrons so therefore becomes delta negative and the hydrogen becomes delta positive
what bonds does water form
hydrogen bonds
are hydrogen bonds weak or strong
hydrogen bonds are only individually weak but in large numbers are strong
what is specific heat capacity
the amount of energy required to raise the temperature of a substance
why is specific heat capacity important
specific heat capacity means the temperature of water doesn’t fluctuate much
why does water have a high specific heat capacity
the hydrogen bonds need to be broken for the molecules to move around therefore it requires more energy
why does ice float
the ice has expanded meaning the hydrogen bonds have formed further away creating an open structure which is not dense at all
what is cohesion
cohesion is where water atoms are attracted to each other due to hydrogen bonds being formed
what is adhesion
adhesion is where water molecules are attracted to other materials
what is surface tension
created by cohesion it means there is a structure of hydrogen bonds which can have pressure applied before breaking
why is water used as a solvent
water is an extremely polar molecule meaning it can dissolve many polar substances like proteins and ions
why is water used for metabolic reactions
it can dissolve substances therefore act as a medium for chemical reactions
why is water used as a transport medium
due to cohesion and adhesion mean they are attracted to each other and the surfaces so can move around as a group easily
what is a capillary action
water can go against gravity due to adhesion and cohesion
