A1.1 Water Flashcards
What are the different roles of water
Universal solvent
metabolite
temperature buffer
maintaining biological structures
explain waters role as a universal solvent
-helps multicellular organisms transport molecules around the body
-medium for chemical reactions to occur
explain waters role as a metabolite
water is either a reactant or a product in metabolic reactions
explain waters role as a temperature buffer
metabolic reactions are catalysed by enzymes, because enzymes are sensitive to temp, reactions can only occur within a certain temperature.
Water acts as a buffer due to high specific heat capacity
explain waters role in maintaining biological structures
-contributes to the formation of cell membranes
-impacts the folding of proteins
-surrounds DNA to support the double helix
what are atoms made up of
protons, neutrons and electrons
what are ions
atoms that have deficit or a surplus of electrons
what are cations
ions that have lost electrons and have a positive charge
what are anions
ions that have gained electrons and have a negative charge
how are atoms able to form bonds
electrons may be transferred to other nearby atoms or shared between atoms
what is the purpose of bonds
they enable the formation of chemical compounds
what are the different types of bonds
-non polar covalent bonds
- polar covalent bond
- ionic bond
-hydrogen bond
what are non polar covalent bonds
they share electrons equally
what are polar covalent bonds
they share electrons unequally
what happens when one atom has more mass than the other atom in the bond
the electrons that are being shared will be pulled towards the heavier atom and one side will be slightly positive and one side will be slightly negative
what is an ionic bond
an attraction between a positively charged ion and a negatively charged ion
what are polar molecules
are molecules where one end is slightly positive while the other is slightly negative
what are hydrogen bonds
an attraction between 2 polar molecules
one slightly positive and one slightly negative
how are hydrogen bonds represented
with a dotted line
what is the structure of water
consists of 2 hydrogen and 1 oxygen that are connected with polar covalent bonds
how many bonds can water molecules form
upto 4
what is cohesion
waters ability to make hydrogen bonds with itself cause water molecules to stick together
what is surface tension
the property of the surface of liquid that allows it to resist an external force, due to the cohesive nature of its molecule
what does hydrophilic mean
polar and charged molecules are hydrophilic because they attract water
what is adhesion
the force of attraction between different types of molecules or substances,
- caused by the unequal sharing of electrons in polar molecules
what is capillary action
the movement of water in through a narrow space, often in opposition to external forces like gravity
how does soil retain water
due to adhesion, water sticks to the soil particles
what are solvents
the liquid in which a solute dissolves to create a solution
what happens when solutes dissolve
their molecules separate from each other and become surrounded by water molecules
this is known as a “hydrogen shell”
what happens to polar molecules in water
they will dissolve because they are hydrophilic and can form hydrogen bonds
what happens to charged ions in water
they will dissolve because they are electrostatically attached to water
what happens to non polar molecules in water
they wont dissolve because they are insoluble and will clump together
why is water needed for cellular metabolism
because it dissolves the reactants and enzymes so they can come together for reactions
what happens to lipids during transportation
they are coated in phospholipids to form a structure called a “lipoprotein”
what is a physical property
a measurable behaviour or characteristic of matter that exists without the matter reaction or interacting with other things
what is buoyancy
an upward force applied to an object that is immersed in a fluid
what happens if the buoyant force of the fluid is greater than the objects weight
the object will float
what is buoyancy affected by
the density of the object
how are birds adapted to float
they have hollow bones with struts to strengthen them and make them less dense
how are bony fish adapted
they have a swim bladder that can fill or lose gas to change densities
what is viscosity
the measure of a fluids tendency to flow
- due to the amount of friction the molecules of a liquid experience as they flow over each other
what does it mean by more viscous and less viscous
more viscous means theres less movement
less viscous means more movement
how do hydrogen bonds affect viscosity
they increase the friction making water more viscous than other substances
how do solutes affect viscosity
cells and dissolved solutes increase viscosity
what is thermal conductivity
the measure of a materials ability to move heat across a temperature gradient
- is determined by how easily energy transfers through the material
what is specific heat capacity
the quantity of heat needed to raise the temperature of a chemical per unit mass
how is waters high specific heat capacity an advantages
-good for temperature regulation
-body temperatures rise and fall slowly in response to external changes in temperature
-creates a stable environment
how does water compare to air
higher
-buoyant force
-viscosity
-thermal conductivity
-specific heat capacity
how are ringed seals adapted to their environment
-is buoyant
-is streamlined
-insulated with blubber
-due to high SHC of water, there is a stable environment
How are black throated loons adapted to their environment
-buoyant
-air has bad thermal conductivity so not much loss of body heat but air temperature changes more often
where is water believed to have come from
from asteroids and coments which contained large amounts of water
why can water stay on earth
right distance from sun and gravity stops it from escaping
why is water a precedent to extraterrestrial life
because its vital to life
