A1.1- water Flashcards
water are the four reasons water is important
water is a solvent, water is a metabolite, water provides optimum temp for enzymes, maintains biological strucutres
explain importance of water as a solvent
has ability to dissolve molecules thus transport them around organisms acting as a medium in which chemical reactions happen in
explain importance of water as a metabolite
in chemical reactions in cells water either is the reactant or product
condensation- water product
hydrolysis- water reactant
explain importance of water providing optimum ph
in metabolic reactions which uses enzymes, they need optimum temperatures which water provides
water has a high specific heat capacity thus can stay liquid for long
explain importance of water maintaining biological structures
contributes to formation of cell membrane (phospholipid heads interact with water, phospholipid tail avoids water, this makes protein fold into shape needed to perform function)
surrounds DNA to support double helix (needed to follow instructions encoded DNA or pass instructions into future cells)
how did the solar system form
when a cloud of gas and dust collapsed into a swirling disk; some of the cloud was water
why liquid water could not be found in early inner solar system
young sun intense heat prevented water vapour from condensing
what is the main hypothesis for origin of water on earth
tiny grains of dust acted as condensation nuclei, let droplets form particles coalesced into young planet along with water carried when earth cooled rocks in crust reacted with chemicals in earths atmosphere to create more water molecules; water existed inside earth mantle but not as individual h2o molecules but as oh or simply h
most of water was imported from asteroids or comets, beleived that jupiter was closer to the sun and its gravity caused millions of asteroids to be pushed towards earth
what is evidence that asteroids and comets provided water to earth
every h2o molecule, a fraction of it has a hydrogen atom which has an extra neutron in nucleus
water from a comet vs asteroid has different ratios of these heavy hydrogen atoms and when comparing this with normal water, the waters atomic fingerprint is more closely related to that of an asteroid thus majority of water came from asteroids not comets
what does goldilock zone mean
habitable zone where it has just right distance from a star for water to remain at least periodically in loquid form on surface, earth orbits sun just right distance for water to remain lqiuid thus in goldilock zone
explain mars relationship to goldilock zone
mars is in the goldilock zone however it is too small to keep an atmosphere which is needed to sustain life
what are the circumstances for life to be present in a planet
luck- having all right chemicals at same place same time
time- evolution is complex took billions of years
location- not too hot or too cold to have liquid water on surface
chemicals- water
functions as solvent allowing key chemical reactions to take place, heat conduction, surface tension and high specific heat capacity
chemicals- carbon
simple building block that organisms need to form organic compounds eg, protein carbs and lipids
chemicals- phosphorus
key component of ATP molecule provides energy to drive and support many processes in living cells
chemicals- nitrogen
needed to make amino acids
chemicals- sulphur
part of many biochemical processes on earth most enzymes cant function without
what 2 characteristics support retention fo water
distance of earth from sun keeps temp below water vaproisation, water is able to stay liquid or ice from due to cohesion of water molecules via h2 bonds
earths gravity keeps water from escaping planet
name of equipment that explores planet surface
rover
location on earth with similiar H:N ratio as asteroids
oceans
waters property to sustain life
solvent
name of bond between O and H
polar covalent bonds
charges of O and H
O= -
H= +
water molecules polar or non polar
polar
polar meaning
hydrophilic molecule
water loving
non polar meaning
hydrophobic molecule
water fear
name of bond between different H2O molecules
hydrogen bonding