1 Flashcards
(28 cards)
Water is a … in lots of important chemical reactions, including hydrolysis reactions
reactant
Water is a …, meaning some substances dissolve in it
solvent
Most biological reactions take place in … so water is essential.
solution
Water transports substances. The fact that it’s a liquid and a solvent means it can easily transport all sorts of materials, like … and oxygen around plants and animals.
glucose
Water helps with … control because it has a high specific heat capacity and a high latent heat of evaporation.
temperature
Water is a … The fact that it helps with temperature control, is a solvent and becomes less dense when it freezes means many organisms can survive and reproduce in it.
habitat
A molecule of water (H2O) is one atom of oxygen joined by two atoms of hydrogen by shared …
electrons
Because the negative hydrogen electrons are pulled towards the oxygen atom, the other side of each hydrogen atom is left with a slight … charge.
negative
A polar molecule has a partial … charge on one side and a partial positive charge on the other.
negative
The unshared negative electrons on the oxygen atom give it a partial … charge on one side and a partial positive charge on the other.
negative
The slightly negatively-charged oxygen atoms attract the slightly positively-charged atoms of other water molecules. This attraction is called … bonding.
hydrogen
Hydrogen bonds give water a high … … … - the energy needed to raise the temperature of 1 gram of a substance by 1C.
specific heat capacity
The hydrogen bonds between water molecules can absorb a lot of …
energy
Water has a high specific heat capacity meaning it takes a lot of energy to … it up.
heat
Because water has a high specific heat capacity, it doesn’t experience rapid temperature changes, which is one of the reasons it makes a great habitat, the temperature under water is likely to be more … than it is on land.
stable
It takes a lot of energy to break the hydrogen bonds between water molecules. So water has a high latent heat of … - a lot of energy is used up when water evaporates.
evaporation
A high latent heat of evaporation is useful in living organsims because it can … things, for example, when sweat evaporates it cools the surface of the skin.
cool
Cohesion is the attraction between molecules of the … type.
same
Water molecules are very … because they’re polar.
cohesive
Because water is very …, it helps water to flow, making it great for transporting substances.
cohesive
Cohesion helps water to be transported up plant stems in the … stream.
transpiration
At low temperatures water freezes - it turns from a liquid to a solid. Water molecules are held further apart in ice than they are in liquid because each water molecule forms four hydrogen bonds to other molecules, making a … shape.
lattice
Because of the lattice shape ice is less dense than liquid water - which is why ice …
floats
Ice floating is useful for organisms because in cold temperatures, ice forms an … layer on top of water, as the water below doesn’t freeze.
insulating
