Water Flashcards
Name the ion needed for formation of proteins
Sulfate
Name the ion involved in the transport of gases by the blood
Clorine
Name the ion essential for photosynthesis
Magnesium
Name the ion that a lack could disrupt nervous coordination of the body.
Calcium, Sodium or Potassium
What is cohesion?
water attracted to water
What is adhesion?
water attracted to other objects
What is described here? (Sharing of electrons for full outer shells)
Covalent bonds
Describe covalent bonds
Sharing of electrons for full outer shells
Water is described as being polar. What does this mean?
Oxygen is slightly negatively charged whilst hydrogen atoms are slightly positively charged
Is water polar or non-polar?
Polar
What atoms are present in a water molecule?
2 atoms of hydrogen and one atom of oxygen
What bonds exist between water molecules?
Hydrogen bonds
Describe why water has hydrogen bonding
The slightly negative oxygen of one water molecule attracts the slightly positive hydrogen atoms of other water molecules
What does high specific heat capacity measure/mean?
The amount of energy needed to raise the temperature of a fixed amount of that substance by 1*C. A lot of heat energy is required to raise water’s temperature
Describe why water has a high specific heat capacity.
New hydrogen bonds are formed almost as quickly as the are disrupted. Because heat energy from the sun is used up breaking and re-forming hydrogen bonds, the water temperature doesn’t increase by much.
What’s he significance for life of water having a high specific heat capacity?
Conditions are stable in cells and aquatic environments.
Why is water considered being an Universal Solvent?
The unequal distribution of electrical charge makes water a good solvent for many substances.
What molecules WILL dissolve in water?
Ionic substances like salt and polar molecules such as sugar and amino acids
What molecules WILL NOT dissolve in water?
non-polar molecules such as lipids
Describe the advantage of ice being less dense than water
This forms an insulating layer over the surface of aquatic habitats: ponds and other aquatic habitats don’t freeze solid so animals can still move/swim.
Does water’s density (mass per unit volume) increase or decrease when it freezes?
Decrease because water expands when it freezes
Why will ice float on top of water?
Ice is less dense than water
Describe water’s high latent heat of vaporisation.
A lot of energy is needed to evaporate water so organisms use water evaporation to cool down, sweating. Also aquatic habitats don’t disappear easily by evaporation.
What is the effect of transpiration on leaves?
Cooling effect
Why is water being transparent beneficial?
Light can pass through for aquatic plants to photosynthesise under water.
Light can pass through he cytoplasm of plant cells so it can reach the chloroplast.
How is water having a high surface tension beneficial for life?
At the air/water interface of a pond, the cohesion between water molecules produces surface tension. This acts as a skin that covers the water almost and forms a habitat on the surface of the water, for example pond skater.
What would be the property of water being used in biochemical reactions, for example photosynthesis.
Water is a metabolite
What is the significance for life (plants and animals) of water being liquid at most temperatures?
It can be used as a transport medium eg. blood in mammals and it dissolves ions up xylem in plants. Also medium for reactions.
What is the significance of water having strong cohesive properties and high tensile strength?
Water can be pulled through plants in a column as the water molecules are held together by hydrogen bonds.
