Water 11/09/15 Flashcards
% of water in a plant cell
90%
What is the structure of water
Hydrogen bonds O-H-O
Shown by (——)
Slightly negative oxygen
Slightly positive hydrogen.
Why is the oxygen nucleus stronger?
It has a bigger mass
Ionic bonding of hydrogen and oxygen
Each hydrogen shares a pair of electrons with an oxygen. Oxygen has a greater affinity for electrons than hydrogen so pulls the electrons in closer/
What is a polar molecule
A molecule with an uneven distribution of charge
How would you describe water in terms of charge?
Overall neutral but polarised with charged.
How is a hydrogen bond formed
Water is able to bond easily with other water molecules, as the oxygen and hydrogen atoms are polarised.
How strong is a hydrogen bond?
Individually weak, constantly being broken down and reformed.
Loads of bonds make a stable structure.
Adjacent
Why is water a good solvent?
It’s dipole, the water molecules create a layer around the ions and break the ionic substance apart.
COVALENTLY BONDER MOLECULES EG GLUCOSE AND AMINO ACIDS CAN DISSOLVE
Why are lipids insoluble?
Because they are not polar, they don’t attract water molecules which is important for cell membranes.
High specific capacity
Oceans have a non- fluctuating temperature
Temperature buffer for smaller organisms
Water is a coolant
Sweat- takes heat
Plants, calling via transpiration.
Ice is less dense than water.
Floats: Kinetic energy decreases as the temperature decreases when ice is formed
4 hydrogen bonds in ice
3 hydrogen in water
ICE= lattice
Thermal insulator
Cohesion
Long columns of water molecules don’t break because of the hydrogen bonds. (Drawn up xylem)
Surface tension- skin. Pond skaters.
Metabolite
Cellular reactions.
Condensation
Hydrolysis
Transparent
Allows light for photosynthesis
