water + hydrogen bonds Flashcards
Describe the strength of hydrogen bonds (2)
Individual hydrogen bonds are weak;
However, collectively together they are very strong
Where are hydrogen bonds commonly found? (4)
Proteins;
Water;
DNA;
tRNA
How does hydrogen bonding occur between water molecules? (2)
Water is a polar molecule due to uneven distribution of charge;
Bond forms between the delta positive hydrogen atom and the delta negative oxygen atom
What are the properties of water? (4)
Important solvent in reactions;
A transport medium;
A coolant;
Provides a habitat for aquatic organisms
Describe how the properties of water make it suitable as a habitat for living organisms (4)
- Water buffers temperature;
- So therefore, provides a stable internal environment;
- Cohesion between water molecules;
- Which enables small invertebrates to live on water surface
Describe how properties relating to the density of water contribute to the survival of organisms in a habitat (3)
Ice is less dense than water so floats;
Floating ice on the surface of water acts as an insulator for organisms living in the water;
Ice will provide a habitat for some species
Describe how the properties of water make it suitable as a coolant (4)
Water has a high specific heat capacity and a high latent heat of vaporisation;
This is due to the strong hydrogen bonds between the molecules;
Internal temperatures within plants and animals remain constant in external fluctuating temperatures;
As it provides a cooling effect in animals via sweating and a cooling effect in plants via the transpiration stream
Describe how the properties of water make it suitable as a transport medium (2)
Cohesion between water molecules;
Forms a continuous column of water in the xylem of plants
Describe how the properties of water make it suitable as a solvent (3)
Polar molecules dissolve readily in water;
Due to water being polar;
Which causes attraction to the solute molecules (the polar molecules)
What is one eukaryote and one prokaryote example of water acting as a solvent? (2)
In bacteria, water acts as a solvent for nutrients and ions for biochemical reactions;
In human cells, water dissolves glucose and oxygen for respiration
What is one eukaryote and one prokaryote example of water acting as a transport medium? (2)
In cyanobacteria, water helps transport dissolved gases like CO2 for photosynthesis.;
In plants, water transports nutrients and minerals through the xylem from roots to leaves.
What is one eukaryote and one prokaryote example of water acting as a coolant? (2)
In thermophilic bacteria, water helps dissipate heat generated from metabolic reactions.;
In humans, sweating allows water to evaporate from the skin, cooling the body.
What is one eukaryote and one prokaryote example of water acting as a habitat? (2)
Water serves as a habitat for aquatic bacteria, providing a stable environment for growth and reproduction;
Water bodies serve as habitats for fish and amphibians, supporting a wide range of life forms.
