Water Flashcards
Draw hydrogen bonding
H+
-
O-
-
H+How does the density of the water decreasing to temperatures before 4c, so ice floats on top, help organisms survive in ponds?
Density of the water decreases when it turns to ice as the particles are arranged further apart in a lattice shape, allowing the ice to float on top and it acts as insulating layer. Allowing it t keep a regular temperature. and organisms can carry on moving
How does water acting as a solvent for ions (nitrates) help organisms survive?
By water being a solvent it allows for substances to be dissolved in it as the positive water molecules attract to the negtive ions and vise versa , allowing the water to completely surround it; making a solvent. Therefore,this allows for the plants and animals to uptake the nutrients in the water- need nitrates for amino acids
How does water being able to need lots of energy to raise the temperature by 1c, help organisms survive?
The hydrogen bonds need a lot of energy to break apart as they absorb lots, therefore has a high specific heat capacity. Meaning the temperature stays quite stabl, meaning the organisms have a stable environment and there is no effect on the enymes for eg.
What type of reaction occurs when water is added to break a bond in a molecule
Hydrolysis
The phosphate group of a phospholipid that readily attracts water molecules
Hydrophilic
Why is water vital to living organisms?
- Reactant
- Solvent
- Transports substances
- Controls temperature
- Habitat
What is cohesion?
Why are water molecules cohesive?
The attraction between molecules of the same type
Water molecules are very cohesive because they are polar
Describe a water molecule
One oxygen molecule attached to two hydrogen atoms. They share electrons therefore the negative hydrogen electrons are pulled forward on the hydrogen, leaving them with a slight positive charge. And negative on the oxygen from the unshared electrons. This makes water polar
High specific heat capacity
The hydrogen bonds can absorb lots of energy, therefore can keep a stable environment for the organisms.
Useful as many cells are water
How is water a solvent
Substances are mainly ionic, therefore the positive electrons attract to the negative polar electrons of the water and vise versa. Therefore the ions become completely surrounded by the water molecules and dissolve.
Water has a high latent heat of evaporation
This means it takes a lot of energy to break the hydrogen bonds between the water molecules. So lots of energy is used up when water is evaporated. This is useful for cooling organisms.
What reactions does water take place in?
Photosynthesis and hydrolysis reactions
Why is water being a solvent important?
Most biological reactions take place in solutions making it pretty essential
What substances does water transport
Glucose and oxygen around plants and animals
Why is water important at controlling temperatures?
Helps cools surfaces and lower the temperature
Water is a small molecule much lighter than co2 but remains a liquid at room temp, why?
Due to the hydrogen bonding between the water molecules, it takes alot of energy to increase the temperature of water and cause it to change states into a gas
What happens when water freezes?
When water freezes the hydrogen bonds fix positions of the polar molecules slightly further apart than the average distance. This make a giant rigid lattice structure with oxygen at the center of the arrangement
resulting into the ice floating
Start to solidify and hydrogen bonds in the water molecules form crystal infrastructure which space molecules apart more evenly, making it less dense
Cohesive properties in organisms
As water cohesive, they attract to eachother, therefore plants can draw up water by their roots and up xylem tissues of plants
what and how is water got adhesive properties
This is where water molecules are attracted to other molecules as they have more charge. an example is washing your hands, the water doesnt run straight off.
A property of cohesion and pros of it
Surface tension as the water molecules are more cohesive to each other than anything else around
This allows the top of water to be a habitat for ponskaters
Why is water an important transport medium
it can dissolve many molecules
At what temperature does the density of water start to decrease
4c
Difference between adhesion and cohesion
A- attraction between two different molecules
C- acttraction between two of the same molecules
Why dont hydrophobic molecules dissolve in water?
They have no polar charge and being pushed out of the water be waters cohesiveness
