Biological molecules

Created by

Angela Mathi

Cards (95)

Potassium (K+)
Balance electrical, osmotic gradient
Co-transport
Protein synthesis
Cell sap
Name 5 roles of water
It is a reactant in lots of chemical reactions
It is a solvent
It transports substances
It helps with temperature control
It is a habitat
Describe the structure of a water molecule
One atom of oxygen with a lone pair of electrons
Two atoms of hydrogen
What makes water polar?
It has a partially negative charge on oxygen and a partially positive side on the hydrogen, as oxygen is highly electronegative
What is hydrogen bonding?
The lone pair on the oxygen atoms attract the partially positive hydrogen atoms of other molecules
What is specific heat capacity?
The amount of energy needed to raise the temperature of 1 gram of a substance by 1 degree celsius
How do hydrogen bonds give water a high specific heat capacity? 
The hydrogen bonds between water molecules can absorb a lot of energy, so it takes a lot of energy to heat up the water
How does having a high specific heat capacity make water a good habitat?
It means that the water does not experience rapid temperature changes
Why does water have a high latent heat of evaporation?
It Takes a lot of energy to break the hydrogen bonds between water molecules, so a lot of energy is used up when it evaporates
Why is it useful that water has a high latent heat of evaporation for living organisms?
It means that water is great for cooling things, for example, some mammals sweat when they are hot to cool the surface of the skin
What is cohesion?
The attraction between molecules of the same type
Why are water molecules very cohesive?
they are polar
What are the advantages of water being cohesive?
It helps water flow, making it great for transporting substances
It helps water be transported up plant stems in the transpiration stream
Acts like a skin for small organisms - surface tension
Why is water a good solvent?
it is polar, the slightly positive end will be attracted to the negative ion, and the slightly negative end will be attracted to the positive ion
This means that it will get totally surrounded by water molecules and dissolve
Why is water less dense as a solid than a liquid?
Water molecules are held further apart in ice than they are in water because each water molecule forms four hydrogen bonds to other water molecules, making a lattice shape
Why is it useful that ice floats on water?
In cold temperatures, ice forms an insulating layer on top of water and so the water below does not freeze.
Water in metabolism
Hydrolysis
Aqueous medium of chemical reactions
Raw material for photosynthesis
Water as a solvent
Readily dissolves substances for transport, waste removal, secretions
Water as a lubricant
Water with certain proteins make good lubricants like mucus for external movement and to reduce friction
Water giving support
Not easily compressed, so used in, hydrostatic skeleton of animals, amniotic fluid for foetus
Transparent
Organisms in aquatic environment can photosynthesise
Nitrate (NO3-)
in many different types of proteins like hormones, amino acids
Phosphate (PO4 3-)
used in phosphorylation of sugars in respiration, bone and teeth, cell membranes (phospholipids)
Calcium (Ca 2+) 
Cell walls
Translocation
Bone, teeth and shells
Clotting
Muscle contraction
Sodium (Na2+)
Balance electrical, osmotic gradient
Co-transport
Protein synthesis
Cell sap
Chloride (Cl-)
Balance electric and osmotic gradient
Form HCl
Chloride shift
Magnesium (2+)
Chlorophyll
Bones and teeth
Iron (Fe 2+ or Fe 3+)
Electron carriers
chlorophyll
Haemoglobin
What are the monomers that make up carbohydrates?
monosaccharides
How many carbon atoms does glucose have?
6 - hexose monosaccharide
What is the difference between alpha and beta glucose?
Alpha glucose hydroxyl group on c1 is down
Beta glucose hydroxyl group on c1 is up
What is the function of glucose?
It is the main energy source in animals and plants, due to chemical energy stored in bonds
Why can glucose easily be transported?
It is soluble
How many carbon atoms does ribose have?
5 - pentose monosaccharide
What elements are in carbohydrates?
carbon, hydrogen, oxygen
What is the ratio of carbon to hydrogen to oxygen in carbohydrates?
1 carbon : 2 hydrogen : 1 oxygen
How do monosaccharides join together?
By creating glycosidic bonds (-o-) via condensation
What is a condensation reaction?
a hydrogen atom on one monosaccharide bonds to an OH group on the other, releasing a molecule of water
What is a hydrolysis reaction?
When a molecule of water reacts with the glycosidic bond, breaking it apart
What is a disaccharide?
two monosaccharides joined together