Zusammenfassung der Ressource
Biological molecules
- Carbohydrates
- Lipids
- Can exist as fats, oils and waxes
- Made up of C,H and O
- Vast majority are Triglycerides
- roles of triglycerides
- Energy reserves
- electrical insulation eg. myelin in nerve cells
- Thermal insulation eg.blubber
- Metabolic source of water eg. in camels
- waterproofing eg. the waxy cuticle in plant leaves
- structure of
triglycerides
- Three fatty acid molecules
combine with one glycerol
molecule
- fatty acids have a Carboxyl group(COOH)
- Triglycerides are bad
conductors and have no
charge
- Cholesterol-is also a lipid but is not a triglyceride
- Made up of 4 carbon rings
- Found in cell membranes
- It's hydrophobic nature allows it to sit between the Phospholipid tails within the
cell membrane
- So it can work to regulate fluidity and strength of the membrane
- Water
- structure
- One oxygen atom covalently bonded to two hydrogen atoms
- oxygen atoms have slight negative charge and
hydrogen atoms have slight positive charge,
therefore water is a polar molecule
- other polar molecules( e.g. salts,glucose, amino acids) will disolve in water,
but non-polar molecules are insoluble in water.
- Roles
- Plays an important role in the blood,
lymphatic,excretory and digestive
systems, as it is very good at
transportation due to being a solvent
- properties
- Thermal properties
- High specific heat capacity-means aquatic species are more able to adapt to a
stable environment
- This means lots of heat is needed to make water evaporate from the body, so sweating is
very effective at cooling us down
- Density and freezing properties
- solid from less dense than liquid form (so large
bodies of water don't often freeze )
- High density is also
used for support and
protection e.g.
Amniotic fluid in the
womb
- cohesion and surface tension
- Cohesion occurs because
hydrogen bonds pull water
molecules in at the surface
- Cohesion is responsible for
surface tension-allowing small
organisms to walk on water
- Proteins
- Structure
- long chains of amino acids
- central
Carbon atom
attached to
four groups
- Amino group-NH
- Amnio groups are basic-alkaline in water
- Hydrogen atom-H
- R group-varies between amino acids
- Carboxyl group- COOH
- Carboxyl groups are acidic
- Anything with alkaline and acidic regions is amphoteric,
meaning it can resist tendency to change its PH, therefore
amino acids are amphoteric
- There are 20 amino acids, all of
which plants produce, however
animals only produce 12 and so
they need to consume the other 8
- Two bonded amino acids=dipeptides
Multiple bonded amnio
acids=polypeptiedes.
- amino acids are held together by
polypeptide bonds
- Nucleic Acids
- Enzymes