cc1 - biological compounds Flashcards
four key inorganic ions in living organisms
magnesium ions
iron ions
calcium ions
phosphate ions
role of magnesium in plants
used to produce chlorophyll
role of iron in animals
found in haemoglobin + involved in transport of oxygen
role of phosphate in living organisms
produces ADP + ATP
role of calcium in living organisms
strengthens tissues like bones and teeth in animals + cell walls in plants
why is water a polar molecule
O is more electronegative than H
O attracts electron density in covalent bond more strongly
h bonding between water molecules
weak intermolecular forces of attraction form between lone pair on a O and a H on an adjacent molecule
metabolite
molecule formed or used in metabolic reactions
role of water as a metoblite
water is reactant in photosynthesis + hydrolysis reactions
water is product in aerobic respiration + condensation reactions
why is waters high specific heat capacity important for organisms
water acts as a temp buffer, enabling endotherms to resist fluctuations in core temp+ to maintain optimum enzyme activity
why is waters high latent heat of vaporisation important for organsims
when water evaporates, it has a cooling effect
important in homeostasis; organisms can lose heat through sweating + panting
why is water an important solvent for organisms
water is polar universal solvent
enables chem reactions to take place in cells, transport of materials in plasma, + removal of metabolic waste
why does water have high surface tension
due to ordered arrangement + cohesion of molecules at surface of water
why is high surface tension of water important for organsims
enables transport of water + nutrients through plant stems and small blood vessels in body
allows small insects to ‘walk’ on water
monosaccharide
simple sugar
general formula - Cn(H20)n
examples of monosaccharides
ribose
deoxyribose
alpha + beta glucose
fructose
galactose
bond between two monosaccharides
glycosidic bond
disaccharide
molecule formed by condensation of 2 monosaccharides, forming glycosidic bond
formula - C12H22O11
examples of disaccharides + their monosaccharide constituents
sucrose (glucose-fructose)
maltose (a-glucose-a-glucose)
lactose (glucose-galactose(
polysaccharide
polymer of monosaccharides
formed by many condensation reactions
examples of polysaccharides
starch
glycogen
cellulose
chitin
function of starch
energy storage in plants
structure of starch
polymer of a-glucose monomers
two forms: amylose + amylopectin
amylose: a-1,4-glycosidic bonds, unbranched
amylopectin: a-1,4- and a-1,6- glycosidic bonds, branched
function of glycogen
energy storage in animals
structure of glycogen
highly branched - enables rapid hydrolysis of glucose molecules
structure + function of cellulose
linear polysaccharide - main component of cell walk in plants
consists of many b-glucose molecules joined by b-1,4-glycosidic bonds
alternate glucose materials rotated 180° allowing H bonds between parallel chains, forming myofibrils
structure + function of chitin
linear polysaccharide found in exoskeleton of insects + crustaceans as well as fungal cell walls
consists of many b-glucose molecules (w/ amino acid side chains) joined by b-1,4-glycosidic bonds
alternate glucose molecules rotated 180° allowing H bonds between parallel chains, forming myofibrils
how a triglyceride is formed
one molecule of glycerol forms ester bonds w/ 3 fatty acids via condensation reactions
structure + function of triglycerides
high energy to mass ratio - energy storage, high calorific value from oxidation
insoluble hydrocarbon chain - no effect on water potential of cells, used for waterproofing
slow heat conductor - thermal insulation, e.g: adipose tussue
less dense than water - buoyancy if aquatic animals
phospholipid
formed by condensation of 1 molecule of glycerol, 2 molecules of fatty acid + a phosphate group
structure + function of phospholipids
glycerol backbone attached to 2 hydrophobic fatty acid tails + 1 hydrophilic polar phosphate head
forms phospholipid bilayer in water - component of cell membranes
tails splay outwards - waterproofing, e.g: skin
diff between saturated + unsaturated fats
saturated fats - no C double bonds, solid at room temp due to strong intermolecular forces
unsaturated fats - one of more C double bonds, liquid at room temp due to weak intermolecular forces
diff between monounsaturated fats + polyunsaturated fats
monounsaturated fats - contain one C double bond
polyunsaturated fats - contain more than one C double bond
low density lipoprotein
combination of triglycerides from saturated fats + protein
block receptor sites, reducing cholesterol absorption
bad
how ldls contribute to risk of cardiovascular disease
high blood cholesterol level caused by ldls lead to formation of atherosclerosis plaques
general structure of amino acids
amine group (-NH2)
variable side chain (R)
carboxyl group (-COOH)
H atom
how polypeptides form
many amino acid monomers join together in condensation reactions
forms peptide bonds
primary structure of a protein
individual sequence of amino acids
secondary structure of protein
local interactions of amino acids in polypeptide chain resulting in a-helices or b-pleated sheets
h bonds
tertiary structure of protein
folding of protein to make 3d structure
disulfide bonds
ionic bonds
h bonds
hydrophobic interactions
quaternary structure of protein
interactions of more than 1 polypeptide chain
may involve addition of prosthetic groups, e.g: metal ions or phosphate groups
structure + function of fibrous proteins
long polypeptide chains, folded in parallel
little tertiary/quaternary structure aside from cross linkages for strength
- makes then insoluble + good for structural roles
structure + function of globular proteins
spherical, compact, highly folded w/ complex tertiary/quaternary structures
hydrophilic r groups face out + hydrophobic r groups face in - water soluble
metabolic roles, e.g: enzymes
diff between reducing + non reducing sugar
reducing sugar - free aldehyde or ketone functional group so can act as reducing agent
non reducing sugar - no free aldehyde or ketone functional group so cant act as reducing agent
benedicts for reducing sugar
add equal volume of sample being tested + benedicts reagent
heat in electric water bath at 100°C for 5 mins
observe colour of precipitate formed
+ive result for reducing sugars
colour change from green to yellow to orange to brown to brick red depending on quantity of reducing sugar present
benedicts for non reducing suagr
+ive test for reducing sugar
hydrolyse non reducing sugars w/ equal vol of dilute HCl
heat in boiling water bath for 5 min
retest solution w/ benedicts reagent
observe colour of precipitate formed
+ive result for non reducing sugars
colour change from green to yellow to orange to brown to brick red depending on quantity of non reducing sugar present
food test used to identify proteins
buiret
biuret test
add equal volume of sample + NaOH
add few drops of dilute copper sulfate solution
mix + record observations
+ive result of biuret
colour change from pale blue to purple
iodide test for starch
add iodine-Kl solution
colour change from organe to blue-black if +ive
emulsion test from fats + oils
add ethanol to sample + shake
allow to settle
add equal volume of water
record observations
+ive result of emulsion test
white cloudy emulsion forms
