biomolecules Flashcards
monomer
smaller units of which larger molecules are made
polymer
many monomers bonded together
examples of monomers
glucose, amino acids, nucleotides
examples of polymers
starch, cellulose, glycogen, protein, DNA/RNA
condensation reaction
joining two molecules
creating chemical bond
removal of water
hydrolysis reaction
breaking chemical bond
between two molecules
using water
isomer
same molecular formula but different structure
disaccharide
made up of 2 monosaccharides
joined by glycosidic bonds
formed from condensation reaction
maltose
glucose+glucose
sucrose
glucose+fructose
lactose
glucose+galactose
starch structure
alpha glucose
made from 2 polymers:
amylose - unbranched helix joined by 1-4 gs bonds
amylopectin - branched helix joined by 1-4 and 1-6 gs bonds
starch structure related to function
compact to fit lots of glucose in small space
branched increasing surface area for rapid hydrolysis back to glucose
insoluble so wont affect water potential
cellulose structure
beta glucose
polymer formed of long straight chains using 1-4 gs bonds
held in parallel by many H bonds to form fibrils
cellulose structure related to function
many H bonds provide collective strength and rigidity
insoluble so it wont affect water potential
glycogen structure
highly branched involving 1-4 and 1-6 gs bonds
glycogen structure related to function
branched structure increases surface area for rapid hydrolysis back to glucose
insoluble so wont affect water potential.
whats meant by R group
variable group
saturated fatty acids
have the maximum number of hydrogen atoms possible and no double bonds in hydrocarbon chain
unsaturated fatty acids
have one or more double bonds in hydrocarbon chain
how are triglycerides formed
condensation of glycerol and 3 fatty acids
3 ester bonds form between each fatty acid and glycerol attaching to
it is not a polymer as its not many repeated units joining together
1 water is lost between each fatty acid (3 lost in total)
triglyceride structure
glycerol + 3 fatty acids
joined by ester bonds
triglycerides structure related to function
-large ratio of energy storing carbon-hydrogen bonds compared to number of carbons mean lots of energy can be stored
- high ratio of hydrogen to oxygen atoms allow it to act as a metabolic water source, releasing water if oxidised. important for desert animals e.g. camels
-large and hydrophobic, making them insoluble (not affecting WP)
- low mass, lots can be stored without increasing mass and preventing movement
how are phospholipids formed
2 condensation reactions between glycerol and fatty acids
2 ester bonds formed
1 condensation reaction between glycerol and phosphate group
1 phosphodiester bond formed
structure of phospholipids
hydrophilic head due to negative charge on phosphate group
attracts water and repels fats
hydrophobic tail is not charged
repels water and mixes with fats
properties of phospholipids
2 charged regions so is polar
in water its positioned so heads are exposed to water and tails are not
> forms phospholipid bilayer which makes up plasma membrane in cells
monomers in proteins
amino acids
dipeptide
Formed when two amino acids join together via condensation reaction
polypeptide
A polymer (chain) by condensation of many amino acids, are linked together by peptide bonds.
primary structure of protein
simple polypeptide chains and sequences of amino acids, determines its properties
secondary structure of protein
protein structure is formed by folding and twisting of amino acid chain into alpha helix or beta pleated sheet
tertiary structure
further bending and twisting forms a unique 3D shape
held in place by ionic, hydrogen and disulphide bonds
quaternary structure
protein made up of more than 1 polypeptide chain, e.g. haemoglobin
enzyme
tertiary structure proteins
which lower activation energy
of the reactions they catalyse
induced fit model
enzyme model where the substrate induces the enzyme to alter its shape
to mould around the substrate like a glove
to form an enzyme substrate complex
this puts strain on the bonds and lowers activation energy
temperature effect on enzymes
high temperature increases kinetic energy so more collisions between enzyme and substrate
works at an optimum temperature
if higher than optimum the enzymes denature, changing the shape of active site making the enzyme non functional and ES complexes cannot form
pH on enzymes
All enzymes work best at optimal pH. above and below the optimal pH the rate of reaction decreases. Extreme pH changes can denature the enzyme
effect of substrate and enzyme concentration on activity
insufficient substrate will slow down the reaction due to fewer collisions between enzyme and substrate
insufficient enzymes will cause active sites to be too saturated with substrate and unable to work any faster
competitive inhibitors
same shape as the substrate
binds to active site
prevents enzyme substrate complex
non competitive inhibitors
bind to allosteric site
causes active site to change shape
makes enzyme non functional, no ES complexes
test for starch
add iodine, turns from orange to blue/black
reducing sugar test
Add benedict’s solution and shake
Boil the test tube 80 deg C
If it goes orange/brick red: reducing sugar is present
test for non reducing sugars
Test for non-reducing sugar
Heat with Benedict’s
If negative (stays blue), hydrolyse substance with HCl and neutralise with NaOH. (or hydrolyse with an enzyme)
Heat with Benedict’s Brick red precipitate indicates non- reducing sugar.
test for lipids
Emulsion test, ethanol mixed with sample,
added to water,
milky white emulsion forms on top of the water
DNA nucleotode made up of
phosphate
, deoxyribose pentose sugar, nitrogenous base (either CGAT)
polynucleotide
A polymer consisting of many nucleotide monomers in a chain; nucleotides can be those of DNA or RNA.
condensation reaction between pentose sugar and phosphate
joined by phosphodiester bond
CG
AT
RNA vs DNA
much shorter
ribose vs. deoxyribose pentose sugar
single stranded vs. double stranded, uracil vs. thymine
RNA function
transfer genetic code from DNA in nucleus to ribosomes
Some RNA (rRNA) is combined with proteins to make ribosome
semi conservative replication
in each new DNA double helix, one strand is from the original molecule, and one strand is new
semi conservative replication steps
- DNA helicase breaks H bonds between complimentary base pairs, causing double helix to unzip and unwind
- strands act as a template, free floating nucleotides attract to their complementary base pairs on the template
- adjacent nucleotides join together by a condensation reaction catalysed by DNA polymerase
- two sets of daughter DNA contains one parental strand and one newly synthesised strand
forming atp
ADP +Pi condensation reaction
using ATP synthase
during respiration
breaking down ATP
ATP to ADP + Pi hydrolysis reaction
uses ATP hydrolase
releases small amount of energy
phosphorylation of glucose
ATP bonds with compound to make them more reactive
water properties
metabolite
solvent
high SHC
high latent heat of vaporization
strong cohesion
metabolite
involved in chemical reactions such as condensation and hydrolysis reactions
solvent
dipolar so can dissolve solutes and can easily transported around body in cytoplasm in cells
high SHC
Water requires a lot of energy to change temperature, good for preventing enzymes denaturing
high latent heat of vaporisation
Provides a cooling effect with little loss of water through evaporation
cohesion
strong cohesion supports water columns and provides surface tension in plants
importance of H ions
lower the pH of solutions
impact enzyme function
impact haemoglobin function OR
role in chemiosmosis
importance of iron ions
Component of haemoglobin in transporting oxygen
importance of sodium ions
involved in co-transport of glucose and amino acids in absorbption OR
role in generating action potentials
importance of phosphate ions
component of DNA which forms phosphodiester bonds with deoxyribose
ATP, making ADP more reactive
