contain carbon,
hydrogen and oxygen
in a 1:2:1 ratio
Monosaccharides
Simple sugars
contains 3 to seven
carbon atoms
isomers have the
same molecular
formula but a different
arrangement in space
Disaccharides and
Polysaccharides
2 simple sugars
joined together are
disaccharides
condensation reactions occur
to join simple sugars together
to form dissaccharides and
polysaccharides, it requires the
removal of a water molecule
di and polysaccharides
have to be hydrolysed
before the energy
stored in the simple
sugars can be used
polysaccharides
are more than 2
simple sugars
joined together
Lipids 1:2 ratio
they contain carbon to
hydrogen in the ratio 1:2,
they also contain oxygen.
most
lipids are
insoluble
lipids are an
important energy
storage providing
double that of
carbohydrates
when there are
excess lipids
they are stored
as fat reserves
Fatty Acids
long carbon chains with hydrogen atoms attached
one end of the chain is a carboxyl group
the carboxyl group is the only part of the molecule that reacts with water as it is the only hydrophilic part of the molecule
saturated fatty acids have no double carbon carbon bonds there is complete saturation of hydrogen atoms
unsaturated fatty acids have double carbon carbon bonds
monounsaturated means there is only one double bonds
polyunsaturated means there are multiple double bonds
Eicosanoids
lipids derived from
arachidonic acid - a fatty
acid that must be
absorbed in the diet as it
can't be made in the body
Leukotrienes are produced
mainly by cells that coordinate
responses to injury and disease
Prostaglandins are short
chain fatty acids that
have a ring of 5 carbons.
They are
released by cells
to coordinate
local cellular
activities
local hormones, they only effect
the area they are released in
Glycerides
fatty acids
are joined to
a backbone
of glycerol
the number of fatty acids
determines whether it is a
mono, di or tri glyceride
Energy Source - they can be broken down into their parts to provide energy
Insulation - fat deposits under the
surface of the skin act as insulation
Protection - a fat deposit around an organ provides a cushion against trauma
Phospholipids
and Glycolipids
A phospholipid is a
diglyeride that is
attached to a
nonlipid group by a
phosphate group
A glycolipid is
a carbohydrate
attached to a
diglyceride
the heads of both
are hydrophilic and
the tails hydrophobic
so a micelle forms
A bylayer can be formed
to make the membrane
of a cell, it is mostly
made of phospholipids
Steriods
large lipid molecules that share a distinctive carbon framework
the bits that make them different are the different groups that attach to them
the plasma membrane contains cholesterol which is needed to maintain the plasma membrane
steriod hormones are involved in sexual function
steriod hormones are important in the regulation of tissue metabolism and mineral balance
derivatives called bile salts are required for the processing of dietary fats
Proteins are formed from amino acids
Types
Structural - create a 3D framework for the body
Contractile - responsible for muscle contraction
Transport - molecules that can't travel in the blood are transported by a transport protein
Buffering - provide a buffering system to stop pH change in the blood
Enzymes - accelerate metabolic reactions
Hormones - influence the actions of every cell in the body or specific organs/organ systems
Defense - tough waterproof proteins to protect against the outside environment and antibodies to protect against disease
Protein Structure
long chains of amino acids
There are 20 differnt amino acids that make up all the proteins in the body
Amino Acids
central carbon atom
hydrogen atom
amino group
carboxyl group
R group
The R group is what maes each amino acid differnt and changes the function of the amino acid
water soluble
form peptide bonds with each other
Protein Shape
Primary structure - sequence of amino acids in a single polypeptide
Secondary structure - formation os a simple 3D shape, a helix or a pleated sheet
Tertiary structure - the secondary structure bends and folds around itself and forms a complex 3D shape uses various bonds to keep its position. The strongest bond is the disulphide bond.
Quaternary structure - tertiary structures bonding with each other to form a protein complex
Fibrous and Globular proteins
Fibrous - extended sheets are strands. Tough, durable, insoluble and structural
Globular - compact, rounded and only function when in an aqueous solution
Portein Shape and Function
shape determines function
shape depends on the order of amino acids
local environmental conditions can effect the shape of proteins e.g. pH can break bonds
Enzyme function
reactants in enzyme reactions are substrates
the active site is specific to certain substrates and weak bonds form between the 2 to help the reaction happen
how it happens
1 - the substrates bond to the active site
2 - the substrates are then bonded together in the enyzme substrate complex
3 - the binding of the substrates changes the shape of the active site
4 - the enzyme releases the product and starts all over again
Characteristics
Specificity - enzymes can only catalyze specific reactions because of their unique active sties. There are multiple enzymes that can catalyze the same reaction that are called isozymes.
Saturation limits - the rate of reaction is limited by the concentration of both enzyme and substrate. The higher the concentration the higher the chance of a successsful collison and reaction taking place.
Regulation - enzymes are effected by changes in the environment so the cell can change them to alter whether the enzyme is active or inactive
Cofactors and Enzyme Function
cofactor - ion or molecule that must bind to the enzyme before the substrate can
cofactors alter the shape of the active site
Coenzymes - nonproteins organic molecules that act as cofactors
Temperature and pH on enzyme action
optimum conditions exist for enzymes and if the conditions stay far from the set point then the enzyme will stop working and in extreme conditions will denature
denature - an irriversable change in the structure of an enzyme that means it no longer functions
Glycoproteins and Proteoglycans
combinations of proteins and carbohydrates
glycoproteins - large proteins with small carbohydrate groups
GPs are antiobdies, enzymes, hormones or protein components of blood plasma
glycoproteins in plasma membranes identify normal and abnormal cells and start the immune response
GPs also secrete mucins that absorb water to become mucus
Proteoglycans are polysaccharides linked to polypeptides
DNA and RNA
nucleic acids - organic
molecules made up of
carbon, hydrogen, oxygen,
nitrogen and phosphorus
DNA is the building blocks to life
they code for everything in the
body and all the characteristics
that make people different
RNA is used to copy DNA so the
information stored on the DNA
can be used to make proteins
Structure of Nucleic acids
Nucleotides -
pentose sugar,
phosphate
group and
nitrogenous
base
the pentose sugar is
either ribose (RNA) or
deoxyribose (DNA)
the 5 bases
T - thymine
A - adenine
G - guanine
C - cytosine
U - uracil
A and G are
purines - double
ringed molecules
T, C and U are
pyrimidines - single
ringed molecules
T is only found in DNA
and U only in RNA
The phosphate group
and sugar form the
backbone of the DNA
(the sides of the ladder)
The bases form the
rungs of the ladder with
A and T bonding and C
and G bonding only
RNA and DNA
RNA is a
single chain of
nucleotides
there are 3 types of RNA:
mRNA - messenger, tRNA -
transfer, rRNA - ribosomal
DNA is a double strand of
nucleotides held together
with hydrogen bonds
Complementary base pairs
are the only pairs that occur
A and T(or U), C and G.
ATP
ATP can be broken down
to ADP and then AMP
releasing energy each time
high energy
compound
the attachment of a phosphate
group on to another molecule
is called phosphorylation
ATP is made up of adenine
bonded to ribose which is then
bonded to a chain of 3 phosphates