biochem Flashcards
def of matter
everything around us
has mass
occupies space
def of atoms
small particles of matter
what is an element made of
1 type of atom
how many elements in body
26
4 major elements in body
Carbon
Hydrogen
Oxygen
Nitrogen
protons charge
+
neutrons charge
0
electrons charge
-
location of protons
nucleus of atom
location of protons
nucleus of atom
location of electron
electron shell
mass of proton, electron, nrutron
proton 1
neutron 1
electron - no mass
what is a stable element
equal no of protons, neutrons, electrons
overall neutral charge
what does atomic no tell us about a neutral element
no of protons and neutrons
how do you work out the no of electrons from the mass no
mass no - atomic no = electron no
in periodic table mass or atomic no is always bigger
mass
C 6, 12, how many P, E, N
6 P & N, 6 E
H2, 3, how many P, E, N
2 P, 2 E, 1 N
Cl 35, 17 how many P, E, N
17 P & E, 18 N
atoms of same element with diff no.s of neutrons in nucleus are called
Isotopes
do Isotopes have same charge & mass
same charge
different mass
Why does Chlorine in periodic table have atomic mass of 35.5
is average of two isotopes
the bonding properties of an element depend on what
no. electrons in outer shell
electron shells like to be full!
process of giving/gaining electrons is
ionisation
removal of electrons is
oxidation
what happens to potential energy in oxidation
decreased
most oxidation is a removal of
hydrogen
removal of H is what reaction
dehydrogenation
gaining electrons is what
reduction reduced
what happens to energy in reduction
increased
If a molecule gains H it is usually what
reduced
oxidation + reduction is what reaction
redox reaction
what are free raducals
molecules/compounds with unpaired electron in outer shell
how to free radicals cause damage
cause oxidation as steal other electrons, leaving other molecules with unpaired electrons - a chain reaction of oxidative damage
where do free radicals come from
aerobic respiration inflammation X rays smoking alcohol etc
how do chain-breaking antioxidants work
by donating electrons to free radicals, converting them to harmless molecules
4 ex chain-breaking antioxidants
Vit A, E
Betacarotene
Glutathione
2 main types of bond
Electrocovalance/ionic (electron donation)
Covalent (electron sharing)
Electron pulling power is known as
electronegativity
2 electro-negative elements
oxygen
nitrogen
what are polar bonds
electronegative element joins with a different element
pulls electrons toward them
uneven charge
what type of bonds do hydrophilic molecules have
polar - dissolve easily in water (alcohol)
what type of bonds do hydrophobic molecules have
non-polar covalent - don’t dissolve
fats
what is an electrolyte
ionic compound dissolved in a solution
3 reasons why electrolytes are important to the body
conduction of electricity essential for nerve/muscle function
exert osmotic pressure, essential for water balance
can act as pH buffers
what is an acid
substance that releases H+ ions in solution
what is a base
substance binds to H ions in a solution creating OH-
H+ low pH
Acid
OH- high pH
base
how is acidity measured
by no of Hydrogen ions in a solution
what pH is water
neutral
pH 7
Acid + Base =
salt + water
how do buffers work
some bind to H+
others bind to OH-
prevent damaging changes in pH
Is energy ever lost
no. will only change state
where is chemical energy stored
in bonds between atoms
4 states of matter
solid
liquid
gas
plasma
solid shape/volume
definite shape and volume
liquid shape/volume
definite volume, shape of container
gases shape/volume
indefinite shape/volume
solid particles
fixed
close together
vibrate
liquid particles
mobile
close together
move slowly
gases particles
far apart
move fast
changes of state occur with
addition of energy
chemical reactions, starting materials:
reactants
chemical reactions end products:
products
how does endothermic reaction work
takes in heat
uses heat for energy
how does exothermic reaction work
releases heat
what is energy of activation
min. temp. req. for chemical reaction
how does catalyst work
speeds up reactions by lowering activation energy
what act antagonistically to catalysts
inhibitors
anabolic reactions do what
build up
take in heat
endothermic
catabolic reactions do what
breakdown
release heat/energy
exothermic
when water catabolises molecule it is what reaction
hydrolysis reaction
when water is a waste product of a reaction its a
dehydration synthesis reaction
when synthesis and decomposition in same reaction it is a
exchange reaction
are some chemical reactions also reversible
yes
