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chemistry study, human bio, pe studies, quantitative vs qualitative…
chemistry study
covalent molecular substances
most molecular substances are insoluble or sparingly (slightly) soluble in ater
soluble in water
forms hydrogen bonds with water
ionise in water
covalent molecular compounds that form hydrogen bonds with water
some covalent molecular compounds can dissolve in water by forming hydrogen bonds with water
molecules that do this must be polar
for this to occur, the hydrogen bonds between the solute molecules break. the hydrogen bonds between the solvent molecules also break. then hydrogen bonds form between solute and solvent molecules.
the more polar a molecule is, the more likely it is to dissolve in water
for molecules that have a polar and non-polar section, the larger the non-polar section, the less soluble in water it is.
non-polar molecules do not have any charge so there is no significant attraction to water molecules. the weak dispersion forces are not enough to overcome the strong hydrogen bonding in water molecules. therefore these are not soluble in water
many organic compounds contain "OH" groups, also called hydroxyl groups. these are very polar
sugars and alcohols contain OH groups and are often soluble in water. the larger the non-polar section though, the less soluble they become
molecules that can ionise
some molecules are so polar that they "break" when the compound is placed in water
when HCl is added to water, the highly electronegative chlorine atom gives the hydrogen atom in HCl a slight positive charge. this hydrogen atom forms such a strong attraction to the oxygen in the water molecule tha the HCl covalent bond breaks.
when a molecules breaks into separate ions in water, it is ionised
the ions produced by this process are hydrated. the ions are surrounded by polar water molecules.
other molecules that ionise in water include acids like nitric acid (HNO3), sulphuric acid (H2SO4) and ethanoic acid (CH3COOH)
questions 15.4
ionic substances
consists of a metal and a non-metal
the metal donates its electrons to the non-metal
the metal atom that has lost electrons becomes a positively charged cation
ionic substances in water
when an ionic compound is added to water
the positive dipole of the hydrogen atoms in the water molecule is attracted to the negatively charged anion.
the negative dipole of the oxygen atom in the water molecule is attracted to the positively charged anion
this attraction between an ion and a polar molecule is called an ion-dipole attraction
if the ion-dipole attraction is strong enough, it pulls the ions out of the lattice structure and into solution
these ions then become surrounded by water molecules and are said to be hydrated
this process of a solid ionic compound separating into hydrated cations and anions is called dissociation
dissociation vs ionisation
dissociation of ionic compounds is the freeing of ions from the lattice so they can move freely through a solution
this is different to when covalent molecular substances undergo ionisation, because here new ions are forming from a reaction with water molecules
insoluble ionic substances
not all ionic substances are soluble in water
for some ionic compounds, the energy required to separate ions from the lattice is greater than the energy released when ions are hydrated
how do we know which ionic substances are soluble
the Snape rule. salts that contain one or more of the following ions are normally soluble
sodium (Na)
Nitrate (NO3)
Ammonium (NH4)
Potassium (K)
Ethanoate (CH3COO)
structure of water
covalent molecular
each oxygen atom shares one pair of electrons with 2 hydrogen atoms
V-shaped
each oxygen atom also has 2 non-bonding pairs of electrons
polar
the oxygen atom is more electronegative than the hydrogen atoms
hydrogen bonding
the molecule is polar, and consists of a hydrogen atom bonded to oxygen
hydrogen bonding
the intermolecular forces between the molecules in water are hydrogen bonds. these are the strongest of the intermolecular forces.
each water molecule can form hydrogen bonds with up to four other water molecules
high melting and boiling points
compared to other molecules of a similar size, water has high melting and boiling points
this is because a significant amount of energy is needed to disrupt all of the hydrogen bonds between water molecules
density in the liquid and solid states
when liquid water freezes, each molecule forms for hydrogen bonds to other water molecules
this results in water molecules in ice being more widely spaced than liquid water
when large bodies of water freeze , ice floats on top, insulating the water and preventing the entire body of water from freezing - allowing aquatic life to survive!
surface tension
surface tension is the measure of the resistance of a liquid to increasing its surface area.
water has high surface tension because the water molecules at the surface only form hydrogen bonds with molecules on the sides and below, not above
this means water molecules only spend about 1 nanosecond on the surface before being pulled downwards
heat capacity
the measure of a substance capacity to absorb and store heat energy it measures how much energy a substance absorbs as temperature increases.
specific heat capacity
measures the amount of energy (in joules) needed to increase the temperature of a certain amount (normally 1 gram) of that substance by 1c. its is expressed as joules per gram per degree celsius
specific heat capacity of water
water has a specific heat capacity of 4.18 g-1c-1. this means 4.18 joules are required to increase the temperature of 1 gram of water by 1c
this is relatively high because of the number and strength of the hydrogen bonds between water molecules
chromatography
used to separate and analyse the substances present in a mixture
components : the substances that are separated
chromatogram : the pattern that is formed
All methods of chromatography have
Stationary phase : the solid or liquid where materials are separated or selectively absorbed
mobile phase : the liquid or gas that moves the components to be separated over the stationary phase
chromatography measures the rate of movement of each component in a mixture.
the rate of movement depends on :
how strongly the component absorbs onto the stationary phase
both of these are dependent of the polarity of the components in the mixture, and the components used in the stationary and mobile phase
how readily the component dissolves in the mobile phase
paper chromatography
stationary phase: absorbent paper
applications: qualitative analysis of large amounts of non-corrosive polar compounds
Advantages: affordable
what is qualitative analysis
gives information to help identify the components present in a mixture - not work out how much of them there are.
to do this we need standards: known information about compounds that we sue to compare
we then calculate the retardation factor (Rf) of the sample and compare it with the known Rf values
What is the Rf value of the red component?
Step 1:
What is the distance the red component has travelled from the origin?
2 cm
What is the distance the solvent front has moved?
10 cm
Step 2:
Rf = distance of component from origin/distance of solvent from origin
Rf = 2/10 = 0.2
The Rf will always be a number less than 1.
The more strongly adsorbed onto the stationary phase a component is, the shorter distance it travels and therefore the smaller its RF.
thin layer chromatography
stationary phase: thin layer of fine powder (eg aluminium oxide or silica)
applications: qualitative analysis of less polar compounds, corrosive compounds and small amounts of sample. cannot be used for volatile compounds
advantages: wider choice of stationary phases
column chromatography
stationary phase: solid silica gel or aluminium oxide packed into a glass column
applications: used to remove impurities from mixtures and isolate different compounds
advantages: the ability to collect the different components
different components are eluted in different fractions, depending n how strongly they absorb to the stationary phase.
the liquid that leaves the column is called the eluent
high performance liquid chromatography
based off column chromatography, except the particles in the stationary phase are 10 - 20 times smaller.
this allows better separation of compounds
HPLC is used to detect the presence and concentration of components in a mixture.
stationary phase: same as column chromatography, but smaller
applications: to analyse the concentration of components in a mixture
advantages: can determine concentrations of components. only need small amounts of sample.
gas chromatography
the most sensitive chromatography technique
the mobile phase is an unreactive gas - called a carrier gas
stationary phase: is normally silica gel or alumina
Applications: calculating concentrations of components in a mixture
Advantages: need the smallest sample size
Arrhenius model
scientists like to classify things
acids and bases were originally classified in terms of taste, effect on an indicator and reactions with other substances
in 1887, Svante Arrhenius passed an electric current through various solutions, including acids and bases and his findings changed our understanding of acid base chemistry
Arrhenius model of acids
an acid is defined as a substance that is ionised in water to produce hydrogen ions
the hydrogen ions that are present in acid solutions account for the common properties of acids
monoprotic acid
hydrochloric acid and ethanoic acid are examples of monoprotic acids acids. this means they only form one hydrogen ion in solution
polyprotic acids
acids that can react with water to form more than one hydrogen ion are polyprotic acids
a diprotic acid forms forms 2 hydrogen ions
a triprotic acid forms 3 hydrogen ions
Arrhenius model of bases
a base is defined as a substance that dissociates in water to form hydroxide ions
some bases dissociate to form 1 hydroxide ion (Eg NaOH), others can form more than 1 hydroxide ion
electrolytes
an electrolyte is a substance that produces an electrically conducting solution when dissolved - due to the charge carrying particles that are present (ions)
both acids and bases produce ions in solutions that can conduct electricity
neutralisation reactions
when acids and bases react together, the hydrogen and hydroxide react to form water. this s called a neutralisation reaction
every reaction between acid and bases of equal amounts will end up with a salt and water
strong acids and bases
strong acids and bases completely ionise/dissociate in water to produce ions. this means there is no more of the original acid or base left - it all exists as ions
weak acids and bases
weak acids and bases also produce hydrogen ions and hydroxide ions in solution. but at any one time, only a small proportion of there compounds exists as ions
we represent weak acids/bases using double arrows, to show that the reaction is reversible
strong acids: HCl, H2SO4, HNO3
weak acids: H2SO3, H3PO4, HF, CH3COOH, H2CO3, Ammonium salt
strong bases: group 1 and group 2 Oxides and hydroxides
weak bases: metal phosphate, metal carbonates, metal hydrogen carbonates, ammonia
metallic bonding model
cations
positively charged ions
anions
negatively charged ions
delocalised electrons:
electrons that are not associated with a single atom or bond. these come from the valence shell of metallic atoms.
METALLIC BONDING MODEL
cations arranged in a closely packed 3D network
Electrons from the valence shell of the metal atoms are "lost" and delocalised
there is a strong electrostatic force of attraction between the cations and delocalised electrons
conducting electricity
in order for a substance to conduct electricity it needs to contain free moving charged particles
limitations
some properties of metals can not be explained using the metallic bonding model:
Range of melting points, hardness and densities of different metals
differences in electrical conductivities of metals
magnetic nature of metals
reactivity of metals and alloys
reactivity series of metals
the reactivity series of metals has been developed by chemists from experimental data of reactions
group 1 metals appear at the top of the series and transition metals appear at the bottom
reasons for different reactivities of metals
when metals react, their atoms tend to form positive ions by donating one or more of their valence electrons to other atoms.
the metal atoms that require less energy to remove electrons tend to be the most reactive - ie those with the largest atomic adii and lowest ionisation energy.
these are found in the bottom left hand corner of the periodic table
metals react with acids to form an ionic salt and hydrogen gas
metals react with oxygen to form an oxide
modifying metals
metals can be modified by:
alloy production
-heat treatment
formation of nano-sized structures
Alloys
A substance formed when a metal is mixed with carbon or other metal(s)
generally an alloy is harder and melts at a lower temperature than the pure metal because atoms of different sizes are now included in the metallic bonding lattice
Interstitial allow
a small proportion of an element with significantly smaller atoms is added to a metal. the added atoms sit in the very small spaces (interstices) between metal cations in the metallic lattice.
example: carbon steel is generally harder and less malleable that pure iron. varying the amount of carbon produces steels with different properties.
Substitutional alloy
an allow made from elements of similar chemical properties and size. these atoms are too big fit into the spaces in the metallic lattice so replace some of the iron cations.
examples: steels made from a mixtures of iron and manganese, chromium, nickel and cobalt.
metallic crystals
metals are made of a number of crystals which have boundaries between them. the malleability and brittleness depends on the size and arrangement of crystals
smaller crystals result in harder metals as there is less free movement in the layers of cations. they also have more areas of "disruption" and are more brittle
Organic Chemistry
The study of the structure, properties and reactions of organic compounds, which often contain carbon covalently bonded to itself and other elements, including hydrogen.
bio chemistry
the study of the chemical processes that occur within living things
medicinal chemistry
Many pharmaceuticals are hydrocarbons designed to mimic organic compounds found in the body. medicinal chemistry includes the design and synthesis of these compounds
crude oil
is a mixture of many organic compounds that are used as fuels, lubricating oils, within plastics and even as cosmetics
Alkanes
composed only of carbon and hydrogen covalently bonded
alkanes are a group/series of hydrocarbons that ONLY CONTIAN SINGLE BONDS
all the carbons in alkanes are saturated - meaning that all the carbon-carbon bonds are single covalent bonds
formula of alkanes
we can represent the formula of hydrocarbons using:
Lewis structures - show electrons in the molecule
structural formula - show all bonds in the molecule
condensed structural formula - show the atoms that are bonded together, but do not show bonds
Structural isomers
have the same molecular formula but different structural formulas
in alkanes - this is only possible for compounds with 4 or more carbon atoms
functional groups/side groups
a term used to describe a group of atoms in an organic molecule responsible for the characteristic
these functional groups replace a hydrogen
alkyl groups are functional groups that only have carbon and hydrogen present
naming functional groups
intermolecular forces
dipole
as two atoms form covalent bonds, electrons will spend more time closer to the more highly electronegative element
essentially these molecules have oppositely charged poles
we call these molecules with imbalanced electron distribution polar. molecules with a balanced electron distribution are non-polar
diatomic molecules
non-polar - the two atoms in the molecule have identical electronegativities
e.g: chlorine gas
polar - the two atoms in the molecule have different electronegativities
e.g: hydrochloric acid
Electronegativity is the tendency of an atom in a covalent bond to attract electrons. Molecules with an equal distribution of valence electrons are said to be non-polar because there is no charge on either end of the molecule. Molecules with an imbalanced electron distribution are said to be polar.
polyatomic molecules
the polarity of polyatomic molecules depends on the polarity of the covalent bonds, but also the shape of the molecule.
as a general rule
symmetrical molecules are non-polar
Asymmetrical molecules are polar
polyatomic ions
we treat polyatomic ions the same as polyatomic molecules, but you have to remember when drawing Lewis Structures to add or subtract sufficient valence electrons
a small electric charge assigned to atoms in a molecule
forces between molecules
factors that determine the strength or intermolecular forces:
molecule size
molecule shape
polarity
dipole - dipole forces
only occur in polar molecules
results from the attraction between positive and negative ends of polar molecules
strength of dipole - dipole forces
relatively weak because the charges on the molecule are small
the more polar a molecule is, the stronger the dipole-dipole forces.
Dipole-dipole forces occur in polar molecules, and are a result of the attraction between the positive and negatively charged ends of molecule
properties of substances
the stronger the dipole-dipole forces, the higher the melting and boiling points
this is because more energy (higher temperatures) are required to disrupt the intermolecular
hydrogen bonding
a special type of dipole-dipole force that occurs in molecules where a hydrogen atom is covalently bonded to oxygen, nitrogen or fluorine. The nitrogen, oxygen or flourine atom must have a lone pair of electrons.
hydrogen bonds are approximately 10 times stronger than a dipole-dipole bond. but 1/10 the strength of an ionic or covalent bond
oxygen, nitrogen and fluorine have a small atomic radius and are highly electronegative
they strongly attract electrons in a covalent bond , creating a partial positive charge on the hydrogen atom.
chlorine atoms are also highly electronegative, but do not form hydrogen bonds because of their larger atomic radius
the hydrogen atom only has one electron and this is strongly attracted to the highly electronegative N, O or F
the leaves the hydrogen atom "exposed" due to its lack of electrons and it is attracted to a lone pair of electrons on the N, O or F
dispersion forces
exist between non-polar covalent molecular compounds
caused by temporary dipoles in the molecules that are the molecules that are the result of random movement of electrons surround the molecule
dispersion forces are always present between molecules, molecules no matter whether they ae polar or non polar because electrons are always moving in atoms
strength of dispersion forces
increase as the size of molecule increases because larger molecules have larger numbers of electrons
because larger molecules have stronger dispersion forces, they also have higher melting and boiling points
molecule shape also influences dispersion forces: long chain molecules have stronger forces than compact molecules
solutions
solubility refers to the maximum amount of a solute that can be dissolved in a solvent to make a solution
unsaturated solutions
a dilute solution has a relatively small amount of solute is dissolved in the solvent
a concentrated solution has a relatively large amount of solute dissolved in the solvent
saturated solutions
a saturated solution cannot have any more solute dissolved at a particular temperature
a supersaturated solution is an unstable solution that contains more dissolved solute than a saturated solution. if this type of solution is distributed, some of the solute will separate from the solvent as a solid
precipitation
two different solutions are mixed, ions are arranged to form new compounds.
if a new compound that is formed is insoluble, then this reaction is called a precipitation reaction. the solid formed is called a precipitate
concentration
the relative amount of solute and solvent in a solution
concentrated
the ratio of solute to solvent is high
dilute
the ratio of solute to solvent is low
dilution
dilution is the process of adding more solvent to a solution
when diluting aa solution by adding more solvent, it does not change the amount of solute present
this means we can use the following equation to calculate a dilution:
(C1 V1) - solution original solution = (C2 V2) - diluted solution
units of concentration - grams per litre
the mass, in grams, of solute dissolved in 1L of a solution
we can express this as g/L or g L -1
concentration (g/L) = mass of solute (in g) divided by volume of solution (in L)
units of concentration - parts per million
the mass in grams of solute dissolved in 10000000g of solution/ the mass in mg dissolved in 1Kg of solution ( there are 1 million mg in 1kg)
used when very small quantities of solute are dissolved to form a solution
concentration (ppm) = mass of solute (in mg) divided by mass of solution (in Kg)
mg --> g divide 1000
g --> Kg divide 1000
molar concentration
molar concentration is the moles of a substance in 1 litre of a solution
it can be expressed as: mol/L mol/L-1 M
we can say: moles per litre, molar, it has a molarity of
to calculate molar concentration: M = n/V
moles/volume
calculate the molar concentration of a solution that contains 16.8mg of silver nitrate dissolved in 150mL of solution
step1: convert volume to litres
step2: convert mass to grams
step3: convert grams to moles
step4: calculate molar concentration
identifying ions in solutions
when two substances are mixed, the ions in solution can be determined using evidence from chemical reactions, including precipitation reactions.
chemistry data book:
Pg4
Pg5
collision theory
explains why some collisions result in reactions but others do not.
according to collision theory, for a reaction to occur, the reactant particles must:
collide with eachother
collide with sufficient energy to break bonds within reactants
collide with the correct orientation to break bonds within the reactants and so allow the formation of new products
if the collision orientation is incorrect, the particles simply bounce off each other and no reaction
concentration ( Aqueous solutions) and pressure (Gases)
both of these factors reduce the space between reactant particles and increase the frequency of collisions between reactant particles
surface area
when a particle is smaller, it is has greater exposed surface area.
this increases the frequency of collisions between reactant particles
energy of collisions
sufficient energy
the minimum energy that a reactants need for a successful collision to occur is called the activation
VSEPR theory
valence shell electron pair repulsion theory
uses the knowledge of the valence shell electron in the atom of a molecule to predict the shape of the molecule
negatively paired electron pairs on the valence shill of an atom repel each other and arrange themselves as far away from each other as possible
long pairs of electrons
not all electron pairs in molecules exist as covalent bonds. some electrons form a non-bonding pair of electrons known as a lone pair of electrons
in vespr theory, lone pairs electrons still take up space around the atom so are treated in the same way as electron pairs
how do we determine the shape of a molecule
step 1.
drawing the electron dot diagrams
A) what is the electron configuration of the atoms in the molecule
B) how many electrons does each atom need for a stable valence shell
C) draw the diagram of the molecule, ensuring each atom
ionic bonding
rules for writing formulae for iconic substances
the positive ion (usually a metal ion) is written first)
the negative ion (non-metal ion) is written second
the number of each ion is adjusted so that total positive charge equals the total negative charge. subscripts are used to indicate the number of each ion present.
if the compound contains a polyatomic ion, you must not change the formula of the ion. if more than one of that polyatomic ion is needed to balance the charge, brackets must be used to indicate that the number affects all parts of the polyatomic ion.
rules for naming iconic compounds
the meatal, or positive ion is named first and keeps its normal name.
the non-metal, or negative ion is named second and has the end of its name written as "ide","ate" or "ite"
if the metal ion has several valences possible, indicate its valency using roman numerals.
properties of ionic substances
high melting points
hardness and brittleness
electrical conductivity in the aqueous or liquid state.
the ionic bonding model
ionic substances exist as a 3D lattice held strongly together by the electrostatic force of attraction between cations and anions
pH
Measuring acidity
the more acidic a solution, the more hydrogen ions in the solution
because the range of concentrations of hydrogen ions varies so greatly, the pH scale was developed
the pH of a solution is defined as: pH = --log10[H+]
we can also rearrange this as [H+] = 10 -pH
standard temperature and pressure (STP)
Avogadro's law
at the same temperature and pressure, equal volumes of all gases contain equal numbers of particles
STP - A temperature of 0C (273.15k) a pressure of 100 kPa
the SI unit for temperature is kelvin (K)
molar volume
the volume of 1 mole of a gas at a given temperature and pressure.
at STP, most gases behave very like an ideal gas, and therefore have a molar volume very like an ideal gas
at STP, the molar volume (Vm) of 1 mole of a gas is 22.71 L.
potable water
another term for clean drinking water
sources of water
steps
evaporation
condensation
precipitation
major sources
desalination plants (43%)
ground water (39%)
dams (15%)
ground water replenishment (3%)
disalination
seawater contains about 3.5% dissolved salts so isn't suitable for drinking
desalination involves removal of dissolved alts and can be achieved by two process
distillation
reverse
distillation
salt water is heated until it boils, water vapour passes out of the flask and into the condenser. salt is left behind in the flask
the fuels required to heat the water are expensive so we don't use distillation in Australia. it is however used routinely in Dubai.
osmosis
osmosis is the natural tendency of water to move from a region of low salt concentration to high salt concentration
if salt water and fresh water are separated by a semipermeable membrane that allows water molecules but not the dissolved ions to pass through it, the water molecules will pass through the membrane to balance the concentration of salt in the two sections
reverse osmosis
this natural tendency can be reversed by applying pressure to the salt water side of the membrane. this process is called reverse osmosis
we use this routinely in Australia, including in two plants in WA
treating drinking water
in most Australian cities, water is treated before being passed on to consumers. this is usually to remove suspended solids, bacteria, colour and odour from the water
the four steps in most cities are
1) flocculation 2) settling of the floc 3) filtration 4) chlorination
Lewis structures
visualising Electrons in bonds
when forming an ionic compound, we know that the cation loses electrons which are then gained by the anion
we can visualise this using an electron transfer diagram
lewis dot diagrams
we can simply visualising electrons by only drawing valence electrosn
stoichiometry
steps
write a balanced equation
indicate known and unknown quantities
determine mole ratio (unknown/known)
convert known to moles
determine moles of unknown (using mole ratio)
convert unknown to mass
limiting reactants
steps for calculating limiting reactants
write a balanced chemical equation
calculate the number of moles for each reactant
use the coefficients of the reactant to determine the limiting reactant
use the amount of limiting reactant to work out the amount of product formed or the amount of reactant in excess
acid/bases and metal hydroxides/carbonates
acid + metal hydroxide --> salt + water
a salt is an ionic compound
acid and metal hydroxide reaction are neutralisation reactions
the low pH acid and high pH base react to form neutral solution
the salt is formed from the cation of the base and the anion of the acid
steps
what is the general reaction and what products will be formed?
what are the formulas and states of the reactants and products
what is the full equation for this reaction?
identify the spectator ions
rewrite the equation without spectator ions
acid + carbonate --> salt + water + carbon dioxide
diluting acids and bases
acids and bases are frequently purchased in concentrated solution as it is cheaper to ship. we the dilute them into a more diluted "usable" form.
we know that the concentration of a solution in moL-1 is calculated using c=n/V(in litres)
and that we can dilute a solution using C1V1=C2V2
we can use these same equations for calculations with acids and bases
ammonium salts
ammonium salts are similar to metal salts except the metal carbon (eg Na+) is replaced by the ammonium ion (NH4+)
bases + ammonium salts
Ammonium salt + base --> salt + Ammonia + water
reactive metals
reactive metals include:
group 1 and group 2 metals
main group metals
some transtion metals
copper, silver and gold aren't reactive
acid and reactive metals
when dilute acids are added to main group metals and some transition metals, bubbles of hydrogen gas are released and salt is formed
acid + reactive metal --> salt + hydrogen gas
relative isotopic mass
the mass of an individual isotope of an element compared to the mass of an atom f carbon-12
relative atomic mass
the weighted average of the relative masses of the isotopes of the element relative to carbon-12
human bio
The heart and Circulation
heart diagram
Link Title
the chambers
the heart consists of four muscular chambers
the two on the LHS are separated from the two on the right by the septum
the upper chambers - the atria - receive blood
the lower chambers - the ventricles - are the pumping chambers
the blood vessels
vena cave - carries deoxygenated blood from the body to the right atrium
pulmonary artery - carries deoxygenated blood from the right ventricle to the lungs
pulmonary vein - carries oxygenated blood from the lungs to the left atrium
aorta - carries oxygenated blood from the left ventricle to the body
the valves
the direction of the blood flow is controlled by four valves
the atrioventricular valves are held in position by strong tendons, the chordae tendinae (tendineae)
the heart sounds - "lubb dubb" - result from the valves snapping shut.
heart beat
the heart contains specialised conductive tissue which regulates the heart beat
the sinoatrial node (SA node or pacemaker) is a cluster of specialised cardiac cells in the wall of the right atrium which initiates the heartbeat
the atrioventricular node (AV node) is the secondary pacemaker which regulates the beating of the ventricles
the lymphatic system
the lymphatic system is a one-way drainage system that carries lymph from body tissues back to the general circulation.
lymph is a clear yellow liquid that carries white blood cells, especially lymphocytes
the lymphatic system - structure
lymph vessels pass through a series of lymph nodes
lymph vessels are thin walled vein like tubes that carry lymph
lymph nodes are small bean shaped structures that contain high concentrations of macrophages and lymphocytes.
the lymphatic system - function
the function of the lymphatic system are:
to return excess tissue fluid to the circulation
to filter out cellular material, including pathogens and cancer cells
to activate the immune system
lymphatic tissues
structures in the body that contain lymphatic tissue, but are not part of the lymphatic system, include:
the spleen
Thymus gland
Tonsils
Peyer's patches in the gut
The appendix
urinary system
functions of the kidneys
to rid the body of wastes, especially nitrogenous wastes such as urea.
to regulate the balance of fluid, salt and pH
they achieve these outcomes by filtering the blood as it passes through the kidneys.
waste substances are removed by the processes of filtration and tubular secretion
useful substances are returned to the body by the process of selective reabsorption
structure
the major structural components of the urinary system are:
kidneys x2
urinary bladder x1
ureters x2
urethra x1
components of kidney
medulla
cortex
renal vein
renal artery
ureter
capsule
renal column
pyramid
renal pelvis
major calyx
minor calyx
papillae
kidneys
Nephron
the functional unit of the kidneys is the nephron
a nephron consists of a Bowman's capsule, a renal tubule and their associated blood supply
each kidney contains approximately one million nephrons
the renal corpuscle
filtration takes place in the renal corpuscle
the renal corpuscle consists of the Bowman's capsule and a mass of blood capillaries - the glomerulus
protein synthesis
protein synthesis (also known as gene expression) is the conversion of the genetic code carried by DNA into an end product i.e usually a protein
protein synthesis involves the processes of transcription and translation
proteins
a protein is a member of a family of organic compounds consisting of long chains of amino acids.
The blood vessels and circulation
blood vessels - structure
the outer layer of the blood vessel is the TUNICA EXERNA under that is the TUNICA MEDIA and under that is the TUNICA INTERNA (ENDOTHELIUM)
tunica interna is present in - arteries, capillaries and veins
tunica media is present in - arteries and its well developed but aren't in capillaries and are present in veins but are thin
tunica externa are present in - arteries but are relatively thin but aren't present in capillaries and are present in veins and are well developed
double circulation
systemic circulation and pulmonary circulation
pulmonary circulation
the pulmonary circulation takes deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atrium
the right ventricle is the pump for the pulmonary circulation
the systemic circulation
the systemic circulation takes oxygenated blood from the left ventricle to all the tissues of the body and returns deoxygenated blood to the right atrium
the left ventricle is the pump for the systemic circulation
cells
mitosis
mitosis is a process of nuclear division that forms two daughter cells with identical sets of chromosomes (the diploid chromosome number
mitosis is a form of nuclear division
all somatic (non-reproductive cells) are formed by mitosis
each cell produces two daughter cells
daughter cells contain the same number of chromosomes as the original cell ( the diploid or 2n chromosomes number). in this way every cell obtains a complete set of genetic information
the stages of mitosis
prophase
first stage
during this stage:
-chromosomes condense
-nuclear membrane breaks down
-centrioles migrate to the poles of the cell
-spindle forms
metaphase
during metaphase the condensed chromosomes move to the middle of the cell (the equator) and become attached to the spindle fibres.
anaphase
during anaphase the sister separate and are dragged to opposite poles of the cell
telophase
telophase is the final stage in mitosis and is the opposite of prophase
during telophase:
-the two sets of chromosomes uncoil
the nuclear envelopes reform
the spindle fibres disappear
pe studies
method training
resistance training
benefits
helps prevent osteoporosis
improves psychological wellbeing
increases strength - allows an increase in force production which can be adapted for improvements in both power and speed
isotonic
muscle changes length working against a constant load e.g. bicep curl, bench press etc
concentric contraction
muscles shortens during contraction e.gs raising phase of bicep curl
eccentric contraction
muscle lengthens during contraction
aims to build muscle strength, muscle power or local muscular endurance by exercising muscles or muscle groups against a resistance.
isokinetic
an isokinetic force is one which results in a change in the length of a muscle, however is performed against varying load
isometric
if the muscle length does not change, then an isometric contraction or force is being applied
interval training
a series of repeated bouts of exercise interrupted by pre-determined rest periods or lighter exercise
continuous training
used to improve aerobic fitness and local muscular endurance
circuit training
combination of high intensity aerobic and resistance training completed in a given time or by a pre-determined work: rest ratio
comprise of 10 - 20 stations, with participants spending 45-60 seconds at each station, with a 30 second rest in between each
fartlek
modified version of continuous training involving continuous activity interrupted by random changes in pace
used to develop aerobic endurance and speed
flexibility
static stretching
muscle is held at its maximum range for a period of up to 30 seconds
dynamic stretching
muscle is moved through a large range of motion, designed to emulate the expected movements you engage in during physical activity
plyometrics
training method designed to produce fast, powerful movements, and to improve the functions of the nervous system
training principles
specificity
involves the training of specific energy systems, fitness components, muscle groups positions and roles with a given sport
intensity
amount of effort applied in a training activity or session
measured using the following
heart-rate (%HR max)
oxygen uptake (%V02 max)
lactate concentration
duration
length of time required to improve iin a training program. this can include time spent during:
each session (minutes)
20 minutes duration is required to make aerobic gains in a continuous activity
frequency
how often one trains per week
Aerobic training for beginners requires 3 sessions per week to improve
endurance athletes may train 5-6x per week due to the submaximal nature of training
progressive overload
involves a gradual increase in workload done by the athlete. it is applied once adaptation has occurred to certain stimulus
increase frequency
increase duration
increase intensity
increase distance
reversibility
the loss of physiological performance (detraining) occurs as a result of a person terminating or scaling back a regular training program
this usually tarts in the first 1-2 weeks and increases the longer the athlete remains out of training
Nutrition
A balanced diet contains a healthy amount of macronutrients - proteins CHO and fats as well as essential minerals, vitamins and water
The amount of energy we cinsume each day is dependent on number of factors
These include: 1. The age of the individual
2.the sex of the individual
3.their level of physical activity
Periods of growth
Protein
Growth of muscle tissue
Repair of muscle tissue
3.production or red blood cells, hormones and antibodies
Contribution to ATP production when carbohydrate and fats stores are are depleted
Fats and lipids :
Represents body's most plentiful source of potential
Carbohydrates (CHO) : :
First converted to blood glucose leading to rise in insulin levels
Excess blood glucose converted in to glucogen
Glycemic index
Ranking of carbohydrates based on their immediate effect on blood glucose (blood sugar)
Low Gi
Break down slowly during
motor learning and coaching
motor learning is focused around two key elements which will be explored further
motor programs
organised set of individual motor skills (or subroutines) that result in the correct execution of a specified skill
success of motor programs is dependent on individual motor skills being executed with correct timing and being placed in the correct order or sequence
-->through learning, motor programs are stored in the performers memory and called upon when required to complete a given task
--> in completing the task, the performer combines a series of smaller tasks to perform the larger movement
motor skills
skill categories
cognitive skills - involving primarily the brain e.g. reading, analysing a problem
perceptual skills - involving how an individual interprets stimuli e.g. two players receive the same information from the environment but interpret it differently. correct interpretation of stimuli improves performance
motor skills - involving physical movement e.g. catching, throwing, running
movement skills are often classified under the following continuums:
movement precision
type of movement
predictability of the environment
characteristics of motor skills include;
skills require a relatively complex sequence of movements
they are learned and require practice to improve
they have pre-determined goals and objectives
motor learning is a discipline concerned with the learning of skilled movements through biophysical knowledge about neutral, muscular and sensory systems, practice and feedback
energy systems
ATP (ADENOSINE TRIPHOSPHATE) / CP (creatine phosphate) system
ATP is stored in our muscle fibres
ATP is the only form of energy our body uses and it is is in very short supply
ATP lasts 2 secs of energy
CP lasts about 7-8 sec
combined they last 10 seconds and are used for power sports
ATP - CP supplies recover quickly (3-4min)
lactic acid system
ATP is re synthesised by the breakdown of carbohydrate
serves as a back up system for ATP - CP system and aerobic system
requires approximately 60-90 min between events for optimal recovery
lasts for 45-60 secs
Aerobic system
requires oxygen
all day, everyday energy system
CHO are the preferred energy source during high intensity exercise as it costs the body less energy to produce ATP than fat.
stored glycogen in the muscles is broken down to glucose. when the glycogen in the muscles is depleted, glycogen in the liver is used
quantitative vs qualitative analysis
qualitative analysis tells you what is there
quantitative analysis tells you how much is there
HPLC and GC can be used for quantitative analysis. to do this, we construct a standard curve
PE Studies
