MCS Flashcards
What is conformation?
Unique 3D shape of a protein
- Conformation depends on amino acid sequence
FUNCTIONS: (7)
1) Enzymatic catalyst
2) Systematic movement ( muscles)
3) Transport and storage of small molecules and ions.
4) Mechanical System ( skin and bones)
5) Immune system ( Anti bodies)
6) Communication:
- Hormones: Some hormones are proteins
-cellular receptors and neurotransmitters are proteins
7) Growth and Differentiation( Controlling gene expression):
- Repressor proteins supress DNA sequences
- Transcription and Translation.
All amino acids are optically active, except which one?
Glycine
What is an Imino acid?
An amino acid with a secondary amino group..
What is an example of an imino acid?
Proline.
What configuration is required for amino acids to be optically active?
L configuration.
What is D- configuration?
Bacteria and Invertebrates.
What does amphoeteric mean?
BOTH acidic and basic properties.
- amphoteric properties, depend on how easily side chains dissociate.
What is a “left handed isomer” classified as?
L isomer
What is a “right handed isomer” classified as?
D isomer.
isoelectric point:
Point at which overall charge of protein is ZERO
Are proteins branched or unbranched
Proteins are unbranched polymers.
What is a “residue” ?
Amino acid in a poly peptide chain.
Poly peptides are formed by what type of reaction?
Condensation.
When is an amino acid protanated/deprotanated?
If ph is higher than pka, then it is deprotonated.
If ph is lower than pka, then it is protonated.
Globular:
tight folding poly peptide chains.
SOLUBLE
Fibrous:
Straight poly peptide chains forming fibres or sheets
INSOLUBLE.
STRUCTURE? Covalent, back bone
and amino acid sequence:
Primary Structure
STRUCTURE? Bonds between other neighbouring residues
Secondary strucure
Bonds involved in the Secondary structure
Hydrogen bonding
Ultimately, forming alpha helix or beta pleated sheets
Hydrogen bonding (HELICAL):
If the h-bonds form between peptide bonds in the SAME CHAIN.
Hydrogen bonding( EXTENDED structures):
If h-bonds form between peptide bonds in different chains.
Alpha helix brief description:
Rod like structures with peptide bonds coiled tightly inside.
- side chains face outwards
- coils turn in a clockwise direction.
- There are 3.6 residues, per turn of helix.
Beta- pleated sheets
c-c bonds are tetrahedral
chains lay side by side
- chains may run in the “same directions” ( Parallel beta sheets)
What does “pleated” mean?
C-C bonds are tetrahedral, and can’t be in straight lines.
What’s the anti-parallel Beta strucutre:
E.g. when chains run in opposite directions to each other.
For example, in a globular protein.
How would an anti parallel beta structure be likely to form?
When an EXTENDED structure folds back on itself.
STRUCTURE? Spatial arrangement of residues:
Tertiary Strucuture.
Hydrophillic chains are
OUTSIDE
Hydrophobic chains are
INSIDE
What is the electrical state of a monoamino?
Electrically neutral
what does folding indicate?
State of greatest stability.
Conformation: At points of instability:
At points of instability, FLEXIBILTY in the chain allows water to gain maximum energy.
- Which helps form the strucuture.
STRUCTURE? Arrangement of polypeptide chains in a multi-chain protein:
Quaternary strucutre.
What is Denaturation?
Disruption of weak types of interactions:
such as:
- h-bonds
-vdw
-ionic links
- Hydrophobic/hydrophilic interactions
Advantage of “disruption” :
Helps to maintain the 3D shape of a protein
Disadvantage of Disruption
Causes a decrease in biological activity.
What does “LABILE” mean?
Means a protein is EASILY DISRUPTED
What external factors could cause disruption?
- extreme temperature/ pH
- High salt concentrations
- Organic solvents.
Where is collagen found in the body?
Skin, cartilage, tendons, blood vessels, bones and teeth
How many strands in collagen and how long is each strand roughly?
Fibrous protein
3 strands
each strand is roughly 1000 residues long.
Repeating motif of collagen?
GLY-PRO-PRO
I
OH
What is2 things are special about collagen?
1) LOCKING EFFECT
2) SUPER HELIX FORMATION
Locking effect:
- Due to stability of PRO-PRO
I
OH - And due to H-bonding between residues.
Super helix formation:
Due to amino acid occupying every 3rd residue.
Is a globular soluble/insoluble
SOLUBLE
Is a fibrous protein soluble/insoluble
INSOLUBLE
Protein folding disease:
Ultiamately causes anemia.
A single mutation changes a glutamic acid in B-globulin chain, into a valine.
- Causing protein to change conformation
- which causes hydrophobic part to become EXPOSED
which causes polymerisation
Which causes genetic mutation in homozygous individuals.
What does GENETIC MUTATION from protein folding disease cause?
Reduces ELASTICITY in red blood cells
Causing Sickle cell anemia.
5 ways to treat sickle cell anaemia?
1) Sickle cell pain: Hydroxycarbamide
2) Sickle cell crisis: paracetamol/ibuprofen
- A warm towel on affected body part
3) Prevent infections: Daily dose of antibiotics. (e.g. penicillin)
4)If SEVERE: blood transfusions, folic acid, hydroxycarbamide
5) Sickle cell care: Stem cell/bone marrow transplant
Advantage of Hydroxycarbamide as a treatment?
Increases levels of haemoglobin.
Disadvantage of hydroxycarbamide as a treatment of sickle cell anaemia?
Could decrease levels of white blood cells and platelets
What is a disadvantage of stem cell/ bone marrow transplant as a treatment:
Transplanted cells could attack host cells.
Strongest to weakest bonds:
From strongest->weakest
Covalent
Ionic
Hydrophobic/hydrophilic interactions
H-bonds
Van der Waals.
Calculating buffer range of an amino acid:
Calculating buffering range of an amino acid:
pH= pka +- 1
pH calculations
pH = pka + log (HCO3-)/ (H2CO3)
Ka= (H+)(A-)/(HA)
Pka= -log ka
Ka= 10^-pka
Pneumonic to remember amino acids:
Phenyloanine - aromatic non-polar
R
Valine
Trytophan - aromatic non polar
Isoleucine
Methionine
Thernonine- aliphatic hydroxyl
Histidine- polar
Arginine- polar
Leucine- polar
Lysine- polar
What is an enzyme?
proteins that act as biological catalysts
What is a cofactor
organic molecules.
Where are enzymes found?
mitochondria
lysosome
Endoplasmic reticulum
What are coenzymes?
Small cofactors
prosthtic group is a …..
Tightly bound coenzyme
Cosubstrate is a…
loosely bound coenzyme.
What is glycolysis
Pyruvate -> glucose
What is gluconeogenesis
Opposite of glycolysis
Glucose -> pyruvate
What enzyme breaks down long fatty acid into “acetate” ?
Beta-ox
whereas acetate-> long fatty acid chain
is catalysed by the enzyme “FAS”
4 ways how enzymes catalyse reactions:
1) provide reactive surfaces and a suitable environment
2) Brings reactions together and allows transition state to be reached.
3) Weakening bonds in reactants
4) Reduces energy required to reach “transition state”
What is transition state?
State where the substrate is no longer a substrate, but not a product either.
Enzymes vs Inorganic catalysts: (4)
1) Enzymes are chemically similar, whereas inorganic catalysts are chemically diverse
2) Enzymes are LABILE, whereas I.O are stable to heat
3) Enzymes are specific whereas I.O are non-specific
4) Enzymes are inhibited in a specific way, whereas I.O tends to not be inhibited.
Things in common between Enzymes and Inorganic catalysts:
BOTH unchanged at the end of a reaction
BOTH don’t affect final equilibrium.
( But allow equilibrium to be reached faster)
Enzyme specificity (In DECREASING order);
1) ABSOLUTE
2) STEREOCHEMICAL: PREFERS “D” OVER “L”
3) Group/function
4) LOW: gluthathione- s transferse: can catalyse a large number of substrates.
Denaturation of an enzyme=
Loss of biological activity
DEFINTION
What is a “unit of enzyme activity” ?
The amount of enzyme causing transformation of 1 micro mol of substrate per minute at 25 degrees celcius.
DEFINITION
What is “specific activity” ?
Number of units of enzyme activity per mg of enzyme protein.
DEFINITION
What is KATAL (KAT)
Amount of enzyme activity that transforms one mol of substate per second.
For “reaction velocity” , [ S] graphs:
Increasing [E] will increase reaction velocity, as long as there is enough substrate molecules to bind to it.
For reaction velocity, [E] graphs:
Increasing substrate concentration will increase rate at which products formed up to a max value (Vmax).
Vmax graph:
At Vmax active sites are full, so graph plateaus.
Turnover number of an enzyme equation:
Vmax = K2 [ E ] T
What is “Kcat”
Kinetic constant
DEFINITION
Turnover number of enzyme
Number of substrate molecules converted to products, when enzyme’s active site is occupied with substrate.
Catalytic efficiency equation:
See notes
When [ S ] is less than Km: (4)
1) [E] is roughly same as [ET]
- [ET] is just the total enzyme concentration
2) Velocity of catalysis depends on Kcat/Km, [S] and [ET] values.
3) Kcat/Km is rate constant for S and E and can be used as a measure of catalytic efficiency.
4) You can use Kcat/Km values to determine an enzymes preference for different substrates.
What does it mean if a reaction is at Vmax?
Enzymes cant work any faster
Active sites are full
Units: Conc/time
DEFINITION
Km:
[S] at which reaction velocity is at half maximal.
units: Molar (M)
Siginificance of Km
Using mathematical proof
We find that Km = [S]
How can Km be applied to “affinity” ?
Km is a measure of affinity of an enzyme for its substrate.
What does a lower km mean for “affinity” ?
Lower km means
GREATER AFFINITY
What does inverting michaelis-Menten equation do graphically?
Turns hyperbolic curve into a straight line equation.
- kinetic parameters can be accurately estimated.
What type of graph is lineweaver bunk plot?
Straight line graph
What are the 2 types of enzyme inhibition:
Competitive and non-competitive inhibition
Competitive inhibition:
- Bind to the active site through intermolecular bonds
- Reversible reactions
- Increase in substrate concentration lowers the chance of competitive inhibitor binding.
- DON’T alter Vmax.
Non competitive inhibitor:
- Bind to allosteric site: can inhibit reaction without affecting strength of substrate bonding.
- Km unchanged
- Non competitive inhibitors decrease Vmax.
-Reversible/irreversible
- Non competitive inhibition disrupts active sites.
Allosteric enzymes:
Modulation
I
Inhibition
I
Activation
I
Co-operating
DEFINITION:
Homotropic Allostery:
Binding of identical molecules in a co-operative manner.
DEFINTION:
Heterotrophic Allostery:
Co-operative binding of some other substances as well as the substrate.
What does Allosteric activator do?
Increases activity
What does Allosteric inhibitor do?
Decreases activity.
What is Kcat and K2.
They are the same thing.
The kinetic constant K2 is Kcat
What are the rate laws for competitive and non competitive inhibitors?
Look at rate laws on notes.
- competitive inhibitor only binds to E
- non competitive inhibitor only binds to ES
What is Ki?
How potent an inhibitor is.
- concentration required to produce half maximum inhibition
Catabolism:
Breaking down of large complex molecules, into smaller simpler ones.
tricarboxylic acid pathway=
Kreb cycle.
cori cycle:
Cycle involving glucose lactate and alanine.
What is the normal level of plasma NH3
0.5mg/L
Urea cycle:
- only in the liver
- MAIN PURPOSE: DETOXIFICATION
Irreversible - maintain ratio of urea: ammonia ( 500:1)
What does fumarate break down into:
Fumarate
malate
oxaloacetate ( NH2 transferred to oxaloacetate makes Asparate)
Asparate (Asparate combines with Acetyl CoA to create citrate)
Citrate
Pyruvate -> glucose
What are the basic metabolites?
1)Acetate
2) Acetone
3) urea
4) pyruvate
Glycolysis process:
glucose
fructose1,6-bisphosphate
2x3 carbon compounds ( oxidised to pyruvate) and ATP is produced
pyruvate
Enzymes involved in Glycolysis: (the 3 kinases)
1) Hexokinase - catalyses the phosphorylation of glucose
2) Phosphofructokinase- catalysed fructose 6 phosphate to fructose 1,6 bisphosphate using ATP
3) Pyruvate kinase
What is the function of hexokinase:
- Catalyses transfer of phosphate from ADP to Oh group on the 6th carbon to form glucose 6 phosphate.
What is the function of phophofructokinase?
Catalyses phosphorylation of fructose 6 phosphate to produce fructose 1,6 phosphate.
What is the function Pyruvate Kinase?
Catalyses transfer of phosphate group from phosphoenolpyruvate (PEP) to ADP to produce pyruvate.
Regulation of glycolysis pathway:
1) Hexokinase inhibited by glucose 6-phophate.
2) Phosphofructokinase: Inhibited by ATP, lowers affinity for fructose 6 phosphate
3) Pyruvate kinase: L- type found in the liver
M- type found in the muscle and brain
What does fructose 1,6 bisphosphate do?
Activates both pyruvate kinase isozymes (L and M type)
What does ATP do (regarding pyruvate kinase)?
Inhibiting both forms (L- type and M type)
- to slow down glycolysis
How is alanine involved with pyruvate kinase?
Alanine allosterically inhibits it.
What is Beriberi?
A neurologic and cardiovascular caused by deficiency of thiamine.
Beriberi:
prosthetic group: Thiamine pyrophosphate
for the enzyme pyruvate dehydrogenase, alpha ketoglutarate dehydrogenase
- transketolase.
What does low transketolase activity indicate:
Beriberi of red blood cells.
What are the end products of KREBS:
CO2 and NADH
High energy electrons from NADH passed onto ETC.
KREBS carbon input and output:
2 carbons IN from acetyl CoA
2 carbons OUT as they leave as CO2
Regulation of Krebs cycle
Main regulators are Allosteric enzymes.
What are the allosteric enzymes that regulate the krebs cycle?
1) Isocitrate dehydrogenase
2) alpha- ketoglutarate dehydrogenasee
Isocitrate dehydrogenase (krebs)
Simulated by ADP, enhances the enzymes affinity for substrates
What inhibits isocitrate dehydrogenase?
1) NADH, by displacing NAD+
2) ATP
Alpha-ketoglutarate dehydrogenase
What is it inhibited by?
Succinyl Co A ( it’s catalytic products)
NADH ( it’s catalytic products)
ATP
What are the different proton pumps in ETC (3)
1) NADH-Q
2) Q-cytochrome C oxidase
3) Cytochrome C oxidase
Q:ubiquinone
Pump 1:
Reduced form “Q”
carries electrons from pump 1 to pump 2.
Pump 2:
Ubiquinone carries electrons from FADH2 to pump 2
What does succinate Q reductase do?
transfers electrons from FADH2 to ubiquinone.
Pump 3:
Cytochrome C allows electrons to pump 2 to pump 3.
What does pump 3 do?
Catalyses reduction of oxygen.
Proton Pumping: ETC
1) As electrons pass through the ETC, they fall into lower energy states
2) Energy is used to protons from matrix to the intermembrane space
3) A gradient of H+ ions is generated.
ADP + Pi -> ATP
What is the electron acceptor?
Oxygen.
ATP synthase consists of…
2 sub units (f0 and f1)
f0:
forms a channel which protons can cross the lipid bilayer
f1:
Gathers free energy derived from proton movement down chemical gradient.
How is ETC regulated?
Regulated by ADP levels
- unless ADP- > ATP, electrons don’t usually flow through the ETC
Way of remembering afferent and efferent.
Afferent
Efferent
Arrives
Exits
Afferent neurones:
Signal travels from peripheral tissue to CNS
Efferent neurones:
Signal travels from CNS to peripheral tissue
what does “amitotic” mean
Not able to divide
What is the input region of the neurone?
Dendrites
What is the conducting component of the neurone?
Soma
What is the output region of the neurone?
Axon.
What is the cell body and what is special about it?
The cell body is the biosynthetic CENTRE OF THE NEURONE
- cell body does not contain centrioles.
What’s a good attribute of dendrites?
They provide a large surface area.
DENDRITES:
- receive the signal inputs which gets converted into “charge of membrane voltage” (Vm).
CELL BODY:
The cell body= Large nucleus with a nucleolus.
- surrounded by granular cytoplasm
- mitochondria throughout
- microtubules throughout
which are important for intracellular transport and maintaining cell shape.
Function of the cell body:
Producing proteins and neurotransmitters.
- And transfers “changes in Vm” to axon hillock.
AXON HILLOCK:
First part of the OUTPUT pathway
- generates action potential if enough stimulation is received from the cell body.
- Expresses the ion channels that are needed for action potential.
AXON:
Each neurone has 1 axon arriving from the axon hillock.
- Different axons vary in diameter
^ which affects conduction - Axons allow “axoplasmic transport” to nerve terminals.
What are axon branches known as?
Axon collaterals.
What is the charge of a membrane at rest on the OUTSIDE and INSIDE?
OUTSIDE= positive charge
INSIDE= Negative charge
Depolarisation:
When positive and negative swap themselves, after an action potential has flown down an axon.
Repolarisation:
After a nerve has carried out is action, it can be recharged.
- Nerve can carry out its function again.
What does “amphipathic” mean?
Readily forms bilayers.
- hydrophillic substnaces cant readily diffuse in/out.
What does “amphipathic” mean?
Readily forms bilayers.
- hydrophilic substances cant readily diffuse in/out.
What is the Membrane Potential for MOST cell types?
-50mV
What is the Membrane Potential for “resting skeletal muscles” ?
-90mV
What is the membrane potential for neurones?
(-65 to -70 mV)
What is the Na+/K+ ATPase pump?
For active transport powered by ATP
Do most animal cells have higher intracellular concentration of “K+ or Na+ ions “
K+
- higher concentration of K+, causes an ionic gradient to be generated.
What fraction of a resting cell’s ATP is used to power the Na+/K= ATPase pump?
1/3
What are the 3 functions of the pump?
1) Control cell volume
2) Allows nerves and muscle cells to get electrically excitable.
3) Drives the active transport of sugars and amino acids.
- BONUS: helps to polarise membranes
For NA+/K+ ATPase pump, INSIDE is the cell losing +ve charge or gaining +ve charge?
LOSING +VE CHARGE.
this is because 3Na+ ions are outputted, and 2 K+ ions are inputted.
For NA+/K+ ATPase pump, OUTSIDE is the cell losing +ve charge or gaining +ve charge?
OUTSIDE OF THE CELL, GAINS +VE CHARGE
What is an ion channel?
Proteins that span across membrane and form selective pores.
- This increases the PERMEABILITY, allowing transfer of ions down their electrochemical gradient.
What are the 2 ways ion channels can be operated?
1) Ligand operated (ionotropic)
2) Voltage operated
Sodium ion channel:
- Has 4 repeating units
”+” helix contains many lysine and arginine residues.
- membrane depolarisation shifts the position of the helices, OPENING THE CHANNEL.
How is the sodium channel caused to be open?
Depolarisation causes positions of helix to shift
opening the channel.
What are the general steps of the normal nerve function? ( different types of polarisation etc)
1) Na+ channels open, depolarising the membrane, allowing an action potential to be fired
2) K+ channels open repolarising the membrane
- Na+/K+ ATPase pumps ensure ions are in the right place.
What do “volatage operated sodium channels” do?
They control nerve conduction.
What are “anaesthetics” and how do they work?
They interfere with the inhibition of nerve conduction,
by diffusing into axons and stopping Na+ channels.
What can A LOT of anesthetics cause?
Nerve blockage
as an action potential can not be fired.
Types of drugs that block channels:
- Anaesthetics
-Antiepileptics (phenytoin) - Antidysrhythmic (disopyramide)
- Tetrodotoxin
- Saxitoxin
- Conotoxins
Types of drugs that block inactivation:
- Batrachotoxin
- Scorpion toxins
- DDT
- Pyrethroids
Where does an action potential start?
At the axon hillock
- Action potentials tend to flow in ONE DIRECTION ( down the axon).
If prior to depolarisation the Vm was -65mV, what would it be after depolarisation.
+60mV
Action potential propagation:
Small diameter axons and Large diameter axons
Small diameter axon=
High resistance
and slow conduction speeds
Large diameter axons=
Low resistance
and faster conduction speeds.
What is myelin sheath made up of
And what is the function
- Made up of Schwann cells
- Rapid fire of action potentials
How does a few ion channels affect myelin sheath?
Ensures that myelin is a good electrical insulator.
Oligodendrocytes:
Myelinating cells of CNS
- They insulate multiple axons
Are dendrites myelinated or unmyelinated?
Dendrites will always be UNmyelinated.
What is saltatory conduction, and what is the benefit of it?
Salatatory conduction is when action potentials JUMP FROM NODE TO NODE (nodes of ranvier)
What is saltatory conduction, and what is the benefit of it?
Saltatory conduction is when action potentials JUMP FROM NODE TO NODE (nodes of ranvier)
Axon Classification:
A= myelinated axon
alpha, beta, mew, delta = Diameter of axon
C= UNmyelinated neurone
What are synapses and what do they do?
Synapses are gaps between neurones.
Synapses are involved in cell signalling and communication.
where do the signals jump from?
Signal jumps from synaptic cleft
to
receptors on new cell.
What are unipolar neurones:
Sensory neurones
Neuromuscular junction:
Somatic neurones release the neurotransmitters ACh which bind to nicotinic receptors.
if THRESHOLD is reached (neuromuscular junction)
Then EXCITATION OCCURS, and skeletal muscle fibres contract.
What receptors are stimulated via the release of ACh by parasympathetic postganglionic fibres?
muscarinic receptors.
What do most sympathetic postganglionic fibres release?
Noradrenaline,
which binds to adrenergic receptors.
- sympathetic postganglionic fibres innervate(give nervous system) sweat glands.
Difference between ligand receptors and metabotropic receptors?
Ligand receptors are fast acting, but last for short periods of time,
Metabotropic receptors are slower acting
What can G protein’s response affect?
May affect secondary activation.
- products formed from these responses are called secondary messengers.
At REST what do G protein’s alpha sub units bind to?
GDP ( Guanine di phosphate)
When STIMULATED what do G protein’s alpha sub units bind to?
GTP
AXOPLASMIC TRANSPORT:
Transport of vesicles around the axon.
What does Na+ ion cause?
DEPOLARISATION
(EPSP) excitatory postsynaptic potential. (more POSITIVE than -65mV)
What does K+ ion cause?
HYPERPOLARISATION
(IPSP) Inhibitory postsynaptic potential. (More NEGATIVE than -65mV)
What happens when a neurotransmitter is removed from synaptic cleft
( by break down or reuptake)?
Synapses are switched OFF.
What predicts the direction of ion movement?
Electrochemical potential. (µ)
Nernst Equation:
E = RT / zF ln( [ion]o / [ion]i)
“E” is equilibrium potential of an ion.
( Vm at which the ion will not flow)
What is the Goldman equation for?
- Allows us to calculate Vm
- Allows us to calculate Vr (resting potential)
-Allows us to work out relative permeabilities of different ions.
Donnan’s law (membrane charge distribution):
Describes how charged particles near a membrane fail to distribute evenly between the 2 sides.
What are the 3 things that depend on whether or not an action potential is FIRED?
1) Voltage dependent NA+ channels
2) Voltage dependent K+ channels
3) Depolarisation threshold for Na+ channels
What is the refractory period of a neurone?
Recovery time, during which a neurone will not respond to a stimulus.
What are the 2 types of refractory periods?
1) Absolute refractory period
2) Relative refractory period
Absolute refractory period:
When a neurone can’t carry another action potential. ion channels close.
Relative refractory period:
Occurs during a period where a 2nd action potential can be generated.
- “Initiation step” requires a stronger stimulus though.
What does the strength of a stimulus depend on?
Depends on the number of action potentials being carried.
What is the Cardiovascular system composed of?
Composed of:
The Heart, 2 networks of blood vessels
( systemic and pulmonary circulation)
Multicellualr advantages
1) Efficiency
2) Specialisation of cellular roles increase ability to survive and reproduce
Multicellular disadvantages:
1) Dependent on the function of other cells
2) Size of an organism
3) Delivery of nutrients
4) Removal of wastes
5) Communication co-ordination of function.
What does a circulatory system mean for large multicellular:
- Transport of nutrients
- Transport of O2
- Transport of CO2
- Transport of other waste products
what percentage of our body weight is blood?
Around 8%
What is plasma:
Straw coloured fluid containing proteins and dissolved salts.
What does plasma consist of:
water (90%)
proteins (8%)
non protein (urea etc)
nutrients ( carbohydrates, amino acids etc)
electrolytes (Na+, K+, Ca2+, Mg2=, Cl-, SO4 2-, HCO3-).
What helps to maintain oncotic pressure in the plasma?
Albumin ( protein)
Electrolytes
-Also help to maintain normal blood pH.
What are Leukocytes and what is their function?
they can leave the circulation and enter into tissues to kill/get rid of bacteria, viruses, toxins etc.
What are the different types of Leukocytes:
1) Granulocytes: granules in the cytoplasm can be easily stained.
- Neutrophils
- Eosinophils
-Basophils
^ all these are types of granulocyte.
Neutrophils:
Contain granules of hydrolytic enzymes( lysosomes) and “defensins” (poke holes in the opps membrane)
- Attracted to sits of inflammation, they can engulf invading cells.
Eosinophils:
- Don’t contain enzymes that specifically target bacteria
- They are focused on attacking parasitic worms (eg. tapeworm).
Basophils:
- Contain large amounts of histamine,
which dilates the arterioles when release,, increases postcapillary venule permeability and attracts other leukocytes to the area
What is a Agranulocyte?
Include lymphocytes and monocytes
What is the difference between granulocyte and agranulocyttes?
One has granuls in cytoplasm , one doesn’t.
What is the difference between granulocyte and agranulocytes?
One has granules in cytoplasm , one doesn’t.
Lymphocytes:
Exist in large numbers
- most are found in lymph nodes.
What do T lymphocytes and B lymphocytes combat?
- T lymphocytes attack virus infected cells and some tumours.
- B lymphocytes form plasma cells to produce antibodies.
Monocytes:
Attack viruses and bacteria
- they leave the blood and enter into tissues to form macrophages.
platelets:
Help to reduce or stop blood loss
they are tiny
and have no nucleus
made of fragments called megakaryocytes
platelets can release molecules that activate other platelets
What are platelets made up of ?
5-HT ( causes vasoconstriction to reduce blood flow to damaged area)
ADP
platelet-derived growth factor
ca 2+ ions
enzymes
What does 5-HT help do in platelets
5-HT
causes vasoconstriction, reducing blood flow to the damaged area.
how do platelets help join damaged blood vessels together
Platelets contain smooth muscle, which contract and bring the edges of the damaged vessels together.
Erythrocytes:
biconcave in shape (large SA:V ratio, increases rate of gas exchange).
no nucleus
contain Hb
Hb readily binds with O2
Gas exchange ( erythrocytes) :
The dark red deoxygenated erythrocytes pick up oxygen from the alveoli.
The oxygen then binds to Hb, causing the enthrocytes to turn bright red (oxyhaemoglobin).
However, for tissues oxygen leaves the blood at tissues and diffuses through extracellular fluid and then into cells.
wall structure of a blood vessel: outer layer
3 layers all together
Tunica adventitia ( externa):
Outer layer
strong connective tissue
resits pressure
Wall structure of a blood vessel: middle layer
Tunica media:
middle layer
smooth muscle
middle layer allows vasoconstriction and vasodilation to happen.
Wall structure of a blood vessel: Inner layer
Tunica interna:
Inner layer
endothelial cells
allows blood to flow smoothly.
Why is the pulmonary artery different to other arteries?
Most arteries carry oxygenated blood away from the heart
Whereas, the pulmonary artery carries deoxygenated blood from the heart to the lungs ( still “away” ) .
What does the Poiseuille-Hagen formula show?
Shows that small changes to the radius of a vessels, could affect how blood flows.
What are the 2 main types of artery:
Muscular artery
Elastic artery
Muscular artery:
These type of arteries are normally between the elastic arteries and the capillaries
smooth muscle to contract or relax
which helps to adjust diameter of the lumen
blood flow is controlled through a capillary bed.
Elastic artery:
Largest diameter
These type of arteries are NEAREST to the heart.
Thick elastic layer allows flexibility to accommodate blood being pumped from the heart at high pressures.
Arterioles:
Arterioles are very small arteries.
arterioles can withstand blood pressure
- they contain smooth muscle.
What nervous system ( P or S) regulates the contraction and relaxation of arterioles?
Sympathetic nervous system.
capillaries:
very thin walled vessels.
One cell thick
- made of endothelial cells and basement membrane.
- have a very narrow lumen.
- capillaries are responsible for exchange between blood cells and tissues.
What type of vessles to cappillarries branch out into:
Venules
venules are tiny vessels
What are “postcapillary venules”
These form when capillaries join together.
walls of postcapillary venules are made up of endothelial cells with a few fibroblasts.
Fluids and leukocytes can pass through their walls.
What is formed when many venules join together?
A vein.
Veins:
Carry deoxygenated blood at low pressure to the heart.
Large lumen
thin walls.
Where and what type of blood does the pulmonary vein carry:
The pulmonary vein carries oxygenated blood from the lungs to the heart.
What is the vein made up of:
Thin tunica adventitia
Thin tunica media
smooth muscle
What is Venoconstriction:
contraction of smooth muscle in the vein.
What does venoconstriction help with
Helps with venous return.
( Rate at which blood flows back to the heart).
what layer of veins contain semi lunar valves:
The tunica interna.
semi lunar valves open and shut to prevent blood from flowing backwards.
What 2 factors positively affect “venous return”
1) Respiratory pump:
2) Muscle pumping: skeletal muscles contract around a vein,, which presses on a vessel wall
allowing blood to flow to the heart.
1) Respiratory pump (Venous return) :
thoriac veins expand, causing blood to be delivered to the right atrium faster.
Inhalation also increases abdominal pressure, causing blood to flow to the heart.
2) Muscle pumping:
skeletal muscles contract around a vein, which presses on a vessel wall
allowing blood to flow to the heart.
Systemic circulation:
Supplies blood to the entire body
(except lungs)
Pulmonary circulation:
supplies blood to the lungs.
What are the 2 parts of the lymphatic system?
1) Lymphatic vessels
2) Lymphoid tissue (plays a role in defence responses).
what does hydrostatic and osmotic pressure do ( lymphatic system) ?
Forces the fluid a out of capillaries ( at the arteriole end) and most of the fluid is reabsorbed ( at the venous end).
What do Lymphatic vessels do?
They collect excess fluid and return this fluid back to the blood.
What is it called once the fluid is inside the lymphatic vessel ?
the thing inside is then known as “lymph” .
Lymph capillaries:
Porous
found in most tissues
What is the lymphatic system thoo ?
Basically, its just a one way drainage system.
Where lymph flows back to the heart
via lymphatic vessels.
what do a group of lymphatic capillaries form ?
They unite to form “collecting vessels”,
These vessels then unite to form “trunks”,
these trunks unite to finally form “ducts”.
Difference between veins and collecting vessels ( Lymphatic system) ?
Collecting vessels have thinner walls than veins.
Difference between veins and lymphatic vessels ( Lymphatic system) ?
Lymphatic vessels have more valves than veins do.
what are the 2 lymphatic ducts ?
Right lymphatic duct
And the,
Left lymphatic duct.
Right drains the right side of the:
head
neck
arm
and right side of thorax.
Left drains: the rest of the body.
left duct BIGGER than right.
Lymph is then returned to the venous circulation at the junction of the internal jugular vein and subclavian vein on the left and right sides.
What is blood pressure:
Drives blood flow around the cardiovascular system.
Blood will flow from an area of high pressure to an area of low pressure.
When referring to the term “ blood pressure” what are we referring to ?
Systemic arterial blood pressure.
which is expressed as 2 numbers.
What are the meaning of the two numbers ( blood pressure)
E.g. 120/80 mmHg
First number is “systolic pressure”
Second number is “diastolic pressure”.
What is “blood flow” ?
The volume of blood flowing through a certain region.
What is peripheral resistance (also known as vascular resistance)
Resistance to blood flow.
3 factors that contribute to peripheral resistance:
1) Blood vessel length: longer length= increased resistance.
2) Blood viscosity: thicker blood: more resistance.
3) Blood vessel diameter ( difference in resistance between vasoconstricted and vasodilated vessels).
Which is more resistant to blood flow,
vasoconstricted or vasodilated vessels ?
vasoconstricted MORE resistance
vasodilated LESS resistance.
Cardiac output (CO) equation:
CO = HR x SV
CO = cardiac output (L/min)
HR = Heart rate (BPM)
SV = Stroke volume
DURING excercise, if HR or SV increase, then CO increases.
Cardiac output (CO) equation:
CO = HR x SV
CO = cardiac output (L/min)
HR = Heart rate (BPM)
SV = Stroke volume
DURING exercise, if HR or SV increase, then CO increases.
what 2 components form the cardiovascular centres ?
1) cardiac centre
2) vasomotor centre.
What’s the role of the vasomotor centre ?
The vasomotor centre receives inputs from baroreceptors,
To adjust the diameter of blood vessels.
Where is the vasomotor centre located ?
in the medulla oblongata
What are Baroreceptors and what do they do ?
Baroreceptors are sensory nerves
that monitor changes in BP.
They do this by sending signals to the medulla oblangata.
Where are baroreceptors found?
Found in the carotid sinuses
and
aortic arch.
How does an increase in BP affect vasoconstriction and HR ?
increase in BP causes a reduce in vasoconstriction and HR .
What types of baroreceptros increase HR ?
THe ones positioned above the heart
What type of baroreceptors decrease HR ?
The ones in level with or below the heart.
what molecule mediator is released if BP is too high ?
Atrial natriuretic peptide
causes atria to stretch
which causes kidneys to reabsorb less sodium and water.
vasodilation also occurs.
BP reduces.
What molecule mediator is released when BP is dangerously low ?
Antidiuretic hormone (ADH)
causes the kidneys to absorb more water.
Vasoconstriction occurs too.
BP increases.
What can inhibit the release of ADH ?
Ingestion of alcohol.
How can exercise affect BP ?
exercising changes levels of o2 and co2, which regulates BP via chemoreceptors.
What are the 3 different types of muscle tissue ?
1) Skeletal (striated).
2) cardiac muscle.
3) Smooth muscle (non-striated).
Skeletal muscle (voluntary or involuntary)
VOLUNTARY control.
Cardiac muscle
INVOLUNTARY control.
fibres are attached at their ends with intercalatediscs.
these intercalated discs contain gap junctions for quick conduction of action potentials.
Cardiac muscle
INVOLUNTARY control.
fibres are attached at their ends with intercalated discs.
these intercalated discs contain gap junctions for quick conduction of action potentials.
Smooth muscle
Non striated
thickest fibres
INVOLUNTARY control.
Diastole: is heart contract or relax.
relax
- blood is pumped into atria and ventricles.
systemic and pulmonary pressure respectively: 80 and 20 mmHg
Systole: is the heart contract or relax ?
contract.
-atria pumps blood into ventricles.
systemic and pulmonary pressure respectively: 120 and 40 mHg.
Electrical conductivity of the heart:
SAN is made up of “self-excitatory cells” that depolarise.
This depolarisation spreads around atrial tissue and to the AVN (atrioventricular node).
Action potential then travels down the bundle of his and purkyne tissue, causing the ventricles to contract.
Where is the SAN located ?
SAN ( sinoatrial node) is located in the right atrium
what is the boiling point of oxygen
-183 degrees celcius
MINUS 183 degrees celcius.
how many oxygen atoms in ozone ?
3
o3
what do the “conducting zones” do ?
They conduct air to sites of gas exchange.
What is the respiratory zone ?
This is where gas exchange occurs.
what does “olfactory mucosa” mean ?
It means sense of smell
Where does cillia in the nostrils move the mucus to ?
to the pharynx where it is swallowed.
pharynx also acts as the “resonance chamber” for our voice.
What nerves trigger sneezing to occur to expel irritants ?
Sensory nerves
why does a nose run in the winter ?
In cold environments cilia move a lot slower
which means more mucus remains in the nasal cavity.
What do “paranasal sinuses” do ?
help warm and moisten the air we inhale.
what is sinusitis ?
Inflammation of sinuses.
This could result in a sinus headache
What does the Larnyx do ?
Houses the vocal chords and keeps our airways open.
Diverts air and food down the tracheae and oesophagus.
What is the specific mechanism of the larynx that helps to prevent food from going down the tracheae ?
When swallowing a reflex occurs
causing the larynx to pull up
and the epiglottis to cover up the laryngeal inlet.
Why is smoking bad for the respiratory system ?
Destroys cilia.
which of the two bronchi is wider and shorter ?
The right bronchi.
in the lungs what do primary bronchi divide into ?
Secondary bronchi,
which then divide into tertiary bronchi.
then these tertiary bronchi keep dividing to form smaller and smaller bronchi.
what 2 mechanism alter airway resistance ?
Bronchoconstrictions and bronchodilations.
what 2 mechanism alter airway resistance ?
Bronchoconstriction and bronchodilation.
what types of capillaries are alveoli covered by ?
covered by pulmonary capillaries
the basal lamina of these capillaries and the alveoli are fused together.
(basal lamina provides support to epithelial cells)
what does the fluid that the type II cells in the alveoli wall secrete do ?
The fluid contains a surfactant,
which helps to reduce surface tension of the alveolar fluid
and prevents “alveolar collapse” .
what is the pleura ?
Thin double layered membrane that forms a closed sac.
What does pleural fluid released do ?
Acts as a lubricant allowing the lungs to easily move during breathing.
What 2 parts is the pleura split up into ?
1) parietal pleura
2) Visceral pleura
What are the four different types of inspiration and expiration ?
1) quiet inspiration
2) forced inspiration
3) quiet expiration
4) forced expiration
Quiet inspiration:
diaphragm relaxes
external intercostal muscles contract
lifting the ribs and moving the sternum forward.
increasing the volume of the thoracic cavity, lowering pressure
air is drawn into the lungs
Forced inspiration:
scalene and sternomastoid muscles
and the pectoralis muscles contract
this raises the ribs upwards even more
Also, the back extends to straighten the thoracic curvature (erector spinae muscles).
Quiet expiration:
Passive process
inspiratory muscles relax
volume of thoracic cavity decreases
forcing air out the lungs
Forced expiration;
wall of the abdomen contracts
increasing the intra-abdominal pressure
rib cage moves down and inwards
internal intercoastal muscles contract ( cause rib cage to move downwards).
how many “respiratory groups are there” ?
2
What are the 2 types of respiratory groups ?
Dorsal (DRG)
ventral (VRG)
Where are the DRG and VRG located ?
In the medulla
What happens to DRG in overdose of alcohol or opioids
DRG will stop
Respiration will stop
could go into coma
and could even be fatal
which respiratory group involves “forced breathing”
VRG
what do chemoreceptors monitor ?
co2 o2 pH
What is the partial pressure of Co2 in the arterial blood ?
40 +- 3mmHg
How can respiratory centres and ventrilation be stimulated ( via chemoreceptors) ?
Co2 from the blood diffuses into the cerebrosal spinal fluid and combines with water H2o to form carbonic acid ( HCo3)
this dissociates to form H + ions.
which lowers the pH
Low pH excites chemoreceptors to stimulate respiratory centres, increase in ventilation.
what is the normal range for partial pressure of oxygen ?
75 to 100 mmHg
If it goes below 60mmHg then there will be an increase in ventilation.
What is acidosis ?
Drop in pH
What is alkalosis ?
Increase in pH
What is microbiology ?
Study of the biology of microscopic organisms
Acellular def
Not containing cells
What are 3 differences between prokaryotes and eukaryotes ?
1) E has a nucleus but P does not
2) Undergo cell division in different ways
3) E has cytoskeleton but P does not
What type of cell division do prokaryotes undergo ?
Binary Fission
What type of cell division do eukaryotes undergo ?
Mitosis and Meiosis
When talking about gram positive and gram negative, what are we referring to ?
Bacterial cell walls
Difference between gram positive and gram negative ?
Gram positive is thicker than gram negative.
What is “capsid” ?
A protective protein coat during transmission
and may be involved in immune response.
Are “envelopes” present in all types of viruses ?
Nah
What do viruses need to replicate
They need a host cell
Do antibiotics affect viruses ?
Viruses are not affected by antibiotics
4 stages of “bacterial growth” ?
1) lag
2) log
3) stationary
4) Death
lag phase:
increased metabolic activity of cells due to the synthesis of enzymes.
log phase:
Exponential phase
Cell POPULATION
DOUBLES at regular intervals.
Stationary phase:
No increase or decrease in cell population
Death phase:
Decrease in the number of cells.
What is Binary fission ?
A type of asexual reproduction
(only one parent cell)
doesn’t involve gametes
3 Advantages of binary fission ?
Only need one parent cell
Rapid division
Daughter cells are clones of parent cells.
Disadvantage of binary fission ?
No genetic variation- change in environment could cause species to become extinct.
similarity between eukaryotes and prokaryotes ?
They both under go “ semi-conservative replication”
What is a “replisome” ?
A Large protein complex that carries out DNA replication.
State the 4 techniques used to introduce a foreign gene into host cells ?
1) Transformation
2) Transduction
3) Transferation
4) Conjugation
Transfection:
Introducing nucleic acids into cells via non-viral methods
Transduction:
where foreign DNA is introduced to the cell via a viral factor.
Conjugation:
When bacteria cells transfer their genetic material through direct contact.
Transformation:
Process of DNA uptake by bacteria from the surrounding environment.
What does transgenic mean ?
Organism whose genome has been altered by foreign genetic material from another species.
What type of decomposers are bacteria ?
primary decomposers
They recycle nutrients.
What are “probiotics” ?
Good bacteria that keep you healthy and prevents pathogens from gaining access to the body.
Bioremediation:
Decontamination hazardous wastes.
where microbes clean up the environment.
What is dissemination ?
Exit from host
What are the 3 types of transmission routes (contact) ?
1) Direct
2) indirect
3) airborne
The 3 main routes of disease transmission ( Human to human) :
1) Respiratory route
2) The faecal route
3) The venereal route
What is the definition of “infectious dose” ?
Number of infectious organisms required for 50% of the population to show signs of infection.
What can viruses be classed as ?
Obligate parasites ( they need a host to survive to make more viruses) .
2 ways that the disease can interact with an organism :
1) Direct; producing microbial toxins that kill immune system cells.
2) Indirect: interactions with the host immune response. (inflammation. puss formation etc).
What are the 2 types of microbial toxins:
Endotoxins and exotoxins.
Properties of Endotoxins:
1) Heat stable
2) Lipopolysaccharide ( LPS) - Lipid A 0 gram positive
3) May stimulate immune reaction
4) can cause chills, fever, muscle weakness and aches and pains.
Properties of Exotoxins:
1) Soluble
2) prone to heat
3) exotoxins have systemic effects
4) can be carried in plasmids
5) can act as targets for vaccine design. ( toxoids)
What are “toxoids” ?
Things that can act as targets in the process of designing a vaccine.
what is tetanus
A disease that causes “ systemic intoxication”
What is tetanus caused by ?
CAused by clostridium tetanus
What does clostridium tetanus actually do ?
Contaminates deep wounds where oxygen concentration is low.
What does tetanospasmin do ?
Blocks nerves
and blocks release of the neurotransmitter GLYCINE
causing muscle spasms
and reduces contraction of muscles.
Cholera:
Water disease, found in contaminated water.
Is cholera gram negative or positive ?
Gram negative
What does the cholera toxin actually do to cells ?
1) toxin is secreted and enters cells
2) This affects c-AMP
3) Decreases the amount of fluid and electrolytes in the body
4) Leading to fatal dehydration
What is epidemiology ?
Study of people and disease throughout time.
What is a sporadic disease ?
A disease that occurs at irregular intervals
What is an endemic ?
A disease that maintains a regular low level in a population.
What are the 5 methods of sterilisation ?
1) Filtration (removal) - 2 types ( Dry and wet)
2) Heat (Destruction)
3) Gaseous sterilisation (Destruction)
4) irradiation (Destruction)
5) Chemical (Destruction)
What is D value ?
TIME TAKEN at a specific temperature, to achieve a 90% reduction in the number of cells.
What is Z value:
INCREASE IN TEMPERATURE needed to reduce the D value by 90%
Antibiotic definition ?
A substance produced by a microorganism or by chemical synthesis, which at low concentrations can kill or inhibit the growth of other microorganim.
What is “ selective toxicity” ?
When only the microbe is affected
What does bactericidal do (C) ?
Kills or breaks down bacteria.
What does bacteriostatic do (S):
INHIBITS GROWTH of bacteria (reversible effect).
Types of metabolic reactions antibiotics are involved in ?
1) Folate metabolism
2) DNA synthesis
3) RNA synthesis
4) Protein synthesis
What do “ Beta- lactams” do ?
Strengthen the stability of the membrane.
Where do beta lactams come from ?
Antibiotics can make them
What are the 3 different types of antibiotic RESISTANCE mechanisms :
1) Altering Targets
2) Destroying antibiotics
3) modifying antibiotics
3 ways antibiotic resistance can occur :
1) Over prescribing
2) Non-complinat
3) Not using the antibioitc for its intended purpose
3 ways to overcome antibiotic resistance:
1) Identification of the pathogen
2) Selection of the antimicrobial agent appropriate for the pathogen
3) Drug combinations may help overcome the antibiotic resistance.
What is non specific immunity ?
First line of defence after the host is first exposed to the pathogen.
What are the 2 different types of immune systems ?
1) The innate immune system
2) The adaptive immune system
What are the 4 defensive barriers of the innate immune system ?
1) Anatomic
2) Physiologic
3) inflammatory
4) Phagocytic
What are 3 examples of anatomic barreirs ?
Skin and sebaceous glands and mucous membranes.
Skin as an anatomic barrier:
Rarely penetrated by bacteria
“flora” of the skin metabolises substances which are secreted onto the skin,
and produces fatty acids.
Sebaceous glands as an anatomic barrier:
They produce sebum.
What does “sebum” do ?
Consists of lactic and fatty acids
which help maintain a pH of 3-5.
This pH inhibits the growth of most organism.
Where are mucous membranes found ?
Respiratory tracts.
what type of cells secrete mucus ?
Epithelial cells
What are the 3 main factors of physiologic barriers:
1) temp
2) pH
3) Solubility
Example of an innate physiologic barrier:
Gastric acidity
How gastric acidity acts as a defence mechanism ?
Very low ph in the stomach = organisms cant survive.
One reason new borns might be more susceptible to disease than adults ?
This is because new-borns stomach pH are not as low as adults yet.
What are lysosomes ?
Hydrolytic enzymes
Where are lysosomes found ?
In mucus secretions and tears.
What some examples of phagocytic barriers ?
Monocytes, neutrophils, eosinophils, macrophages can digest microorganism in the “phagolysosome” .
How might inflammation occur ?
A microbe may trigger an inflammatory response via ana interaction with cell surface receptors
What 2 things is inflmmation related to :
Cell regeneration and scarring
What are the 2 types of inflammation ?
Acute inflammation and chronic inflammation.
Acute inflammation:
can last anywhere from a few minutes to a few days
characterized by fluid and proteins.
Chronic inflammation:
Can last anywhere from weeks to years
characterized by lymphocytes and and macrophages.
What are the key features of inflammation:
Vasodilation
Endothelial permeability
Extravasation ( Leakage)
What are the 5 signs of inflammation ?
1) heat = caused by vasodilation
2) redness = caused by vasodilation
3) swelling = caused by vascular permeability
4) Pain = caused by mediator release
5) loss of function = caused by mediator release
What is “margination” in regards to blood vessels ?
Means “close to wall of blood vessel”
How is thee fluid like substance “pus” formed ?
Formed by an accumulation of dead cells and digested material and fluid.
What are the 2 types of inflammatory mediators:
1) cell derived mediators
2) plasma derived factors
3 examples of cell derived mediators:
1) Arachidonic acid derivatives
2) Cytokines
3) Vasoactive amines
What do arachidonic acid derivatives do ?
Cause increased capillary permeability, vasodilation and smooth muscle constriction.
What can cytokines do in the inflammatory response ?
Attract inflammatory cells such as neutrophils
What does histamine do in the inflammatory response ?
A chemical that is released in response to tissue injury,
that binds to receptors causing vasodilation and increasing permeability of capillaries and vessels.
What are the 4 different types of plasma derived factors:
1) Acute phase proteins
2) Kinin system
3) Clotting
4) Complement
What is an example of an acute phase protein ?
CRP
its produced by the liver
useful inflammatory marker
What are kinins:
Small peptides involved with inflammatory response.
Where are “kinins” present ?
In the blood plasma when its in its “inactive form”.
What do “kinins” do ?
Activate in response to tissue injury permeability of capillaries
causes vasodilation and increased
What type of kinin stimulates pain receptors ?
Bradykinin
What do enzymes in the “blood-clotting” system do ?
Activate an enzyme cascade that results in deposition of insoluble strands of fibrin.
What do fibrin strands do in the “blood clotting” system ?
Wall off injured area and prevent spread of infection.
What happens after inflammation has occurred ?
once the inflammation has stopped and debris has been cleared
tissue repair begins
capillaries grow into the fibrin of a blood clot
Fibroblasts ( connective tissue cells) replace the fibrin as the clot dissolves.
as fibroblasts and capillaries accumulate scar tissue forms,
How is scar tissue formed ?
Accumulation of fibroblasts and capillaries.
What is “abscess” with regards to inflammation ?
A walled off collection of pus
What are vaccines ?
Dead or genetically engineered antigens that defend against harmful microorganisms.
How do vaccines actually benefit as a defence against harmful microorganisms ?
They promote the development of antibodies, preventing the development of disease.
What are the 4 main types of vaccines ?
Whole organism vaccine ( Attenuated vaccine)
INactivated vaccine
Recombinant antigen vaccines
Recombinant vector vaccine
What is pathogenicity ?
The ability of a pathogen to cause disease
Disadvantage of attenuated vaccine ?
Less pathogenicity
But vaccine can grow within the host
Why may there usually be no need for boosters ?
Due to increased immunogenicity
And increased memory cell production
What’s safer inactive or active vaccine ?
Inactive
How are pathogens that are used in inactive vaccines actually “inactivated” ?
By heat or chemicals.
What some examples of purified macromolecules ?
Polysaccharide vaccines
What is special about polysaccharide vaccines ?
They only activate B cells.
What do polysaccharide vaccines produce ?
IgM with little or no memory cells.
(Immunoglobulin G)
What is one advantage of a polysaccharide vaccine ?
They can be conjugated into a protein carrier ( E.g. transport proteins)
What does “recombinant antigen vaccines” involve ?
Involves DNA coding for the relevant antigen to be expressed as a suitable vector.
An example of a recombinant antigen vaccine ?
Hepatitis B vaccine, where the gene for the major antigen is CLONED in yeast cells.
Antigen vaccine helps the release of antibodies.
Recombinant vector vaccines
Genes coded for antigen are inserted into the genome of the attenuated pathogen.
With regards to ‘recombinant vector vaccines”, if the gene is coding for envelop protein what happens?
If a gene is coding for envelope protein a cell mediated and antibody response can be generated.
What are the 2 different types of immunisation ?
Active and passive immunisation
What is passive immunity ?
Transfer of antibodies and immune cells to the patient.
What is a key feature of “passive immunity”
immune response is no produced
memory cells is not produced
What is an example of natural passive immunity ?
placental transfer of maternal antibodies
What is an example of artificial passive immunity ?
antibodies directly into the body.
One draw back of passive immunity ?
BOOSTERS required
due to the persistence of “maternal antibodies” ,
which can block epitotes.
One draw back of passive immunity ?
BOOSTERS required
due to the persistence of “maternal antibodies” ,
which can block epitopes.
What is active immunisation ?
stimulating a primary immune response
which involves T and B cells
Leading to production of memory cells,
which can cause a faster secondary immune response upon exposure to a pathogen.
What is an example of natural active immunisation ?
CHICKENPOX
( Generation of memory cells following a childhood infection)
What is active artificial immunity ?
Vaccines.
What is the primary aim of vaccine design ?
To induce a memory response
During vaccine design, what do you have to do to make sure “ t helper cells “ get involved with the situation ?
Antigens should be processed by APC’s
in order for “T h cells to activate “
What are the 2 main functions of the kidneys ?
1) to reabsorb water
2) To remove waste products from the blood
What does helicase do ?
Catalyses unwinding of DNA
What does Topoisomerase do ?
Introduces negative coils into the DNA,
which helps compensate the torsional strain caused by the unwinding of the DNA double helix during DNA replication.
What is the order of heart elictrac conduction activity ?
1) SAN
2) Atrial myocardium
3) AVN
4) Bundle of His
5) purkyne fibres
6) Ventricular myocardium
