Overview of Science for Medicine Flashcards
What is aetiology?
The cause of the disease
What is pathogenesis?
How the disease develops
What is a sign?
What the doctor sees
What is a symptom?
What the patient experiences and tells you
What is a diagnosis?
Determining the nature and cause of disease or injury
What is a prognosis?
A prediction of the probable outcome of the disease
What are the 6 classifications of disease?
Growth Inflammation Degenerative Developmental Circulatory Unnatural
What percentage of ECF is ISF?
80%
What percentage of ECF is plasma?
20%
What is negative feedback?
When a change to the system is detected and the feedback works to counteract this change and restore the system back to normal
Why is the feed forward system more sophisticated?
Because the changes can be anticipated before the significant changes have happened
What fraction of body water is in the ECF?
1/3
What fraction of body water is in the ICF?
2/3
Can energy be destroyed?
No energy can be converted from one form to another but cannot be created or destroyed
What do all energy transformations lead to?
An increase in disorder in the system
An increase in entropy
Why is it unusual that there is an increase in entropy for cells?
Because cells create order
What do cellular processes release that creates more disorder in the system?
Heat
What is metabolism?
The chemical processes in a living organism that allow food to be used for tissue growth
What is metabolism a mix of?
Summative and degradative reactions
What is another name for degradative reaction?
Catabolism
What is another name for summative reactions?
Anabolism
Do catabolic reactions have a positive or negative ve?
Negative
-ve
Do anabolic reactions have a positive or negative ve?
Positive
+ve
What is the energy obtained from catabolic reactions used for?
It is used up in anabolic reactions to produce more highly ordered compounds
What is the general function of NADP, NAD and FAD?
They are use in redox reactions as electron carriers
What do ATP and ADP act as?
Free energy carriers, that couple anabolic and catabolic reactions
How does ATP/ADP couple anabolic and catabolic reactions together?
Using phosphate group transfers
What are the major elements used to construct human biomolecules?
Oxygen Carbon Hydrogen Nitrogen Sulphur Phosphate Sodium Potassium Chlorine Calcium
What is meant by cis?
Functional groups on the same side
What is meant by trans?
Functional groups on opposite sides
Why are functional groups on molecules so important?
They affect the interactions of that molecule with other molecules
What is the configuration of a molecule?
The fixed arrangement of atoms in a molecule
What is the conformation of a molecule?
The precise arrangement of atoms in a molecules
What are the 5 chemical reactions that occur in living organisms?
Redox Making/breaking C bonds Group transfers Condensation/Hydrolysis Internal Rearrangements
Describe redox reactions
When electrons are gained and lost in reduction and oxidation reactions
Usually how many electrons are gained or lost in redox reactions?
2
What is an internal rearrangement reaction?
When the molecule is rearranged to give it different properties and a different structure
What is a group transfer reaction?
When a functional group is transferred from one molecule to another
What is a condensation reaction?
The joining together or monomers or molecules usually yielding water
What is a hydrolysis reaction?
The breaking down/separation of joined together molecules sing water
What 2 compartments are cells divided into?
Nucleus
Cytoplasm
What is the cytosol?
The organelles and the fluid
What does the nucleus contain?
DNA, nucleoproteins and some RNA
What do the nucleoli serve as sites for?
Ribosomal RNA synthesis and Ribosomal assembly
What is the function of rough ER?
Synthesises and secretes/packages proteins
Why does rough ER have a studded appearance?
Due to the presence of ribosomes
What is smooth ER responsible for?
Lipid biosynthesis
Membrane synthesis and repair
What is the function of ribosomes?
They carry out protein synthesis
What is the function of the golgi apparatus?
To package and process secretory proteins
Also synthesis complex polysaccharides
What does a lysosome contain?
Powerful digestive enzymes
What do lysosomes act as?
Cellular stomachs
What is the folded inner membrane of mitochondria known as?
Cristae
What is mitochondria vital for?
Energy production
Citric Acid cycle
Electron transport chain
Are mitochondria mobile cells?
Yes
What is the role of the cytoskeleton?
Provides strength and support while also allowing for cell motility
What do microfilaments form that line the small intestine?
Microvilli
What do microtubules form that line the respiratory tract>
Cilia
What structure do microtubules form that are useful during cell division?
Spindle fibres
Why is water a polar molecule?
Due to the difference in E.N between oxygen and hydrogen
The oxygen is particularly E.N
Between what elements does H bonding occur?
H-F
H-O
H-N
Are molecules that form H bonds water soluble?
Yes
When a water soluble compound is added to water what are the water-water bonds replaced by?
Water-solute
Are uncharged molecules soluble?
No
How do uncharged molecules arrange themselves in water?
They form cages
Why do uncharged molecules form cages?
To minimise disruption of the surrounding water molecules
What is meant by the term amphipathic?
The molecules contains both hydrophobic and hydrophilic parts
Give an example of an amphipathic molecule
Phospholipids
Have hydrophilic head
Have hydrophobic tail
What is pH a measure of?
H+ conc.
What equation measures pH?
pH -log(H+)
What is a buffer a solution of?
A weak acid
What happens to strong acids in solution?
They fully dissociate
Why is it that weak acids can only form buffers?
Because they are only partially dissociated meaning they can dissociate more and less to compensate for the disrupted pH
What happens to weak acids in solution?
They do no dissociate very much
What is the cell membrane made up of?
A phospholipid bi-layer
How would you describe the permeability of the cell membrane?
Selectively permeable
Can permeability of the cell membrane vary?
Yes depending on the needs of that cell at that time
Why is the cell membrane very flexible?
Due to fatty acids
What does the membrane provide binding sites for?
Chemical recognition
What are the 2 classes of membrane proteins?
Integral membrane proteins
Peripheral proteins
Why are integral proteins amphipathic?
Because they span the full membrane which is also amphipathic
How do integral proteins act as channels?
They create a passage for which ions can cross the membrane
How do integral proteins act as carriers?
They transport substances across membranes acting like pumps
How do integral enzymes act as carriers?
They create binding sites at the surface which interact with intercellular pathways
How do integral enzymes act as receptors?
They act as recognition sites for chemicals and signals
What % protein content do mitochondria have?
Around 75%
What % protein content do schwann cels have?
18%
What % protein content do most cells have?
Around 50%
Are peripheral proteins amphipathic?
No
From what side do peripheral proteins make contact with the plasma membrane?
From the intercellular side
What is meant by diffusion?
When molecules spread out from an area of high concentration to an area of low concentration - when the membrane is permeable to the molecule
To diffuse through the lipid bilayer what do molecules need to be?
Small
Uncharged
Hydrophobic - lipophilic
What type of membrane channel does water flow through?
Aquaporin
What is a voltage gated channel?
One which will change conformation in response to a change in electrical potential
What is a ligand gated channel?
One which will change conformation in response to a ligand binding
What charge does the inside of the cell have in relation to the outside of the cell?
negative
What is facilitated diffusion?
Transports of solutes down their conc. gradient requires a change in conformation but needs no direct energy source
What is active transport?
When energy is require to move substance against their conc. gradient. The energy comes from ATP
Where does the energy for active transport come from?
ATP
What is osmolarity a measure of?
Solute concentration
What does 1M of glucose have an osmolarity of?
1 osmole/L
What does 1M of NaCl have an osmolarity of?
2 osmole/L
What determines the cell volume?
Tonicity
If the ECT has a higher tonicity than the ICF what happens?
The solution is hypertonic
The cell will shrink as water leaves via osmosis to compensate
If the ECF has a lower tonicity than the ICF what happens?
The solution is hypotonic and the cell will swell as water enters the cell via osmosis to compensate
What is an isosmotic solution?
One in which there is an equal number of both penetrating and non-penetrating solutes on either side of the membrane
What is an isotonic solution?
One which there is an equal number of non-penetrating solutes on either side of the cell membrane
What happens in endocytosis?
When there is an invagination of the membrane to form a vesicle around the target substance to engulf it into the cell
What happens in exocytosis?
When a vesicle containing the substance is released from the cell
What is the function of epithelial tissue?
To cover surfaces and separate compartments
What do tight junctions do?
Seal intracellular space
Make waterproof
What do gap-junctions do?
Allow passage from cytoplasm to cytoplasm
Allowing cell to cell communication
What is a desosome?
An adhering junction
Cell to cell junction
That provides firm anchorage
What is a hemidesmosomes?
A cell to ECM junction
What does the function of epithelial tissue depend on the cell or ECF?
Cell
What function do cilia have?
Movement
What function do microvilli have?
Absorption
What cells are found in the liver?
Hepatocytes
Give an example of a function of hepatocytes?
Secretion
How are kidney cells arranged?
Into nephrons
Give some examples of functions of nephrons
Filtration of blood
Partial absorption of filtrate
Where do endocrine glands secrete to?
The blood
Where do exocrine glands secrete to?
The surface
Give an example of a exocrine gland
Sweat glands
What shape does a tubular glands have?
Tube
What shape does a acinar gland have?
Rounder
What is the consequence of abnormal over production of glandular function?
Pituitary giantism
What is the consequence of abnormal under production of glandular function?
Pituitary dwarfism
What percentage of body weight does collagen make up?
30%
How much can elastic fibres stretch?
1.5 times their length
Why is the skin an organ?
Because it contains all 4 types of tissue
What is the largest organ in the body?
The skin
What 3 layers is the skin composed of?
Epidermis
Dermis
Hypodermis
What is the epidermis composed of (tissue wise)?
Epithelium
What is the dermis composed of?
Connective tissue
What is the hypodermis composed of?
Fat
What is the function of the epidermis?
To form the boundary between internal and external environments
What is the function of the dermis?
To give structural strength
How many layers are there in the epidermis?
5
What are the 4 layers of the epidermis?
Stratum germinativum
Stratum Spinosum
Stratum granulosum
Stratum Corneum
What is the stratum germinativum bound to the basement membrane by?
hemidesmosomes
What is the stratum germinativum bound to other cells by?
Desosome
What is the stratum granuosum defined by the presence of?
Keratohyalin granules
Which layer of the epidermis is hard to identify?
Stratum corneum
Does the stratum corneum have cell organelles?
No
Does the stratum germinativum have cell organelles?
Yes - regular assortment of cell organelles
What 2 layers is the dermis composed of?
Papillary layer
Reticular layer
What type of connective tissue is the papillary layer composed of?
Loose connective tissue
What type of connective tissue if the reticular layer composed of?
Dense irregular connective tissue
Where is the stretch reflex found?
In all muscles
What is the simplest reflex?
Stretch reflex
What is an example of a stretch reflex?
The knee jerk reflex
What is the stretch reflex elicited by?
A sharp tap to the tendon
Why do tendons not contract?
Because they are inelastic
Where is the force from a sharp tap to the tendon transferred to?
Muscle fibres
What are the functions of bones in the body?
Mechanical
Protective
Metabolic
Haematopoies
What do bones provide support and attachment for?
Muscles
Tendones
Ligaments
Joints
What do bones protect?
Internal organs
What metabolic functions do bones have?
Mineral reservoir for calcium and phosphate homeostasis
In endochondral ossification where do bones form?
As cartilage
In intramembranous ossification what do bones form as?
A fibrous plate
Is there a cartilaginous phase in intramembranous ossification?
No
What invade the cartilage framework in Endochondral ossification?
Blood vessels
Osteogenic cells
What % of bone is composed of water?
20%
What % of bone is protein?
35%
What are the epiphyses of long bones composed of?
Trabecular (spongy) bone
How is cortical (hard) bone arranged?
In haversian systems
What gives bone it strength?
The collagen molecules form fibrils, which then form fibres and finally sheets
What are osteoclasts responsible for?
For resorbing cells
What are osteoblasts responsible for?
For laying down more bone
Why are bones constantly remodelled?
To keep them at peak strength
What are osteocytes derived from?
The differentiation of osteoblasts
What do osteocytes act as?
Sensors of mechanical pressure and damage
What are the 4 basic categories of amino acids?
Acidic
Basic
Uncharged polar
Non-polar
Give examples of functions of proteins
Movement Protection Transport Enzymes Receptors Structural Storage Hormones Control of gene expression
What is the primary structure of a protein?
The sequence of amino acids in a polypeptide chain
What is the secondary structure of a protein?
The spatial arrangement of amino acid residues - involves H bonding of the backbone
What are the 2 arrangements in secondary structure?
Alpha helices
Beta pleated sheets
What is the tertiary structure of a protein?
The interactions between the R groups of amino acids
What interactions can occur between the R groups in amino acids?
Van der Waals Ionic Interactions Hydrogen bonding Disulphide bridges Hydrophobic structures
What is the quaternary structure of a protein?
When there is the interaction of more than one protein subunit
What is a co-factor?
A non-protein component needed for activity
What is a co-enzyme?
A complex organic molecule usually formed from vitamins
What is a prosthetic group?
A cofactor covalently bound to the enzyme or very tightly associated with the enzyme
What is an apoenzyme?
The protein component of an enzyme containing the prosthetic group
What do enzymes increase?
The rate of a spontaneous reaction
What do enzymes lower?
The activation energy of biochemical reactions
What do enzymes accelerate the movement towards (but not change the position of)?
Equilibrium
What does a large Km tell us about the affinity of the ES complex?
A less stable ES complex
The S has a low affinity for the active site
What does a low Km tell us about the affinity of the ES complex?
That there is a more stable ES complex
The S has a high affinity for the active site
What does the Km value tell us?
The affinity of the substrate for the active site
Where do competitive inhibitors?
The active site
How do competitive inhibitors bind?
Non-covalently
Where do non-competitive inhibitors bind?
To a site other than the active site of the enzyme
How do competitive inhibitors affect the Km?
Increase the Km as the affinity for the proper substrate decreases
How is competitive inhibition overcome?
By increasing the substrate concentration
Can non-competitive inhibition be overcome?
No
What happens to Vmax in non-competitive inhibition?
The inhibitor cannot be displaced by increasing the conc. of the substrate so Vmax will decrease
What can metabolites binding to allosteric enzymes act as?
Inhibitors or activators
What is the concerted model of allosteric enzymes?
Each subunit exists in 2 different conformation
One is open (low Km)
One is closed (high Km)
With no substrate the enzyme flips between comformation
When 1 substrate binds it holds the enzyme in the open conformation
What is the sequential model of allosteric enzymes?
There is no flipping
The binding to one subunit causes a conformation change to the next
And so on…
What are the 3 major monosaccharides?
Glucose
Galactose
Fructose
What are the 3 major disaccharides?
Maltose
Sucrose
Lactose
Where is glucokinase found?
In the liver
Where is hexokinase found?
In all the other tissues
What are glucokinase and hexokinase to each other?
Isoenzymes
What are isoenzymes?
Enzymes that catalyse the same reaction
Are the Km and Vmax of hexokinase and glucokinase the same?
No they differ
When will glucokinase pick up glucose?
When the glucose conc. is high
Describe the Km and Vmax of hexokinase
Has a low Km
Low Vmas
Why does hexokinase have a low Km?
So that glucose will bind even at low concentrations
Why does hexokinase have a low Vmax?
As it means the tissues it is found in are quickly satisfied
Why does glucokinase have a high Vmax?
So it can trap as much glucose as possible
What is glycogen?
A polymer of glucose
What enzyme synthesises glycogen?
Glycogen Synthase
How is glycogen formed?
Glucogenin starts by binding to glucose from UDP-glucose to form chains of approx 8 subunits
Between what alpha are the branches in glycogen?
a1-a6
How often are the branches in glycogen?
Every 8 to 12 residues
What is the net gain of ATP for every 1 molecule of glucose in glycolysis?
2 ATP
What organelle dor RBC not have?
Mitochondria
What are the 2 phases of glycolysis?
Investment stage
Pay off stage
How many ATP are invested in the investment stage?
2ATP
How many ATP are gained in the pay off phase?
4ATP
What is the end product of glycolysis?
Pyruvate
How many stages are there in glycolysis?
10
What is the 1st stage of glycolysis?
Phosphorylation of glucose
What is the 2nd stage in glycolysis?
The conversion of G-6-P to F-6-P
What is the 3rd stage of glycolysis?
Phosphorylation of F-6-P to F-1, 6-bisP
What is the 4th stage in glycolysis?
The cleavage of F-1,6biP
What is the 5th stage of glycolysis?
The interconversion of triose sugars to give 2 of the same molecule
What is the 6th stage in glycolysis?
Oxidation of G-3-P to 1,3-bisPG
What is the 7th stage of glycolysis?
The P transfer from 1,3-bisPG to ADP
What is the 8th stage in glycolysis?
The conversion of 3-PG to 2-PG
What is the 9th stage in glycolysis?
Dehydration of 2-PG to PEP
What is the 10th stage of glycolysis?
The transfer of P from PEP to ADP
Why does NAD+ need to be regenerated?
Because it is needed for glycolysis q
What doe NAD+ act as?
An electron acceptor
What are the 3 fates of pyruvate?
Can enter the CAC to produce CO2 and water
Can be converted to lactate
Can be converted to ethanol (this occurs in yeast)
What does the fate of pyruvate depend on?
The needs of the cell at any given time
What is the main organism that converts pyruvate to ethanol?
Yeast and other micro-organisms
NOT IN HUMANS
What is regenerated in converting pyruvate to ethanol?
NAD+
When is pyruvate converted to lactate?
When the human cells are lacking O2
How is pyruvate reduced to lactate?
Via fermentation
What is regenerated in converting pyruvate to lactate?
NAD+
How is NAD+ regenerated in the conversion of pyruvate to lactate?
The oxidation of NADH drives the recdution of pyruvate to lactate
What do cells require for pyruvate to enter the CAC?
Oxygen
What is pyruvate oxidised to form when entering the CAC?
Acetyl coenzyme A
Where does the CAC occur?
Within the mitochondria
What is bond between sugar monomers called?
Glycosidic bond
Give example of tissues that rely entirely on glucose as their main energy source?
Brain
NS
RBC
Testes
What is gluconeogenesis not a reverse of?
Glycolysis
How many of the glycolysis reactions are reversible?
7 out of 10
What prevents the reactions in glycolysis being reversible?
Large -ve
How many reactions are there that can bypass the irreversible ones in glycolysis?
4
How is pyruvate converted back to PEP?
Pyruvate - oxaloacetate - maltate - oxaloacetate- PEP
How is lactate converted back to PEP?
Lactate- pyruvate - oxaloacetate - PEP
What does reaction A of gluconeogenosis do?
Converts pyruvate to oxaloacetate
What does reaction B of gluconeogenesis do?
Converts oxaloacetate to PEP
What is converted to what in reaction C of gluconeogenesis?
F-1,6-BP to F-6-P
What is happening in reaction C of gluconeogenesis?
Their is a dephosphorylation
In reaction D of gluconeogenesis what is converted to what?
G-6-P is converted to glucose
What is happening at reaction D of gluconeogenesis?
Their is a dephosphorylation
Why is the conversion of F-6-P to G-6-P usually the end point for gluconeogenesis?
Because ending the pathway here allows the cells to ‘trap’ the glucose
Which two sugars can enter glycolysis at various points?
Fructose and Galactose
Where is most fructose metabolised?
In the liver
What does the pentose phosphate pathway produce?
NADPH
What are pentoses (5-C sugars) precursors for?
ATP, RNA and DNA
What is NADPH used for in the liver?
Fatty acid synthesis
What is NADPH used for in the mammary gland?
Fatty acid synthesis
What is NADPH used for in the adrenal cortex?
Steroid synthesis
What is NADPH used for in RBC?
As an antioxidant
How many phases does the pentose phosphate pathway have?
2
Is ATP consumed or produced in the pentose phosphate pathway?
No
What does the 1st phase of the pentose phosphate pathway produce?
NADPH
What does the 2nd phase of the pentose phosphate pathway do?
Interconverts G-6-P and pentose phosphate to form lots of different 3,4,5,6 and 7-C sugars
What does NADPH link?
Catabolic and anabolic pathways
What is NADP+ used as?
An electron carrier
What does drinking lead to an increased what?
Blood lactate
What does drinking lead to a decreased what?
Blood glc
What does drinking inhibit?
Gluconeogenesis
Why does drinking inhibit gluconeogenesis?
Because to breakdown the ethanol NAD+ is needed
But the liver needs all of this NAD+ for gluconeogenesis
How does galactase join glycolysis?
Through conversion to glucose-1-phosphate by UDP
What is the citric acid cycle also known as?
The krebs cycle
Where does the CAC occur?
In the mitochondrial matrix
What does the CAC pass onto?
The electron transport chain
Does the CAC yield more or less energy than glycolysis?
More
What is the CAC a gateway to?
Aerobic metabolism
What is formed in the CAC?
NADH and FADH2
What enters the CAC?
Acetyl CoA
What are oxidised to produce acetyl CoA?
Pyruvate and FA
What enzyme converts pyruvate to Acetyl CoA?
Pyruvate dehydrogenase
Where is the only site of oxidative phosphorylation in eukaryotes?
Mitochondria
What does the mitochondria utilise to produce ATP?
Proton gradients
What are the folds in the mitochondria called?
Cristae
Where is the majority of NADH and FADH2 produced?
In the mitochondrial matrix
Where is a little NADH made?
In the cytoplasm
Why is the glycerol phosphate shuttle necessary?
Because NADH is unable to cross the mitochondria membranes
How does NADH eventually cross the mitochondrial matrix?
By passing its electrons onto FADH2
What does complex 1 of the ETC work on?
NADH
What happens at complex 1 of the ETC?
NADH is oxidised and its electrons are given to ubiquinone to give ubiquinol
What does ubiquinol do at complex 1 of the ETC?
Pumps H+ ions into the inter membrane space
What does the 2nd complex of the ETC work on?
FADH2
What happens at complex 2 of the ETC?
Ubiquinone becomes ubiquonol
What is another name for ubiquinone?
Q10
Co-enzymeQ10
What happens at complex 3 of the ETC?
E- taken from ubiquinol and passed onto cytochrome C
What does the cytochrome C do at complex 3 of the ETC?
Pumps protons into the intermembrane space
What does complex 4 of the ETC do?
Takes the e- from cytochrome C and passes them to molecular O2
Does complex 4 of the ETC pump protons across the intermmebrane space?
Yes
What complexes of the ETC pump protons across the intermembrane space?
1,3,4
What is overall created at the ETC by the pumping of electrons?
A proton gradient
What eventually happens to the protons in the intermembrane space?
They eventually flow down their concentration gradient back into the matrix of the mitochondria
How does H+ flow back down its conc. gradient?
By ATP synthase
What reaction is the energy stored in the proton gradient used to convert?
ADP + Pi to ATP
What is the final step in metabolising the food we eat?
The ETC
Where doe ADP and Pi enter in ATP synthase?
The beta subunit
What does the rotation of the Fo cyclinder cause?
Conformational change in the Beta subunits of F1
Causes to catalyse ADP to ATP
What are the 3 conformational changes in the beta subunit of ATP synthase?
B subunit that binds ADP and Pi
B subunit that binds ATP
B subunit that doesn’t bind ATP
What generates less ATP;NADH or FADH2
FADH2
To which complex of the ETC does NADH feed into?
Complex 1
To which complex of the ETC does FADH2 feed into?
Complex 2
Ultimately what are food molecules broken down to?
CO2 and H2O
What is the ETC coupled to?
ATP synthesis
What is malignant hyperthermia caused by?
Cause by leaky mitochondrial membranes that uncouple the ETC and ATP synthase
What is the thickness of the epidermis?
It varies around the body depending on its function
What do melanocytes form?
Skin pigment
What do merkel cells do?
Touch receptors
What do keratinocytes contain?
Keratin
What do keratinocytes extrude?
Lipids
What do the arrector pili muscles do?
Attach to hair follicle root
The hair straightens when the muscle contracts
What does the sebaceous gland secrete?
Sebum
Where does sebaceous secrete to?
Into the hair follicle
What is a good sign of overall health (a body part)?
The condition of nails
What contributes to thermoregulation?
Sweat glands
Blood vessel dilation
Hair
What is the repair tissue of skin?
Granulation tissue
Why do we get scars?
Because after damage the skin is not as composed and nicely put together as it was originally
Does one receptor always have one response?
No can have several responses
What are the range of receptor types?
Receptors that are also ion channels
That are enzymes
That directly regulate enzymes
That work via G-proteins
Does one cell have one type of receptor?
No it can have several receptors for different chemical signals
Are receptors needed for lipophobic or lipophilic transmitters?
Lipophobic
What is an ionotropic receptor?
Where the receptor is also an ion channel
What is the intracellular domain of enzyme receptors?
Kinase domains
What do kinase domains do?
Phosphorylate downstream cytoplasmic molecules
When receptors are coupled directly to ion channels what responses are generated?
Slow EPSPs
Slow IPSPs
What do receptors enable?
Specificity
What is an agonist?
Something that mimics the normal effect of the receptor
What is an antagonist?
Something that blocks the normal action of a receptor
What is the relationship between agonist concentration and effect?
As conc. of agonist is increases more receptors are occupied and therefore effect increases
What is the affinity for a drug?
The strength of chemical attraction between the drug and receptor
What is the efficacy of an agonist?
How good the agonist is at activating that particular receptor
Where are Ca2+ stores held?
Endoplasmic reticulum
What ion is a really good messenger?
Ca2+
What are some of the effects of Ca2+ as a messenger?
Directly affects target protein
I.e works on troponin
What is the effect of G protein being coupled to adenyly cyclase?
Increases or decreases cAMP
Activates or inhibits PKA
What is the effect of G protein being coupled to phospholipase C?
Produces diacylglycerol and inositol triphosphate
Activate PKC and releases Ca2+ from internal stores
What is a drug?
Any chemical agent that affects a biological system
What is the saturated response?
Maximum response
All receptors are saturated
What does the size of drug response depend on?
Affinity
Efficacy
Give an example of when antagonists are useful?
When they block pain receptors
What do selective agonists do?
Enhance a good effect
What do selective antagonists do?
Block a bad effect
What does the AP in the axon open at the pre-synaptic terminal?
Ca2+ channels
What does the opening of Ca2+ channels at the presynaptic terminal trigger?
The fusion of vesicles
Ach is released into the synaptic cleft
Where does Ach go in the synaptic cleft?
Diffuses across and binds to the receptors on post synaptic
What is the effect of Ach binding at the postsynaptic neuron (NMJ)?
Ligand gates Na+ and K+ channels are opened
What is the end plate potential?
The potential at the NMJ
What happens at the end plate potential?
It always reaches threshold so fires an AP
What is excess Ach in the synaptic cleft removed by?
Actycholinesterase
What is the first phase of the pentose phosphate pathway?
Oxidation of G-6-P to form lactone
NADPH is produced
What is the 2nd phase of the pentose phosphate pathway?
The interconversion to form lots of different 3,4,5,6 and 7 sugars
What is the golgi reflex the opposite of?
The stretch reflex
What does the golgi tendon reflex prevent?
Muscles contracting so hard that the tendon is torn from the bone
What is the golgi tendon reflex stiulated by?
Muscle contraction
What happens in the golgi tendon reflex?
There is an inhibition of the agonist (contracting muscle)
There is an excitatory of the antagonist (relaxing muscle)
Is the golgi tenodn reflex monosynaptic?
No
Polysynaptic
Are flexor reflexes polysynaptic
Yes
What can glutamate donate ammonia to?
Pyruvate to make alanine
Is a peptide bond planar?
Yes
What causes denaturation of proteins?
Heat, acids, solvents
What does denaturation cause?
Loss of biological activity
How is a prothetic group bonded?
Covalently
What is the holoenzyme?
The whole enzyme
What is specific for the active site?
The transition state
Is E+S = ES reversible?
Yes
What is the rte limiting step in enzymes?
Formation of product
What is Vmax?
Maximum velocity
What are ribozymes?
Enzymes made of RNA
What do enzymes in the wrong place generally indicate?
Disease
What is the combinations of CK?
BB
MM
BM
What is CK2 isoform a diagnostic marker for?
Myocardial infarction
What is random binding (enzymes)?
When the binding and release is random
What is sequential binding?
When the binding and release has to be in a specific order
What normally builds up and blocks in feedback inhibition?
End product
Blocks an enzyme in the pathway
What does GAG form (muco)?
Mucous
Synovial fluid
How is glucose absorbed in the villi?
Facilitated diffusion
Moves down with Na+ conc
What does glucose absorption indirectly require?
ATP to pump Na+ back out
Maintaining Na+ gradient
How is fructose absorbed?
GLUT 5
Why is Glc changed to G-6-P?
So cells can trap it
How is G-6-P trapped?
GLUT channels don’t recognise it
Is glycogen osmotically active?
No
Osmotically inactive
Do eosinophils contain granules?
Yes
On first exposure to an allergen what happens?
Makes lot of IgE antibodies
Receptors bind to mast cells
What is the most abundant complement protein?
C3
Are NK cells in innate or adaptive immunity?
Both
It is in both camps
What makes up the basement membrane?
Basal Lamina
Reticular Lamina
What are 2 examples of secondary functions of epithelium?
Movement
Absorption
Is simple epithelium one cell type?
No one layer but not one cell type
What is myoepithelial?
Epithelium that turns into muscle
What is an example of a steroid gland?
Adrenal cortex
What is the cell that forms collagen?
Fibroblasts
Why is glutamine transported in the blood not glutamate?
Because glutamine has no charge
And glutamate has a negative charge
What do desosomes link?
Keratin
What do adheren junction link?
Actin
Why is carbon so central in the human body?
Because of its versatility
What is the effect of a C=C bond?
Fixed arrangement
Can C-C rotate freely?
Yes
Where does digestion of Carbs start?
In the mouth
Does the stomach have any carb digestion?
No
