Obesity Flashcards
Describe primary and secondary active transport
Primary:
- uses energy source directly
- e.g sodium potassium pump
- obtains energy directly from breakdown of ATP
- transports both sodium and potassium
Secondary:
- indirect use of energy store
- able to go against concentration gradient without breaking down ATP
- movement of 2 or 3 substances is linked
What causes/maintains resting membrane potential?
- Plasma membrane as selective controllable barrier (donnan effect)
- Sodium potassium pump (3 na out and 2 k in)
How is an action potential generated?
Membrane potential set by balance of ion gradients and permeability
Depolarisation (caused by a trigger) upsets the balance
If depolarisation less than 20mV, membrane potential will fall again
If depolarisation is greater than 20mV, threshold level is reached and action potential is generated
Describe the structure of proteins
Primary: sequence of amino acids joined by peptide bonds
Secondary: structures are not dependent on the side chain as the H bonds form between carbonyl group of the peptide bond and H atom of another
- alpha helix: coiling is always clockwise and hydrophobicity determined by side chains
- beta sheets: occurs when H bonds form between peptide chains that lie alongside each other
- u turn: consists of 3-4 residues
Tertiary: disulphides, hydrogen, ionic and hydrophobic bonds
Quaternary: acetylation, glycosylation and phosphorylation
Functions of membrane proteins
Junctions Enzymes Transport Recognition Anchorage Transduction
Regulation of glycolysis
- Hexokinase (catalyses glucose to glucose-6-P)
- Phosphofructokinase (catalyses fructose-6-P to fructose-1,6-bisphosphate)
- Pyruvate kinase (catalyses phosphopenolpyruvate to pyruvate)
These are three irreversible steps of glycolysis
Citric acid cycle definition and process
Common pathway by which all fuel molecules are broken down to co2 and h2o
- A 2 carbon molecule (acetyl coa) is condensed with a 4 carbon molecule (oxaloacetate) to form a 6 carbon molecule (citrate)
- Citrate is broken down in stages, finally resulting in formation of a new molecule of the original 4 carbon compound
- Additional products: 3 NADH, 1 FADH2, 2 co2, 1 GTP
What are the 4 regulatory protein families that are termed receptors?
- Enzymes
- Carrier molecules
- Ion channels
- Neurotransmitter, hormone or local hormone receptor
Examples and mechanism of action of drug receptor interactions: Ligand-gated ion channels
Changes in membrane potential or ionic concentration within cell —> intracellular effects
E.g cholinergic nicotinic receptors
Local anaesthetics
Examples and mechanism of action of drug receptor interactions: G-protein coupled receptors
Binding site on Extracellular site and then info transferred through the domains and reaches inside —> allowing cascading. Protein phosphorylation and intracellular effects
E.g alpha and beta adrenoreceptors
Examples and mechanism of action of drug receptor interactions: enzyme linked receptors
Protein and receptor phosphorylation –> Intracellular effects
E.g insulin receptors
Examples and mechanism of action of drug receptor interactions: intracellular receptors
Protein phosphorylation and altered gene expression
E.g. steroid receptors
What is the equilibrium dissociation constant?
The concentration of drug required to occupy 50% of the receptors at equilibrium.
It is a measure of affinity if any one drug for a receptor
Drug affinity and the pd2 value
The lower the pd2 value, the greater the affinity that drug has for the receptor
Antagonist classifications
Flowchart: 1
2 principles for slowness of implementing the Biopsychosocial approach to primary care
- Lack of incentives
- payment schemes
- clinical guidelines - Work load and competency issues
Co-morbidities of obesity
Diabetes Hypertension CHD Respiratory problems Sleep apnoea Non alcoholic fatty liver disease Osteoarthritis Cancer
Different methods of transport across cell membranes
UNIPORT
- simple diffusion
- facilitated diffusion
- active transport (primary or secondary)
COTRASPORT
- symport (both molecules are being moved in the same direction)
- antiport (both molecules being moved in different directions)
Define passive transport
Rate of diffusion into the cell = permeability coefficient x conc gradient across membrane
Define partition coefficient
Partition coefficient gives a measure of how well a substance dissolves in lipid or aqueous phase
What is the respiratory chain?
Movement of electrons down the respiratory chain generates a H+ ion (pH) gradient across the inner mitochondrial membrane.
This gradient is used to drive ATP synthesis by way of ATP synthase
Define pharmacokinetics and pharmacodynamics
Pharmacodynamics: what the drug does to the body
Pharmacokinetics: what the body does to the drug
What is metabolic syndrome?
sometimes under the name insulin resistance:
- obesity
- hypertension
- dyslipidaemia
- glucose intolerance
- raised inflammatory markers
- abnormal blood clotting
Stages of atherosclerosis
- lesion initiation
- fatty streak
- fibrous plaque
- thrombosis
