Case 1.1 Flashcards

Question

What is the function of plasma?

Answer 1

Transport gases, nutrients, cells, hormones, antibodies, and metabolites around the body

Answer 2

Generally: destroy infecting organisms and remove dead and damaged tissue. Basophils = inflammation, histamine and heparin production, phagocytosis Eosinophils = parasites, allergy Neutrophils = remove damaged tissue and kill small organisms Macrophages (monocytes) = destroy invading organisms - phagocytosis NK cells = engulf foreign cells T cells = specific immune response B cells = antibody synthesis

Answer 3

The fraction of the blood composed of red blood cells: Haematocrit (HCT) Erythrocyte sedimentation rate (ESR): The rate at which the red blood cells settle to the bottom of the test tube. Total amount of haemoglobin in the blood(Hb) Mean cell haemoglobin (MCH-from Hb and RBC) Mean cell volume (MCV-average volume of a red blood cell) Mean cell haemoglobin concentration (MCHC-average concentration of Hb in a given volume of packed red blood cells)

Answer 4

High = dehydration Low = anaemia (low Hb= anaemia/blood loss)

Answer 5

Leukopaenia (low WBC) = bone marrow failure | Leukocytosis (high WBC) = infection and inflammation/leukaemia

Answer 6

DNA, histones, chromosomes, gametes, alleles (dominant and recessive), punnet squares (inheritance and variation).

Answer 7

A very long polymer of nucleotides (deoxyribose, phosphate group and nitrogen base = AGCT) with phosphodiester bonds. Basic shape = twisted ladder, double helix, where the rungs are nucleotide pair bonds (nitrogenous bases). Pyrimidines = thymine and cytosine, one ring of carbon and nitrogen atoms. Purines = adenine and guanine, two rings of carbon and nitrogen atoms. AT, CG = Chargraff's rule. Attracted by hyrdogen bonds. Genes are organised into chromosomes, which are stored on histones.

Answer 8

``` Single strand, sugar-phosphate backbone = ribose. Thymine -> Uracil substitution. mRNA = messenger tRNA = transfer (for protein synthesis) rRNA = part of ribosome miRNA = post-transcriptional regulation. ```

Answer 9

Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product (often proteins). This involves transcription, where the DNA is copied to RNA. In the nucleus, RNA polymerase (an enzyme) adds nucleotides one by one to form a strand which is complementary to the DNA template strand, creating a copy of the coding strand (except U not T). This process is initiated by a special DNA sequence called the promoter and a set of DNA-binding proteins—transcription factors. Addition of new nucleotides begins at the 3' end of the template or 'anti-sense' strand.

Answer 10

Central Dogma: DNA → RNA → Protein Every 3 nucleotide pairs are a codon, each codon is one amino acid. mRNA is converted to tRNA, which has unique anticodons for each amino acid. Protein +rRNA = ribosomes.

Answer 11

The parts of the mRNA which code for proteins are called exons (cut out = introns). Whether they are exons or introns is signalled by certain sequences. At the end of processing, RNA is modified by capping (G-cap attached to 5' end), splicing (removal of introns), and tailing (As added to 3' end). This protects RNA from degradation and provides recognition sequences.

Answer 12

To respond to immediate environment, central commands, local commands etc., coordinate cellular responses, integrate signals from multiple sources and sometimes to initiate cell death.

Answer 13

1. Reception A chemical message binds to a protein on the cell surface 2. Transduction The binding of the signal molecule alters the receptor This starts a cascade of reactions 3. Response The transduction pathway triggers a response The responses can vary from turning on a gene, activating an enzyme, rearranging the cytoskeleton

Answer 14

Chemical (neurotransmitters/hormones) Physical/mechanical Junctions

Answer 15

G Protein Coupled Receptors

Answer 16

G Protein Coupled Receptors G = guanine nucleotide-binding protein

Answer 17

A single long polypeptide chain folded into a globular shape with portions inside and outside the cell. Interacts with G proteins in the plasma membrane (alpha, beta and gamma subunits).

Answer 18

Binding of a signal on the outside changes the shape of the receptor and activates the G protein to activate local enzymes - adenylyl cyclase and phospholipase C.

Answer 19

Gs: activation of adenylate cyclase and production of cAMP Gi: inhibition of adenylate cyclase and decreased production of cAMP Gq: activation of PLC to produce IP3 and DAG (calcium signalling) s/i/q is the name of the alpha subunit (something called Gαs, Gαi, Gαq

Answer 20

The channel opens in response to a chemical, allowing ions to move through and change the electrical properties of the cell. Important in nerve and muscle cells - ACh receptor, GABA receptor, 5HT3.

Answer 21

Consists of an extracellular ligand binding domain, a single transmembrane helix, a cytoplasmic region containing the protein tyrosine kinase activity. Activation causes them to come together and autophosphorylate, stimulating signal transduction pathways. Examples include insulin and growth factor receptors.

Answer 22

The addition of a phosphate group to a protein or other organic molecule = turns many protein enzymes on and off. Can be catalysed by kinases.

Answer 23

For signals that can cross the cell membrane, e.g. oestrogen, thyroid hormone. Alter gene transcription and therefore protein levels directly.

Answer 24

1. Receptor activation leads to intracellular signalling cascades and second messenger systems 2. These lead to changes in cell function 3. Signals are turned off eg. Chemical signals are enzymatically degraded G proteins become inactivated by GTPases 4. Cells return to previous state (unless more signal is around)

Answer 25

Allow small molecules and ions to pass Narrow pore (2-4nm) spanned by pore forming proteins called connexins Provide rapid metabolic and electrical coupling E.g. cardiac tissue (coordinated action)

Answer 26

Gasotransmitters include oxygen, carbon dioxide, NITRIC OXIDE [e.g. GTN in angina to dilate coronary arteries], carbon monoxide, etc. Enzymatically generated Cellular and molecular targets Permeable to membranes (no receptor required)

Answer 27

A cell sending a signal to itself, e.g. IL-1 in response to monocytes.

Answer 28

Hormonal, long distance signals, e.g. insulin.

Answer 29

Deriving from a nerve, e.g. noradrenaline.

Answer 30

Local cell signalling, e.g. thromboxane in clotting.

Answer 31

Cell signalling which requires contact through communicating cells, e.g. leukocytes and adhesion molecules on endothelial cells.

Answer 32

All of a living organism's chemical reactions, which are integrated and form pathways (sequences of reactions leading to a particular end point).

Answer 33

Chemical reactions which lead to energy storage and biosynthesis.

Answer 34

Metabolic reactions that lead to the release of energy and degradation of compounds.

Answer 35

ESSENTIAL COMPOUNDS (specific range is key) Vitamins Minerals (electrolytes, macro etc.) Essential amino acids Essential fatty acids (Omega 3 and 6, needed to make eicosanoids [C20]) ``` ENERGY-YIELDING COMPOUNDS Carbohydrates Fats Proteins - All converted to acetyl CoA, which is converted into ATP and CO2 by oxidative phosphorylation. ```

Answer 36

A protein catalyst which typically makes or breaks a covalent bond - can accelerate a reaction. Not typically consumed in the reaction. Can be a protein or RNA. They stabilise the transition state of a chemical reaction, lowering the activation energy. Can cause astonishing rate enhancements.

Answer 37

``` Oxidoreductases: catalyze oxidation-reduction reactions Cytochrome c (energy production) ``` Transferases: catalyze group transfer Kinases (major drug target) Hydrolayses: catalyze hydrolysis reactions Proteases (normal digestion of proteins) ``` Lyases: catalyze addition of groups to double bonds or creation of double bond by group removal Adenylate cyclase (produces cAMP) ``` ``` Isomerases: catalyze transfer of groups within a molecule DNA topoisomerase (common drug target for Antibiotics, Cancer) ``` ``` Ligases: catalyze condensation reactions DNA ligase (DNA repair) ```

Answer 38

Irreversible inhibition (e.g. nerve gas) Reversible inhibition (competitive/non-competitive) Negative feedback inhibition etc. Also regulated by the environment - pathogens, temperature, pH etc.

Answer 39

Combined incidence of 1;5000, >200 errors known. Most autosomal recessive or X-l;inked inherited, usually a single gene defect in a key pathway. Signs/symptoms due to toxic accumulation of substrate behind the block or deficiency of product after the block.

Answer 40

Empirical Milestones of development e.g. Griffiths, Bayley scales of development Psychoanalytic e.g. Freud, Erikson Cognitive e.g. Piaget, Vygotsky (social) Also behavioural and moral.

Answer 41

Erikson: 0-18 months = trust vs. mistrust = oral-sensory, development of attachment 18m-3y = autonomy vs. shame = motor development, will, illness as punishment 3-5y = initiative vs. guilt = play, social roles, magical ideas of illness 6-12y = industry vs. inferiority = social development, 'germ' concept of illness 12-18y = identity vs. role confusion, struggle for autonomy, peer approval, experimentation. 18-35y = intimacy and solidarity vs. isolation, permanent partnerships, adult roles. 35-55y = generativity vs. stagnation, cultural value transmission, diseases of affluence 55-death = integrity vs. despair, dealing with loss, impaired perception, mobility etc.

Answer 42

Sensory & motor (gross motor/fine motor and vision) Communicative & linguistic (speech, language and hearing) Social (emotional and behavioural) Adaptive behaviour Motor reflexes: - rooting disappears @ 3 weeks - stepping @ 2m - Moro @ 6m - Babinski @ 8-12m - eye blink, sucking and gag remain. ``` Head to toe acquisition: Head control (some by 6 weeks) - by 4 months in sitting Hand control - grasping from birth, holding toy by 3m, reaching @ 4m, passing @6m, casting @ 7-9m ``` Rolling 4-7m, sitting 6m, crawling 6m, pull to standing 9-12m, walking 12-18m. Poor distance vision at birth, turning head to sound at birth.

Answer 43

PKU = a genetic disorder where the body’s enzyme, phenylalanine hydroxylase (PAH), is missing or malfunctioning so that it cannot properly break down the amino acid, phenylalanine (phe). Symptoms: cognitive disability, seizures, microcephaly, skin rashes, growth problems, hyperactivity, musty body odour, fair skin, hair and eyes. Social development: play and peer relationships impacted (autism/hyperactivity), family, cognitive development.

Answer 44

The formation of a strong, reciprocal emotional bond between an infant and a primary caregiver. Indicated by proximity seeking, separation distress and pleasure when reunited, and general orientation towards specific individual. 0-2 months = pre-attachment 3-7 months = indiscriminate attachment (familiar people) First discriminate attachment by 8 months, stranger anxiety by 9 months.

Answer 45

Bayley (1-42 months).

Answer 46

ATG/AUG - methiamine. | Stop = TAA, TAG or TGA.

Answer 47

Protein primary structure: sequence of amino acids. Protein secondary structure: organisation of peptide chains into structures. – alpha helices etc. Protein tertiary structure: 3D macromolecular structure. Protein quaternary structure: assembly of multiple folded protein molecules in a multi-subunit complex.

Answer 48

Central carbon Basic amino group (H2N) Hydrogen atom Acidic carboxyl group (properties depend on this) Side chain (R, contributes charge, polarity and hydrophobicity, plus 2ndary and tertiary structure - hydrogen bonds)

Answer 49

A change in one base can alter which amino acid is produced, which can have a major effect depending on how different the amino acids are (e.g. charge). Frame shifts have the most severe impact, as they change all subsequent acids. E.g. haemophilia - severity depends on mutation.

Answer 50

the covalent and generally enzymatic modification of proteins during or after protein biosynthesis. Proteins are synthesized by ribosomes translating mRNA into polypeptide chains, which may then undergo PTM to form the mature protein product.

Answer 51

Where a ligand binding to a membrane receptor triggers an alteration in enzymatic activities driven by protein post-translational modifications (PTMs). E.g. protein phosphorylation, AMP+protein kinase -> ADP Phosphatase reverses it. Transfer of phosphate may involve kinases activating each other = kinase cascade. MAPKKK.

Answer 52

Signals altering DNA methylation and histone PTMs. Inactive DNA is usually bound to the histone and extensively methylated, but acetyl transferase adds an acetyl group and changes polarity, breaking the bond between DNA and histone. This means it can now be found by transcription factors.

Answer 53

A chemical which affects the functioning of the body. | E.g. medicines, substances of abuse. Can have pharmacological/toxicological action.

Answer 54

There is no uniform system of classification. The main ones are therapeutic use, mode of action, and chemical structure.

Answer 55

1. Direct physiochemical effect e. g. bulk-forming laxatives, antacids, osmotic diuretics, plasma expanders. 2. Effect on transport systems Ion channels, e.g. local anaesthetics, calcium channel blockers, sulphonylureas Or carriers, e.g. loop diuretics 3. Enzymes Competitively inhibit. E.g. antibiotics, trimethoprim and sulphonamides 4. Interaction with receptors (mostly proteins) GPCR/ion channel/enzyme/intra-cellular Four main kinds of regulatory protein are commonly involved as primary drug targets, namely: • receptors • enzymes • carrier molecules (transporters) • ion channels.

Answer 56

1. Ion channels (fast neurotransmitters) = in membrane, direct coupling, GABA. 2. GPCRs = membrane, channel or enzyme effector, changes levels of G proteins (coupling), which affect second messengers and excitability. ACh/adrenoceptors. 3. Kinase-linked receptors = membrane, protein kinases (effector) - protein phosphorylation -> gene transcription -> protein synthesis, direct, e.g. insulin, growth factors, cytokines. 4. Nuclear receptors = intracellular, coupling via DNA, e.g. steroid receptors.

Answer 57

Gs increases cAMP, beta2 A2 and IP receptors, adrenaline, adenosine, prostacyclin. Gi decreases cAMP, alpha 2 receptors, Adrenaline/noradrenaline. Gq increases IP3 and Rho-kinase, alpha1, ETA, AT1 and V1 receptors. Adrenaline, angiotensin, vasopressin.

Answer 58

Depends on structure and metabolism of microorganism and host and groups of bacteria (gram positive or negative).

Answer 59

+ can treat most infections, even if you don't know what it is - increased risk of resistance and side effects compared to a narrow spectrum antibiotic.

Answer 60

1. Interfere with bacterial cell wall (peptidoglycan synthesis = cell lysis) 2. Interfere with protein synthesis 3. Interfere with replication of genetic material (DNA and RNA)

Answer 61

Beta-lactams and glycopeptides (e.g. vancomycin) | - resistance. Glycopeptides only active against gram positive.

Answer 62

Penicillins eg benzylpenicillin, flucloxacilin Cephalosporins eg cephalexin, cefuroxime Carbapenems eg imipenem, meropenem Monobactams eg aztreonam Cephamycins eg cefoxitin

Answer 63

Tetracyclines, Aminoglycosides, Chloramphenicol, Macrolides Others: streptogramins, lincosamides (clindamycin), oxalazidonones (linezolid), ketolides, fusidic acid

Answer 64

Bactericidal for G+ but especially G-, inactive against anaerobes.

Case 1.1 Flashcards

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