Year 1 Definitions Flashcards
Absorbance (Au)
The amount of light that is absorbed by the solution
Active Site
A small indentation on the surface of the enzyme, made from 3 – 12 R-groups. The rest of the polypeptide chain is important in holding those R-groups in the correct orientation to form the active site
Active Transport
The active movement of molecules against their concentration gradient
Agglutination (blood types)
The clumping of erythrocytes occurs if an antigen is mixed with its corresponding antibody
Anticodon
Consists of 3 exposed RNA-nucleotides
only found at the base of tRNA molecules
Each anticodon is specific for one amino acid
each tRNA will have a specific anticodon which determines the amino acid it carries
Apoenzyme
An inactive enzyme which needs the presence of a co-factor to activate it
ATP
A phosphorylated nucleotide which is a short-term energy store
Atheroma
A build-up of white blood cells that have taken up low-density-lipoproteins and become deposited in the lining of the artery walls
Deposits cholesterol, dead fibres and muscle cells and restricts blood flow
Causes myocardial infarction
Biosensor
Analytical device used to detect presence of a chemical molecule (the analyte) by combining the chemical with a biological component
Capillaries
Site of exchange between plasma and cells (so glucose and O2 is delivered to cells)
Cardiac Arrest
When the heart no longer functions usefully as a pump
Cardiac Output
The volume of blood pumped out of the left ventricle each minute
Chromosome
Lengths of DNA that are wrapped around a protective layer of protein called the histone coat.
A linear structure consisting of 1 molecule of DNA
Usually found in pairs in somatic cells
Carry 100s to 1000s of genes each
Chromosome Mutation
A change to the structure (whole or part) of a chromosome (i.e. deletions, insertions, translocations)
Closed Circulatory System
Blood always moves within blood vessels, which allows pressure to be maintained
Codon
A triplet of DNA nucleotide bases that code for a specific amino acid
Cofactor
Additional non-protein component that is needed by the enzyme to enable it to function
Condensation Reaction
The joining of 2 monomers by the removal of H2O to form a new covalent bond
Degenerate Code
There are more codon possibilities than amino acid
Deletion Mutation
Deletion of one or more DNA bases, causes a frameshift, resulting in loss of function of protein coded for by the gene
Diastolic Pressure
The pressure during diastole = the pressure in the arteries when the heart rests between beats
Disulfide Bonds
Formed between the sulphur atom of R-groups of 2 cysteine amino acids
Double Circulatory System
Blood passes through the heart twice per complete circuit around the body (pulmonary circuit and systemic circuit)
Enzyme Inhibitor
A small molecule that interacts with an enzyme to reduce the rate of reaction
Eutrophication
The enrichment of a water body with nutrients, usually with an excess amount of nutrients, including growth of plants and algae and resulting in oxygen depletion of the water body
Exon
Sections of DNA that code for a specific sequence of amino acids in a polypeptide chain
Facilitated Diffusion
The passive movement of molecules down the concentration gradient through specialised proteins until an equilibrium is reached across a partially permeable membrane
Genome
The total collection of all the genes within an organism or cell
Histone
A protein that provides structural support for a chromosome
Holoenzyme
A complex of an enzyme with its cofactor. The complex is active so the enzyme will function
Hydrogen Bonds
Weak interactions between atoms with slight positive and slight negative charges (i.e. between dipoles)
Hydrolysis Reaction
The splitting of a polymer to remove a monomer by the addition of H2O to break an existing covalent bond
Hydrophobic Interactions
Water is repelled and excluded from hydrophobic, non-polar R-groups
Hypertension
Persistently high blood pressure (clinic BP of 140/90 mmHg / home BP of 135/85 mmHg)
Hypertonic Solution
The solution has a higher number of solute molecules, and a low water potential
Hypotension
Persistently low blood pressure
Hypotonic Solution
The solution has a lower number of solute molecules, and a high water potential
Hypovolemic Shock
Shock caused by excessive blood loss and fluid loss, where 1/5 or more of blood volume is lost, resulting in organ failure
Insertion Mutation
Addition of one or more DNA bases, causes a frameshift, resulting in loss of function of protein coded for by the gene
Intron
Genetic rubbish (i.e. sections of DNA that do not code for a sequence of amino acids within a polypeptide chain)
Ionic Bonds
Formed between R groups which have carboxyl groups (COO-) and amino groups (NH+)
Isoenzymes
Enzymes that differ in amino acid sequence but catalyse the same chemical reaction
Isotonic Solution
Two solutions either side of the partially permeable membrane have the same water potential
Lymph Fluid
Similar to tissue fluid, but more leucocytes, important in immune response, and lymph nodes are the site for filtration of pathogens and foreign bodies
Magnification
The degree of enlargement of an image to reveal further detail
Mutation
A change in the arrangement of bases in a gene or in chromosome structure
Mutation Rate
A measure of the rate at which various types of mutations occur over time
Myocardial Infarction
When the blood supply to cardiac muscle is totally or partially cut off, preventing aerobic respiration in muscle cells
Myogenic
No nerve stimulation required to make the cardiac muscle contract
Non-Reducing Sugar
Sugars without the ability to donate an electron to another molecules (e.g.: sucrose)
Osmosis
The passive movement of water molecules from an area of high water potential to an area of low water potential down a water potential gradient through a partially permeable membrane
Peptide Bonds
Formed by condensation reaction between NH group of one amino acid and the COOH group of the adjacent amino acid
Point Mutation
A change to the structure of a gene due to a change in the DNA-nucleotide base sequence
Primary Structure of a Protein
Sequence of amino acids within the polypeptide chain (amino acids joined by series of condensation reactions resulting in peptide bonds)
Productivity
The amount of energy available at one trophic level for a defined area over a defined period of time
Prostaglandins
A group of chemicals, synthesised from a fatty acid called arachidonate
Pulse
The expansion of the artery wall during ventricular systole, and the elastic recoil during diastole. Pulse can be taken at radial, temporal and carotid artery or in groin (femoral artery)
Quaternary Structure of a Protein
Presence of 2 or more polypeptide chains joined together, OR presence of 1 polypeptide chain and at least 1 non-protein prosthetic group
Q10 Rule
For every 1°C rise in temperature, the rate of an enzyme controlled reaction will double up until its optimum temperature
(Beyond optimum temperature, rate of reaction will decrease sharply to 0 as the enzyme is denatured)
Repeatable
If someone was to carry out the test again using the same method and got the same result, then data is repeatable
Reproducible
If a measurement was taken using a different method and got the same result, the result is referred to as reproducible
Resolution
The ability to distinguish between two different points and to see detail
Reversibility
Some enzymes catalyse reactions in either direction (e.g. Carbonic anhydrase) and the direction of reaction depends on environmental conditions
Secondary Productivity
The rate at which animals convert chemical energy in the plants they consume into their own biomass
Secondary Structure of a Protein
Folding of the polypeptide chain to form either alpha helices or beta pleated sheets
Semi-Conservative Replication
Each polynucleotide strand of DNA acts as template for the synthesis of a complementary strand. New DNA molecule has one original polynucleotide strand and one new polynucleotide strand
Simple Diffusion
The passive movement of molecules down the concentration gradient until an equilibrium is reached across a partially permeable membrane
Specificity
Enzymes only work on specific substrates, as the shape of the substrate must be complementary to the shape of the active site
Streptokinase
Enzyme secreted as toxin by many different species of Streptococcus bacteria
Stroke Volume
The volume of blood pumped out of the left ventricle during the cardiac cycle (60-80cm3)
Substitution Mutation
May have no effect (silent) or may lead to loss of function of the protein coded for by the gene (nonsense or missense)
Sustainable Fishing
Removing a controlled number of fish from the natural population, allowing the remainder to reproduce and replenish. Means there is no significant reduction in adult population
Systolic Pressure
The pressure in the arteries as blood is forced out of the left ventricle during systole
Tertiary Structure of a Protein
Further folding of the polypeptide chain to produce a complex 3-dimensional shape. Results in a globular arrangement (i.e. a G-protein)
Tissue Fluid
Fluid that surrounds the cells of the body, supplies cells with nutrients and removes waste products
Transmission
The amount of light that passes through the solution
Transpiration Stream
The movement of water from the roots to the leaves via mass flow and transpiration
Turnover Rate
The maximum number of chemical conversions of substrate molecules per second that a single catalytic site carries out at a given concentration of enzyme
Ventricular Fibrillation
Rapid, uncontrolled contraction of the muscles in the ventricles, resulting in no effective movement of the blood
Transpiration
The loss of water vapour by diffusion from the underside of the leaf (the aerial part of the plant) via the open stomata
Apoplast Pathway
Water moves through cellulose cell walls, along cellulose fibre in walls, and through space in fibres. Route offers little resistance so most water travels via this route
Symplast Pathway
Water travels through CSM to the protoplasm of cell via osmosis from root hair cells through cells of root cortex down a water potential gradient. Water also moves through plasmodesmata from cytoplasm to cytoplasm
Vacuolar Pathway
Water moves vacuole to vacuole via neighbouring cells, crossing symplast and apoplast pathways
Translocation
The movement of nutrients around the plant from source to sink
Tissue
A group of one or more cell types that are specialised and working together for a particular function
Organ
A group of one or more tissue types that are specialised to carry out specific functions
Organ System
A collection of organs with a particular function
Tidal Volume
The volume of air that moves in and out of the lungs during a normal breath
Vital Capacity
The maximum amount of air that can be forcibly expelled from the lungs following breathing as deeply as possible (approx.. 2-5 dm3)
Residual Volume
The volume of air remaining in the lungs after a maximal expiratory effort
Dead Space
The volume of non-exchange surfaces in the breathing system
Pulmonary Ventilation
The amount of air exchanged with the environment per minute
FEV(1)
Forced Expiratory Volume, as in the volume of air that can be breathed out in the first second of forced exhalation
PEFR
Peak Expiratory Flow Rate, as in the maximum rate of forcing air out through the mouth
Apoptosis
Programmed cell death, initiated by p53 (a tumour suppressor protein), important for growth, development and cell proliferation
Stem Cell
An undifferentiated cell that is capable of differentiating into a range of cell types
Differentiation
The development of unspecialised cells to form specialised cells
Totipotent Stem Cell
A stem cell that has the ability to form a whole organism and extra-embryonic membranes
Pluripotent Stem Cell
A stem cell that is found in embryos as the 50-100 cell stage
Multipotent Cell
A stem cell that has the ability to differentiate into a limited range of different cell types
CVS
Chorionic Villus Sampling
= the removal and testing of small sample of placental and chorionic villus cells to test for genetic abnormalities using a transcervical / transabdominal needle
Amniocentesis
The removal and testing of approx. 20cm3 amniotic fluid to test for genetic abnormalities
Karyotyping
The photographing of paired, sized chromosomes to identify chromosomal abnormalities from malfunctions or disease
Classification
The grouping of organisms based on the similarity of features
Taxonomy
The science of studying classification and the differences between species
Phylogeny
The study of evolutionary relationships between organisms
Species
A group of organisms which can interbreed successfully to produce fertile offspring
Biological Species Concept
A group of organisms with similar morphological, physiological, biochemical and ecological features that can interbreed to produce fertile offspring
Phylogenetic Species Concept
A group of organisms that share a common ancestor and have the same evolutionary history
Adaptation
The possession of a feature that has increased the chances of survival of an individual to enable it to reach reproductive age and reproduce successfully
‘Vocal Grooming’ Theory of Language Evolution
Vocal grooming maintained social bonds in groups that became larger. Began as simple sounds, then evolved into more complex language
‘Mother Tongue’ Theory of Language Evolution
Words and basic language evolved for communication between mother and offspring
Selection Pressures
Environmental factors that drive evolution in a particular direction
Speciation
The evolution of a new species
Allopatric Speciation
When a geographical barrier separates two populations, causing them to experience different selection pressures so different traits evolve. Eventually they are different enough that they can no longer interbreed
Sympatric Speciation
Reproductive isolation, usually arising from allopatric speciation (e.g.: cannot attract a mate, incompatible genitalia, different mating or flowering seasons)
Health
Being free from disease, having physical, social and mental wellbeing, having good nutrition and being suitably housed
Disease
A malfunction of the body and/or mind that adversely affects the health of an individual and leads to impairment of normal functioning
Communicable Disease
A disease or infection capable of being transmitted or communicated to another living organism
Virulence
A measure of the ability of a pathogen to cause disease
Latent TB
TB that causes no symptoms, so treatment is not required by the disease must be monitored
Retrovirus
A virus that contains RNA and reverse transcriptase
Incidence Rate
The number of new cases of a disease in a population each year
Endemic
An infectious disease being constantly present in a population
Epidemic
A sudden increase in the incidence of an infectious disease in a confined area
Pandemic
An increase in the incidence of an infectious disease in several countries
Morbidity
The number of people who have a certain disease
Mortality
The number of people who have died from a certain disease within a population
Notifiable Disease
A disease that, upon diagnosis by a doctor, must be reported to the local authorities and Public Health England
Immune Response
A response to the presence of a foreign antigen involving the activation of lymphocytes and the production of antibodies
Primary Defences
Mechanisms that have evolved to prevent the entry of pathogenic organisms
Antibodies
Soluble glycoproteins, produced by B plasma cells, that bind to complementary antigens on the surface of the pathogen
Neutralisation
Antibodies combine with viruses or bacterial toxins to prevent them entering or damaging cells
Agglutination (antibodies)
Antibodies immobilise pathogens by clumping them together to stop them entering the cell and making them easier to be phagocytosed
Immobilisation
Antibodies stop movement of bacteria by attaching to flagella
Lysis-Antibodies
Antibodies that bind to foreign bodies and attract complement proteins which ‘punch’ pores in the CSM
Opsonisation
The constant region of antibodies attaches to receptors on CSM on phagocyte. The variable region attaches to antigens on the pathogen so the pathogen can be engulfed
Hypersensitivity
An undesirable reaction produced by the immune system
Sensitisation
Initial contact with the allergen triggers primary immune response. Plasma cells produce Immunoglobulin antibodies, which bind to receptors on mast cells
Active Immunity
Activation of B and T lymphocytes in response to presence of pathogenic antigens, resulting in production of antibodies and memory cells
Passive Immunity
No activation of lymphocytes and no memory cells produced, presence of antibodies only
Natural Immunity
e.g.: from mother to foetus across placenta / breast milk
Artificial Immunity
Injection of antibodies from another source
Vaccination
Deliberate exposure of an individual to antigens from a foreign source in order to provoke an immune response and provide immunity (artificial active immunity)
Live-Attenuated Vaccine
Modified strains of bacteria / viruses that can multiply but are NOT pathogenic.
Strongest response and long-lasting immunity
BUT cannot be given to those with compromised immune systems
Killed-Inactivated Vaccine
Bacteria / virus is killed with chemical treatment but antigens remain intact, provoking an immune response.
More stable than LA vaccine, doesn’t need refrigeration
BUT weaker response so boosters needed
Toxoid Vaccine
Toxoids extracted and treated with formaldehyde to prevent symptoms = triggers immune response and production of antitoxins.
Safe when toxins cause virulence
BUT doesn’t give strong immune response
Subunit Vaccine
Only specific antigens extracted and used.
Can construct vaccines for several strains
Artificial Antigen Recombinant Vector
Genes coding for the antigens of the pathogen are transferred through genetic engineering to harmless microorganisms.
Provides immunity to agents that can’t easily be attenuated without destroying antigen activity
Ring Vaccination
A vaccination ring around the geographical centre of an epidemic to prevent its spread
Protein Energy Malnutrition
Insufficient protein consumption, so cannot make antibodies or memory cells due to insufficient amino acids
Antibiotic
A chemical that kills or slows down the growth of bacteria
Bactericidal Antibiotics
Kill bacteria by disrupting cell wall or by disrupting protein synthesis
Bacteriostatic Antibiotics
Prevent growth or reproduction of bacteria (e.g.: tetracycline prevents tRNA binding to ribosomes so protein synthesis cannot take place)
Sulphonamides
Competitive inhibitors of bacteria membranes. Inhibit enzymes that assist in synthesis of folic acid so DNA (purines) can’t be synthesised
Erythromycin
Blocks sites on ribosomes so prevents protein synthesis, so polypeptide chain cannot be elongated (used in preventing communicable diseases)
Broad Spectrum Antibiotics
Work well against a wide range of bacteria
Narrow Spectrum Antibiotics
Only effective against certain types of infection
Non-Communicable Disease
A disease which is non-infectious and non-transmissible among people
Risk Factor
A variable associated with an increased chance of developing a disease or infection
Tumour
A lump or growth of abnormal cells that divide uncontrollably
Cancer
A disease usually caused by a mutation that causes uncontrolled cell division and the subsequent formation of a tumour
Metastasis
The process in which cancer cells break from the primary tumour and spread to initiate a secondary tumour formation at a different location
Benign Tumour
Slow growing, not normally life-threatening, do not normally grow back
Malignant Tumour
Fast growing, metastatic, can be life-threatening
Mutagen
A physical, biological or chemical agent that mutates the DNA of an organism and increases the frequency of mutations above the natural background level
Screening
Testing people who are known to be at risk of a certain condition before symptoms develop
Chemotherapy
The use of chemicals that are toxic to dividing or cancerous cells
Radiotherapy
Ionising radiation is accurately targeted to destroy actively growing cells
Immunotherapy
Monoclonal antibodies can be tagged with an enzyme that converts an inactive form of a cytotoxic drug into an active form that targets cancerous cells
Hormone Therapy (cancer treatment)
Oestrogen stimulates transcription of genetic material if cells have ER+ factors (oestrogen receptors), aromatase inhibitors can be given to post-menopausal, early-stage breast cancer sufferers and LH blockers prevent oestrogen synthesis
Lumpectomy
Surgical method to treat breast cancer, includes removing the tumour and barrier tissue
Mastectomy
Surgical method to treat breast cancer, includes removing the whole breast and lymph nodes
Colectomy
Surgical method to treat colon cancer, includes removing tumorous section of colon and re-joining colon by anastomosis
Pollutant
A substance released into the environment that can harm organisms or the environment itself
Asthma
The inflammation and subsequent narrowing of the bronchi. Its stimulants are fur, exercise, cold air, tobacco and genetic factors
COPD
Chronic Obstructory Pulmonary Disorder. A combination of emphysema and bronchitis
Placebo
A substance containing no active ingredient which has no effect on its recipient, yet its appearance, smell and taste is identical to the real drug. Used to compare the effectiveness of the tested drug
NICE
National Institute for Health and Care Excellence. Assess clinical-effectiveness and cost-effectiveness of health technology. Evaluates whether effectiveness justifies use. Offers guidance on other appropriate treatment or procedures
