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)