Glossary Flashcards
Acid
A chemical that gives off hydrogen ions in water and forms salts by combining with certain metals
Acidosis
A condition where there is too. much acid in the body fluids. Blood pH less that 7.35
Active transport
The movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy
alkali (or base)
A chemical that can dissolve in water, combine with acids to form salts and make acids less acidic
amino acid
molecules that combine to form proteins
anion
negatively charged ion, eg. one that would be attracted to the anode in electrolysis
aqueous
containing water, relating to or resembling water
atom
smallest unit of matter that retains all chemical properties of an element
buffer
A solution that can resist pH change upon the addition of an acidic or basic component
Cation
Positively charged ion, one that would be attracted to the cathode in electolysis
Compound
A thing composed of two or more seperate elements (a mixture)
condensation
The conversion of vapour (or gas) to a liquid
disaccharide
Any substance that is composed of two molecules of simple sugars
diffusion
The intermingling of substances by the natural movement of their particles
electrolyte
Substances that have a natural positive or negative electrical charge when dissolved in water
electron
A negatively charged subatomic particle that can be either bound to an atom of free (not bound)
element
a substance that can be broken down by non-nuclear reactions
endocytosis
A process by which cells absorb external material by engulfing it with the cell membrane
endothermic
characterised by or formed with absorption of heat
enzyme
make actions happen more quickly
evaporation
process of turning from liquid into vapour
exocytosis
bulk transport of substances out of a cell, lipids/proteins are secreted by exocytosis, requires cellular energy
exothermic
a chemical reaction that releases heat/energy
facilitated diffusion
the movement of particles across cell membrane through carrier proteins (passive)
half-life
The time taken for the number of radioactive particles of an isotope to decrease to half its original number, measure rate of decay
hydrocarbon
An organic molecule containing only hydrogen and carbon atoms
hydrolysis
the chemical breakdown of a molecule or compound by water
hydrophilic
attracts water, soluble in water eg. polar and/or ionic substances
hydrophobic
repels water, NOT soluble in water eg. non-polar substances, lipids
hypertonic
solution that is higher in concentration
hypotonic
solution that is lower in concentration
ion
charged particle created when atoms lose or gain electrons
isomer
compounds or molecules with the same chemical formula but different arrangement of atoms (different structure)
isotonic
solutions with the same concentration
isotope
atoms of the same element with different masses (due to differing number of neutrons)
latent heat
A measure of the amount of heat absorbed or released by a substance during a change of state
matter
Anything that has mass (eg. grams) and takes up space (eg. volume). All elements, compounds and mixtures are example of matter
mixture
A substance made up of two or more different elements/compounds that occupy the same space but are NOT chemically combined
molar mass
The mass of 1 molecule of a substance = formula mass in grams
molecule
two or more atoms chemically combined to form a stable nucleus
monosaccharide
A simple sugar eg. glucose, fructose, galactose
containing only 1 sugar unit
neutral
has no charge
neutralisation
A chemical reaction occurring between acids and bases that forms water and a salt (both neutral products)
neutron
A particle in the nucleus of an atom that weighs the same as a proton but has NO charge (neutral)
non-polar
A covalent molecule that has no separation of positive and negative charges eg. electrons are equally shared/distributed
Non-polar molecules are hydrophobic
osmosis
The passive movement of water through a semipermeable membrane following its own concentration gradient
passive transport
The movement of p[articles across a semi-permeable membrane that does NOT use cellular energy
phagocytosis
the process of ‘cell eating’ to absorb something into a large vesicle
pinocytosis
a type of endocytosis of fluids. ‘cell drinking’
polar
a covalent molecule in which the electrons are unequal shared creating small charges. Polar molecules are soluble in water (hydrophilic)
Polymer
A very large molecule made up of lots of repeated units (monomers)
polysaccharide
A carbohydrate made up of a long chain of glucose molecules eg. starch, cellulose, glycogen
proton
positively charged particle in the atomic nucleus
radioisotope
An atom or isotope with an unstable nucleus that spontaneously decays and emits radiation
saturated
in organic molecules, the chemical bonds between C-C are all single bonds
solute
the smaller amount of solid, liquid or gas particles dissolved in a solvent
solution
A common type off mixture, contains a solute dissolved (small particles suspended) in a solvent
solvent
The larger amount of liquid or gas particles in which other particles are dissolved
specific heat capacity
A measure of the heat/energy needed to raise the temperature (kinetic energy of particles) by a given amount, usually 1 degree celsius
sublimation
The process of a change int eh state of matter from a solid to a gas without a liquid state
surface tension
the cohesion of water molecules;es to each other due to the polarity of water and formation of H-bonds
transcription
The process by which a gene in one strand of DNA is ‘copied’ by forming mRNA strand that carries the instructions for making a protein to ribosomes
translation
The process by which an mRNA strand is read and translated into the amino acid sequence for protein synthesis by a ribosome
unsaturated
An organic molecule that contains one or more double or triple C=C bonds
