October Flashcards
(138 cards)
What is chemistry?
The science of the composition and properties of substances and matter
What is biochemistry?
The science of the chemical and physiochemical processes and substances within living organisms
What is matter?
Anything that has a mass and occupies space
What are the four main elements of the body and their percentages?
Nitrogen - 3%
Hydrogen - 10%
Oxygen - 65%
Carbon - 18%
Why may you not supplement transition metals for a long period of time?
They compete with each other in terms of absorption, so supplementation of one could cause a deficiency of another
What is a free radical?
An atom or molecule with an unpaired electron
What does the element number correspond to?
The number of protons
What happens to the reactivity of the elements as you go down column 1?
It increases
All react with water
What happens to the reactivity of halogens as you go down the column?
It decreases
Fluorine can displace Chlorine which can displace Iodine
What is an isotope?
Atoms of the same element with different numbers of neutrons
When are radioactive substances used in medicine?
PET scans
Radiotherapy
H-Pylori breath test - C13/14 labelled urea
What is an ionic bond?
A bond where one atom donates some of its electrons to another and then they are bonded
What is ionisation?
The process of giving or gaining electrons
Oxidation - loses electrons
Reduction - gains electrons
What is a covalent bond?
When two elements share electrons
What is an electronegative element?
An atom with a large group of protons so they tend to pull electrons towards them
What are polar bonds?
Bonds caused by polarisation of molecules
What features of water are caused by polar bonds?
Surface tension, ability to dissolve many substance
What are hydrophobic molecules?
non-polar molecules that do not dissociate easily in water
What are the four most electronegative elements?
Fluorine, chlorine, oxygen, nitrogen
What is an ion?
A charged atom
What is a universal solvent?
Waters ability to dissolve anything with polar bonds or ionic compounds
What is an electrolyte?
a solution of an ionic compound in water - can conduct electricity
What is an acid?
A substance that releases H+
What is a base?
A substance that binds to hydrogen ions - creates OH-