life chemistry & principle of the pH scale Flashcards
Atom
An atom is the smallest unit of matter that retains all of the chemical properties of an element
element
A substance that cannot be decomposed into simpler substances by chemical means, and is made up of atoms all with an identical number of protons
molecule
a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
electrolyte
A substance that breaks up into ions (particles with electrical charges) when it is dissolved in water or body fluids
compound
unique substance that consists of two or more elements combined in fixed proportions
main inorganic chemical symbols and fomulae for the main inorganic chemicals found in the body
inorganic means they lack C-H bonds
water - H20
oxygen - O2
Carbon dioxide - CO2
sodium chloride - NaCl2
hydrochloric acid -HCl
main organic compounds found in the body
carbohydrates
lipids
proteins
nucleotides
Carbohydrates
sugar and starches.
contains carbon, oxygen and hydrogen
main carbohydrate is the monosaccharide glucose, which is used during both types of respiration.
functions:
provides energy to fuel cell metabolism
provides an energy storage - eg. glycogen
forms an integral part of the structure of DNA and RNS
acts as receptors on cell surface allowing the cell to recognise other molecules and cells.
Glucose (alpha and beta) structure
amino acids
always contain hydrogen oxygen and nitrogen and many carry metals in addition. in humans amino acids have a common structure, with an amino group (NH2) a carboxyl group (COOH) and a hydrogen atom. what makes amino acids different from each other is the length of the side chain. Amino acids are the building blocks for protein
proteins
made from many amino acids. Proteins are very specific. It helps repair and build your body’s tissues, allows metabolic reactions to take place and coordinates bodily functions. In addition to providing your body with a structural framework, proteins also maintain proper pH and fluid balance.
examples of different proteins (4)
carrier molecules (eg. haemoglobin)
enzymes
many hormones (eg. insulin)
antibodies
when can protein be used as an alternative energy source
in starvation
protein primary structure
the linear sequence of amino acids in a peptide or protein.
protein secondary structure
regular, recurring arrangements in space of adjacent amino acid residues in a polypeptide chain. It is maintained by hydrogen bonds between amide hydrogens and carbonyl oxygens of the peptide backbone. The major secondary structures are α-helices and β-structures.
protein tertiary structure
the overall three-dimensional arrangement of its polypeptide chain in space. It is generally stabilized by outside polar hydrophilic hydrogen and ionic bond interactions, and internal hydrophobic interactions between nonpolar amino acid side chains
diagram to show proteins different structures
protein quarternary structure
the association of several protein chains or subunits into a closely packed arrangement. Each of the subunits has its own primary, secondary, and tertiary structure. The subunits are held together by hydrogen bonds and van der Waals forces between nonpolar side chains.
lipids
diverse group of substances consisting of mainly carbon, hydrogen and oxygen atoms (some contain additional elements like nitrogen or phosphorus). common property is being hydrophobic.
most important groups of lipids (5)
fats (triglycerides)
phospholipids
certain vitamins
prostaglandins
steroids
fats (triglycerides)
stored in adipose tissue as an enrgy source . role is to insulate the body and protect the organs.
fat structure
contains 3 fatty acids attached to a molecule of glycerol can be either saturated (straight chain) of unsaturated (bent chain)
phospholipids
form a phospholipid bilayer round the cell surface membrane, providing a water reppellent barrier, separating the cell contents from its environment
what certain vitamins are fat soluble?
vitamins A, D, E and K
