molecular building blocks Flashcards
what are the main elements of life
hydrogen
oxygen
carbon
nitrogen
phosphorous
at what temperature is the maximum density of water
4 degrees celcius
what are the characteristics of living organisms (6)
made from one or more cells
capable of reproduction
respond to the environment
adapt and change
require a source of energy
growth & development
what are the levels of organisation of a chemical
atom –> molecule –> macromolecule
what is an atom
the simplest level of a chemical
what is a molecule
two or more atoms
what is a macromolecule
large, complex biologically important molecules inside cells made from simple molecules such as sugars, lipids and amino acids
most are polymers
what functions do macromolecules have
osmotic
structural
optical
enzymatic
and more
what are the structures of macromolecules like
very heterogenous - not from the same source
specific conformations are associated to definite functions
examples of macromolecules (5)
haemoglobin
DNA
glycogen
rhodopsin
collagen
what are organelles
aggregates of macromolecules used to carry out a specific function in the cell
examples of single cell life
bacteria
simple fungi
amoeba
what can multicellular organisms do (3)
specialise their cells
intercellular communiation
differentiation
what is the function of water
acts as a solvent
best at dissolving iconic and polar compounds
describe the polarity of water
the electron density is uneven
because of oxygen
so it has electronegativity
at what temperature range is water liquid
0 too 100 degrees celcius
describe the bonding in water
hydrogen bonding
electronegative atoms eg O or N can attract H atoms from other molecules
partial sharing of this proton leads to a mutual attraction between the two atoms
not a covalent bond
weak
important in protein and DNA structures and responsible for the unusual properties of water
what does water not interact with
non-polar substances
lipids
aromatic groups
hydrophobic compounds
what is the general formula for carbohydrates
Cn(H20)n
what are monosaccharides
chain of carbons, hydroxyl groups, one carbonyl group
eg glucose
what structure do monosaccharides exist as
and why
ring structures
because the aldehyde or ketone groups react with a hydroxyl group of the same molecule
what are amino sugars
they contain an amino (NH2) group
they are often acelyated
eg glucosamine
what are the 4 types of sugar derivatives
aminosugars
alcohol sugars
phosphorylated
sulphated
give an example of an alcohol sugar
sorbitol
what are phosphorylated sugars
they contain phosphate groups
eg glucose 6 phosphate
what are sulphated sugars
they contain sulphate groups
eg heparin, chondroitin sulphate
they can absorb a large volume of water
how are glycosides formed
the hydroxyl group of a monosaccharide reacts with an OH or NH group to form a glycoside with a glycosidic bond
what are the 2 types of glycosidic bonds
O - glycosidic bonds
N - glycosidic bonds
what do O glycosidic bonds form
disaccarides, oligosaccarides and polysaccarides
where are N glycosidic bonds formed
nucleotides and DNA
what are oligosaccharides
disaccharides that contain 2 monosaccharides joined by an O glycosidic bond
they contain 3 - 12 monosaccharides
they are products of digestion of polysaccharides or part of complex lipids/proteins
what are polysaccharides
they are formed by thousands of monosaccharides joined by glycosidic bonds
eg starch & glycogen
what is the energy storage in plants
starch
what is the energy storage in animals
glycogen
what are proteogylcans
long unbranched polysaccharides radiating from a core protein
what makes up the ECM
proteoglycans and proteins such as collagen
what are fatty acids
lipids
have a straight C chain (mostly 16-20) with a methyl group and a carboxyl group at the ends
what is the trend of the melting group in fatty acids
decreases with degree of unsaturation (fluidity)
what are 5 common unsaturated fatty acids
palmitoleic acid
oleic acid
linoleic acid
linolenic acid
arachidonic acid
what are unsaturated fatty acids
contain double bonds between carbon atoms
what are saturated fatty acids
contain no double bonds between carbon atoms
what are phosphoacylglycerols
they derive from phosphatidic acid
they are formed from fatty acids esterified to glycerol and phosphorylated at C3
what are sphinogolipids
they derive from ceramide (serine, palmitic acid and another fatty acid)
what are eicosanoids
synthesised from fatty acids with 20 C with 3,4,5 double bonds
they have major biological functions
what forms a nucleotide
nitrogenous base
sugar
phosphate
what are nitrogenous bases
they have N which can take up a sugar
what are examples of nucleotides (3)
nucleoside monophosphate (NMP)
nucleoside diphosphate (NDP)
nucleoside triphosphate (NTP)
what is the structure of an amino acid
carbon with
carboxyl group
amino group
side chain with R groups
what determines the charge of an amino acid
it is determined by all 3 components
it changes with the pH of the environment
what determines the polarity of an amino acid
the side chain determines polarity (hydrophilicity) or nonpolarity (hydrophobicity)
give 5 examples of amino acids
serine
glutamic acid
leucine
tyrosine
lysine
what is the dissociation of amino acids
at different pH carboxyl and amino groups are ionised (charged)
some amino acids also have ionisable side chains
what are non-polar amino acids
they are hydrophobic
give 6 non polar amino acids
glycine
alanine
proline
valine
leucine
isoleucine
give 5 polar amino acids
methionine
cysteine
glutamine
serine
threonine
give 3 aromatic amino acids
phenylalanine
tyrosine
tryptophan
what is a peptide bond
a bond between amino acids to form proteins
formed via condensation reaction which releases water
what determines folding of a protein
charged interactions
flexibility
physical dimentions
give 4 examples of protein structure-function relationship
immunoglobulins
fibrous proteins: collagen
enzymes
channel and carrier proteins, receptors and neurotransmitters
