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Unit 1: Biological molecules - Coggle Diagram
Unit 1: Biological molecules
monomers and polymers
monomers - small repeating units from which larger molecules are formed
monosaccharides, amino acids, nucleotides
polymers - molecules made from a large number of monomers joined together.
can be broken down in a hydrolysis reaction
formed in a condensation reaction
Carbohydrates
Monosaccharides - glucose, galactose and fructose
glucose - alpha and beta
disaccharides = maltose, lactose and sucrose
polysaccharides = starch, glycogen and cellulose
starch
glycosidic bonds a 1,4 and 1, 6
plants
insoluble
branched
glycogen
glycosidic bonds a 1,4 and 1,6
animals
insoluble
branched
cellulose
glycosidic bonds B 1, 4
plants
microfibrils
cell wall
Benedicts test - reducing + non reducing sugars
Lipids
emulsion test
triglycerides
1 glycerol, 3 fatty acids
phospholipid
1 glycerol, 1 phosphate group, 2 fatty acids
head = hydrophilic
tail = hydrophobic
fatty acids
saturated = single carbon carbon bond
unsaturated = double carbon carbon bond
Proteins
many proteins are enzymes
induced fit model
substrate does not fit perfectly
active site changes shape allowing substrate to bind
inhibitors
competitive - bind to active site
non competitive - bind to allosteric site, which alters the shape of the active site and therefore prevents the substrate from binding to it
factors affecting rate of reaction
temperature
substrate concentration
pH
enzyme concentration
inhibitors
rate = change/ time
general properties of proteins
peptide bond in a condensation reaction
protein structures
primary
secondary
tertiary
quaternary
biuret test
H2N = amine group
COOH = carboxyl group
R = variable side chain
RP1
variables
IV - pH
DV - time taken for film to go clear
Control variables - size of photographic film, volume of buffer solution, volume of trypsin solution
Investigation into the effect of a named variable on the rate of an enzyme-controlled reaction.
Nucleic acids are important information-carrying molecules
structure of DNA and RNA
similarities
4 complementary bases
Sugar and a phosphate
Phosphodiester bonds
A, C, G
differences
DNA= double stranded, RNA= single stranded
DNA= deoxyribose sugar, RNA= ribose sugar
Uracil replaces thymine in DNA
RNA strands are shorter than DNA
1 type of DNA, 3 types of RNA
DNA replication
semi conservative replication
Each new DNA molecule contains one strand from the og DNA molecule
Condensation reaction join the new nucleotides catalysed by DNA polymerase. New hydrogen and phosphodiester bonds are formed
Free floating DNA nucleotides are attracted to their complementary bases
DNA helicase breaks the hydrogen bonds between bases. DNA unwinds to form 2 single template strands
ATP
adenine, ribose and 3 phosphate
ADP + Pi -> ATP synthase -> ATP
ATP-> ATP hydrolase -> ADP + Pi
nucleotide derirative
Water
solvent
chemical reactions can occur in the cells
ions and polar substances will dissolve in it
metabolite
transport of substances
tension + cohesion
mass transport of plants
hydrogen bonds
latent heat of vaporisation
evaporation of sweat
In order to change state (from liquid to gas) a large amount of thermal energy must be absorbed by water to break the hydrogen bonds and evaporate
specific heat capacity
buffers changes in temp
lots of energy needed to raise temp
inorganic ions
Inorganic Ions have a charge (positive or negative)
Contain no carbon
They are in solution in cytoplasm and bodily fluids
Each ion has a specific role
examples
More H+ ions = lower pH
Na+ ions transport glucose and amino acids alongside sodium ions
Fe2+ ions bind to the oxygen in haemoglobin
Phosphate ion attached to another molecule = phosphate group