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Unit 2 - Coggle Diagram
Unit 2
2.5 enzyme
Enzyme:
a globular protein
act as a biological catalyse that speed up the rate of chemical reaction
not consumed by the reactions
can be re-used
substrate:
the molecules the enzyme reacts with
Active site:
the region on the enzyme that bonds to the substrate molecule
active site and the substrate complement each other in both shape + chem properties
Enzyme Catalyse:
occur in aqueous solutions ex cytoplasm
substrate and ezyme are moving randomly in the solution
sometimes can be fixed in position (membrane-bound)= localise reactions to particular site
enzyme catalyse the substrate into product = create an enzyme-product complex
enzyme and product dissolciate and enzyme was not consumbed and reuse
substrate + enzyme's active site = enzyme-substrate comples
Enzyme kinetics:
rate of enzyme catalysis can be inxrease by increasing the frequency of enzyme-substrate collision
rate can be decreased by denaturation
Factors affecting enzyme activity
pH:
enzyme activity is highest at an optimal pH range
activity decreases outside of this range(due to denaturaiton)
Substrate concerntration:
increase enzyme activity (more particles= more collision)
at a certain point, activity plateaus (saturation of active site
temeperature:
increases enzyme activity (more kinteitc energy= more collisions)
enzyme activity peaks at an optimal temperature
higher temperatures decrease activity (causes denaturation)
specificity
Lock and Key model:
enzyme and substrate complement each other precisely (chem property + shape)
active site and the substrate will share specificity
Induced fit model:
active site is not a rigid fit fot the substrate and changes its conformation to better accommodate the substrate
advantages
enzymes exhibit broad specificity
stresses the substrate bonds and induces catalysis
enzyme can be inhibited by other molecules
inhibitors:
fits the activie sites =prevents the substrate from entering
fits into an alloteris sites= causing a conformational change=substracte cannot attach to react
competitive inhibition:
blocks the active site
the higher the concern of inhibitor=the slower the reaction
the same maximum rate of reaction will be achieved if more substrate is added
non competitive inhibotio:
bind to an allosteric site = altered the substrate = cannot react
concern of inhibotors increase = reaction decrease
fewer functional active sites available
industrial enzymes
immobilized enzymes:
fixed to a static surface to prevent enzyme loss = improves the efficiency of the catalysed reaction
seperation of the product is more easily achieved
lactose-free milk
Steps
lactase(enzyme) digests lactose into glucose+ galactose
lactase is bound to an inert substance(alginate beads)
3.milk is passed over this surface to become lactose free
Benefits
provides a source of dairy for lactose-intolerant ppl
increases sweetness of milk
reduces crystallization and production times for cheese
Biotech: involved in processes ex gene splicing
food production: refinement of beers + diary
medicine: identigy conditions (diseases/pregnancy)
tecctile: processing fibres
biofuels: breakdown carbonhydrates to produce ethanol-baed fuels
paper: pulping of wood for paper production
2.2 Water
Water Structure
two hydrogen atoms covalently bonded to an oxygen atom
Hydrogen bonding:
dipolarity of water enables it to form polar associations with other charged molecules
form hydrogen bonds with other water molecules
Cohesive properties: Water can form hydrogen bonds with other water molecules (water sticks)
surfeace tension (resist low level external forces)
Adhesive properties: form polar associations with charged molecules
Allow potential capillary action (transpiration strem in plants)
Solvent properties: a great solvent due to its capacity to dissolve a large number of substances
large quantities of water molecules can weaken forces(ionic bonds) and form hydration shells
substances that can dissolve in water are hydrophilic
glucose
amino acids
sofium chloride
oxygen(low)
substances that cannot dissolve are hydrophobic ex lipis fats and cholesterol
Thermal properties: has the capacity. to absorb large amounts of heat energy before changingn state
hydrogen bonding must be broken
high specific heat capacity
energy required to raise tempt of 1g by 1c
make water an effective coolant
evaporation of sweat requires absorption of heat
Water versus Methane
differ in thermal properties(heat capacity due to hydrogen bond) but having similar structures
2.3 Carbohydrates
Monosaccharides: function as an energy source
glucose
hexagonal ring / fuels respiration
ribose
pentose sugar/ backbone of rna
Galactose
less sweet / found in milk
Fructose
pentose sugar / found in fuits+honey
GGF: gies good flavor
Polysaccharides: monosaccharide are covalently hoined by glycosidic linkages to form polymers
Funtions as storage form
Glycogen
energy storage formed in the liver in animals
composed of a-glucose (1-4+1-6 linkages)
branching
similar to amylopectin in plants + more highly branched
Starch
energy storage found in plants
a-glucose(1-4 arrangement)
glucose molecules oriented in the same way, starch molecules is curved not straight
Amylose
linear molecule (1-4 arrangement)
easier to digest
a-glucose + unbranched = helix
Amylopectin
branched + contains additional 1-6 linkages
harder to digest
takes up less space (globular shape)= prefered storage form in plant
Cellulose
linear molecule made of beta glucose
1-4 arrangement + hydrogen bond
uncranched chains
form bundles calles cellulose microfibrils
high tensile strength
Disaccharide: function as transport form
Sucrose( Fructose + Glucose)
table sugar
Maltose (G+G alpha glucose)
Lactose(glucose alpha +galactose beta)
found in milk
LSM(length support movement)
bonding
1-4 straight chains
1-6 bond
Energy storage: carbonhydrates and lipids are both used as energy storage molecules
Osmotic pressure (lipids easier to store)
Digestion (carbohydrates easier to utilise)
Storage (lipids used for long term)
ATP yield( lipisds sotre more energy per gram)
Solubility (lipids insoluble/ harder to transport)
Body Mass Index=Mass. in Kg / (height in m)^2
2.4 proteins
Amino acids: the monomer of a protein
amine group + Carbon + hydrogen + carboxyl group + R group
linked together to form polypepties + 20 different amino acids that form polypeptides
Peptide bonsd: amino acids are covalently joined by peptide bond to form polypeptide chains
Sequence of amino acids: encoded by genes
THe assembly of polypeptide chain: occurs at the ribosome
Protein structure
Tertiary Structure (globular protein)
three dimensional arrangement
determined by the interactions of the side chain
hydrogen bond
disulphide bridged
ionic interactions
polar associations
Secondary Stucture (ex. fibrous protein)
folding into repeat patterns
alpha helixes occur when amino acid folds into a coil
beta pleated occur when amino acid sequence is directionally oriented
results from hydrogen bonds (amine + carboxylic)
Primary structure
order od amino acid sequence
formed by covalent peptide bonds
Quatary structure (ex haemoglobon )
found in proteins that is consist of more than one polypeptide chain linked tgt
4 poly peptide chains (2 alpha + 2 beta)
Functions of proteins
Sensation (rhodopsin)
Rhodopsin: a pigement in the photorecepter cells of the retinca, detection of light
Movement (actin, myosin)
actin, myosin: filaments involved in the contraction of muscle
Transport (haemoglobin)
haemoglobin: found in red blood cells, transport of oxygen
cytochroms: located in mitochondria invole in electron transport chain
Enzyme (rubisco, catalase)
Rubisco(photosynthesis): involved in the light independent stage of photosynthesis
Immunity (immoglobulins)
immoglobulins: antibodies produced by plasma cells, targeting specific antigens
Hormonal (insulin, glucagon)
Glucagon: produced by the pancreas to increase in blood glucose levels
Insulin: produced by pancreas, triggers a reduction in blood glucose levels
Structure
Spider silk: fibre spun, used to make webs
Collagen: connection tissue of animals
Denaturation: structural change in a protein that results in the loss of its biological properties
Temperature:
high thermal energy = disrupt H bonds
bond broken = protein unfold = lose it function
pH:
amino acids= zwitterions (neutral)
alter the charge of the protein = alter protein solubility
ex stomach protein=acidic
blood protein = neutral pH
Gene polypeptide
Gene: a sequence of DNA that encondes a polypeptide sequence
gene sequence converted to polypeptide sequence
transcription
making an mRNA transcript based on a DNA template (nucleus)
translation
using the instructions of the mRNA transcript to link amino acids tgt (ribosome)
one gene code for one polypeptide Exceptions
genes encoding tRNA sequences are transcribed but never translated
genes may be mutated and produce an alternative polypeptide sequence
genes may be alternativelt spliceed to generatre multiple poly peptide variants
Proteome:
a proteins expressed within in a cell/ tissue. organism at a certain time
proteome of every individual will be unique
-as protein expressions patterns are determined by an individual's genes
proteome is always larger than the number of gene
gene sequences may be alternatively spliced following transcription
to generate multiple protein varaints from a single genes
proteins may be modified in translation to promote further variation
2.1 Molecular Biology
Metabolism: the chemical processes that occur within a living organism in order to maintain life
it is the web of all enzyme-catalysed reactions that occur within a particular cell or organism
Organic compounds: molecules that contain Carbon and are found in living things (exceptions: carbonate cuz contain metal cations)
Carbon atoms have capacity to form four covalent bonds
Biomacromolecules
Class: Protein
Monomer: Amino acid
poolymer: polypeptide
Class: Nucleic acid
Monomer: nucleotide
polymer: DNA/RNA
Clas: Carbohydrate
Monomer: monosaccharide
Polumer: polysaccharide
Lipids are NOT composed of repeating monomers
Class: Triglyceride
Subunits: Glycerol+fatty acid x 3
Type of reactions
Anabolism
involves condensation reactions (water as by products)
ex. phtosynthesis
the synthesis of complex molecules form simpler ones
Catabolism
the breakdown of complex molecules into simler ones
involves hydrolysis reactions (water consumed)
ex. cellular respiration
Vitalism: a doctrine that organic molecules could ONLY be synthesized by living system
living organisms were thought to posses a "vital force" that was used to manufacture organic molecules
Falsification of vitalism: Frederick Woehler disproved the theory by artificially synthesizing an organic molecule
heated an inorganic salr and produce urea (organic)