Topic 1 - Biological Molecules Flashcards
Monomers
Small molecules that are the building blocks of polymers
Polymers
Long molecule made up from many smaller molecules
Carbohydrates monomer and polymer
Monomer - Monosaccharides
Polymer - polysaccharide
Proteins monomer and polymer
Monomer - amino acids
Polymer - proteins/polypeptide
Fats/ lipids monomer and polymer
Monomer - triglycerides
Nucleic acid monomer and polymer
Monomer - nucleotides
Polymer - DNA/RNA
Condensation
When two molecules join together to form one large molecule and one molecule of water
Glycosidic bond
Every bond between molecules in carbohydrate
Hydrolysis
When two molecules are split apart using a molecule of water
Disaccharide formations
Glucose + Glucose = maltose
Glucose + Fructose = sucrose
Glucose + Galactose = lactose
Glucose
C6H12O6
Two forms:
Alpha glucose HO-OH
Beta glucose HO-H
Polysaccharide
Many monosaccharides joined together in a condensation reaction
Cellulose
> in a plant cell wall > Beta glucose > glycosidic bonds > unbranded/ straight chain > string structure for plant cell walls > insoluble > microfibrils and hydrogen bonds
Starch Amylose
Plants: glucose/ energy storage > alpha glucose > unbranded and coiled > compact storage of glucose > insoluble: doesn’t effect water potential (no effect on osmosis)
Starch - Amylopectin
Plant: glucose/ energy storage
> alpha glucose
> glycosidic bods
> branched, increase the surface area so it can be hyrodlysed faster
> insoluble: no effect on water potential and no effect on osmosis
Glycogen
Animals: glucose/ energy storage
> alpha storage
> glycolic bonds
> very branched bigger surface area faster hydrolysis
> insoluble no effect on water potential or osmosis
Carbs test
Benedicts test: Reducing sugars 1) Add benedicts BLUE 2) Heat sample in water bath 3) if sugar is present turn RED
Non-reducing sugars
1) Add hydrochloric acid
2) boil in water bath
3) neutralise with sodium hydrogen carbonate
4) test againfor a reducing sugar
Triglyceride
Three fatty acids
Glycerol molecule
Formed in a condensation reaction, make ester bonds
Saturated and unsaturated fatty acid
Saturated- NO double bonds between carbon
- increase in cholesterol and LDL’s
Unsaturated - HAS double bonds between carbon atoms
- less hydrogen
- polyunsaturated = more than one double bond
Triglyceride function and structure
Energy storage
Long polymer
Insoluble
Form insoluble droplets
Phospholipids function
Forms cell memebrane
Hydrophobic tails face inwards
Middle is hydrophobic, difficult for polar H2O to diffuse in or out
Lipids test
Emulsion test
1) mix substance with ethanol
2) add water
3) milky emulsion formed then lipids present
Protein
A polymer built up of one or more amino acid
Amino acids
Monomer that makes up proteins
Peptide bond
The bond between amino acids in ALL proteins
Types of protein
Enzyme
Antibodies
Transport
Structure
Protein test
Biuret test
1) add biuret reagent BLUE
- copper sulfate
- sodium hydroxide
2) if the protein is present goes purple/lilac
Primary structure
Sequence of amino acids
Peptide bonds
Secondary structure
The long chains of amino acids fold into regions with repeating patterns (alpha helix, beta pleated sheets)
Peptide bonds and hydrogen bonds
Tertiary structure
The final 3D resting shape of the protein
Peptide bonds, hydrogen bonds, ionic bonds, disulphides bridges
Quaternary structure
Proteins made from more than one polypeptide
Peptide bonds, hydrogen bonds, ionic bonds, disulphides bridges
Protein shape question
Tertiary structure of the active site is complementary to the shape of the substrate and forms enzyme-substrate complex
Non-functional protein
Mutation: Change in primary structures changes tertiary structure
Denatured: changes ionic bond, changes tertiary structure
Temperature effecting enzymes
1) As temp increases molecule vibrates
- More collisions, higher activation energy, e-s-c formed
2) molecule breaks vibrate and break internal bonds
3) ionic and disulphide bridges change active site shape
4) denatured
Denatured
A permanent change to the active site which means no more enzyme complex’s are formed
Factors affecting enzyme activity - pH
> have optimum pH > increase and decrease the pH away from the optimum > enzyme activity decrease > oh- or H+ will interact with the hydrogen bonds or ionic bonds > change 3 structure > change active site > less e-s-c > denatured
Enzyme concentration affecting activity
> increase conc
rate reaction increases
more collisions
substrate concentration becomes limiting factor
Substrate concentration
Increase substrate conc Rate of reaction increase More collision Until active sites occupied Enzyme conc is limiting factor
Competitive inhibitors enzyme activity
> competitive inhibitors have similar substrate shape
bind to active site
stops substrate forming
Non-competitive inhibitors
> bind to enzyme but no active site
Changes the shape of active site
no more e-s-c formed
Nucleotides
The monomer that makes up polynucleotides
DNA deoxyribose nucleic acid
> Double stranded = double helix > Long polymer > Carries the genetic information which codes for proteins > Adenine, Thymine, Guanine, Cytosine > deoxyribose, base, phosphate
RNA
> Ribonucleic acid > single stranded > short polynucleotide > ribosome formed from RNA and proteins > transfers genetic code from DNA to ribosomes in the cytoplasm
Polynucleotide
A with T C with G > phosphodiester bonds between phosphates > Sugar phosphate backbone > antiparallel
Semi conservative replication
> DNA antiparallel
nucleotides on each strand arranged differently
active site of DNA polymerase has specific tertiary structure
- DNA helicase breaks H bonds
- both starts act as templates
- free nucleotides, complementary base pairing
- DNA polymerase forms phosphodiester bonds
- H bonds reform
- one new and one original strand
Proving semi conservative replication
> Done by Meselson and Stakl
population cultured in a growth medium containing heavy nitrogen only (centrifuged only one heavy band observed)
Cells transferred to a medium with only light nitrogen (one replication band was twice thickness)
two replications in light nitrogen (intermediate and light band)
DNA sense strand
> contains genes
> does NOT act as the template for mRNA
DNA Antisense strand
> template strand
acts as template fo mRNA
complementary to genes on the sense strand
Pre-mRNA
Same as DNA sense strand
U replaces T
Splicing
pre-mRNA to mRNA
Introns are removed
ATP uses
> breaks down energy in small amounts
broken down in one reaction (rapid release)
easily resynthesised
ass phosphate to other molecules
ATP equation/reaction
ADP + Pi ——————> ATP
ATP = condensation and ATP synthase
ADP + Pi = hydrolysis and ATP hydrolase
Extra ATP
Hydrolysis of ATP to ADP and Pi can be coupled up to energy requiring reactions within cells
Inorganic phosphate is released which can be used to phosphorylate other compounds
Water structure
> polar molecule
positive and negative end
poles are attracted to each other (H+ bonds between all molecules)
Solvent
A liquid that other substances can dissolve in
Ionic compounds and water
> Ionic compounds are made form positive ions and negative ions > water has positive and negative end
ionic compounds dissolve in water because all the small charges of water add up together
Water as a metabolite
Water is important in metabolic reactions like condensation and hydrolysis
Water for transport
Cohesion allows water go move upwards
Responsible for surface tension when water meets air
Cohesion
Water molecules stick to each other because of their hydrogen bonds
High latent heat of vaporisation
Lots of energy needed to break hydrogen bods between molecules
High specific heat capacity
Takes lots of energy to heat up or to cool down water because of the hydrogen bonds between its molecules
(Aquatic environments are stable, so are bodies)
Ion
An atom that has lost or gained elections
Inorganic
A compound that doesn’t contain carbon
Positive ion
Cation
Negative ion
Anion
Inorganic ions location
> occur in the cytoplasm and body fluid
pH (inorganic ions)
PH is measure of h+ in solution
H+ ions are very reactive
> react with protein (change tertiary structure)
Sodium ions (inorganic ions)
> important in helping other molecules move across membrane
> co -transport
Iron ions (inorganic ions)
> important n haemaglobin
carry oxygen
haemaglobin is a protein with a 4 structure
Phosphate ions (inorganic ions)
ATP contains phosphate group
RNA and DNA form by condensation reaction between phosphate group and polynucleotide
