CBI5 - Structure and Function of Biomolecules Flashcards
Name four types of biomolecules.
Lipids, polyaschharides, nucleic acids, lipids.
What are the two types of monosaccharides.
Aldose and ketone.
What is the typical empirical formula of carbohydrates.
(CH2O)n
Define difference between aldose and ketone.
Aldose has carbonyl group at end of chain. Ketose has aldehyde group in middle of chain.
Define monosaccharide.
Monomer of sugar or carbohydrates.
How many stereocentres does a carbohydrate usually contain.
Multiple.
What is a Fischer projection.
Three dimensional drawing of carbohydrate molecule.
Define difference between pyranose and furanose.
Pyranose is cyclic monosaccharide with OH below ring. Furanose is cyclic monosaccharide with OH above ring.
Define Haworth projection.
Planar ring structure of cyclic monosaccharide.
Define difference between alpha and beta anomers.
Alpha anomer has OH group on opposite side of new stereocentre. Beta anomer has OH group on same side of new stereocentre.
What is a disaccharide and how do they form.
Two monosaccharides joined together via glycosidic bond in a condensation reaction.
Name three types of polysaccharide.
Starch. Cellulose. Glycogen.
What type of bond is present in glycogen.
1-6 glycosidic bond.
What is present in both starch and glycogen.
Amylopectin.
What two structures are present in starch and what bonds do they have.
Amylose and amylopectin.
Amylose - 1,4-glycosidic bond.
Amylopectin - 1,6-glycosidic bond.
Give three functions of carbohydrates.
Structure. Energy storage. Post translational modification.
How do carbohydrates act as post translational modifications.
Initial glycolsylation occurs in ER lumen.
What are the 5 types of lipids.
Fatty acids. Triglycerides. Sterol lipids. Sphingolipids. Glycerophospholipids.
What is a fatty acid.
Long hydrocarbon chain with COOH group.
What are the two notations for double bonds in fatty acids.
IUPAC/C- or w-/n-.
What kind of isomerism is present in unsaturated fatty acids.
E/Z isomerism due to C=C which has restricted rotation.
Define a triglyceride.
Three fatty acids bonded to glycerol molecule via condensation reactions forming three Ester bonds.
Define glycerophospholipids.
Glycerol with two fatty acids and phosphate head. Multiple head groups possible resulting in differing characteristics.
Define major property of all lipids.
Amphiphilic allowing lipid aggregation.
What is a sphingolipid.
Phospholipid with sphingoid base backbone.
Name three types of sphingolipid.
Sphingomyelins. Gangliosides. Cerebrosides.
Where are spingomyelins found and discuss structure.
Found in myelin sheath. Contain phosphate group bound to choline or ethanolamine.
Where are cerebrosides found and discuss structure.
Neurone membranes. Contain monosaccharide head group.
Where are gangliosides found and discuss structure.
Found in lipids in the brain. Oligosaccharide head group.
What are sterol lipids derived from.
Cyclopentaperhydrophenanthrene.
Most common type of sterol lipid.
Cholesterol.
What three structures from due to lipid aggregation.
Micelles. Vesicles. Lipid bilayers.
Define Tm.
Temperature at which solid membrane becomes liquid.
Define difference between lateral and transversal diffusion in a lipid bilayer.
Lateral diffusion involves molecules diffusing within their leaflet. Transversal diffusion involves molecules diffusing between the two leaflets (does not occur commonly).
Define difference between nucleotide and nucleoside.
Nucleoside is sugar and nitrogenous base. Nucleotide is sugar, nitrogenous base and phosphate group.
Give three functions of nucleotides.
Energy units. Second messengers. Enzyme substrates.
What are the four types of amino acids.
Acidic, basic, neutral polar and neutral non polar.
Which amino acid doesn’t have a stereocentre.
Glycine.
What is the role of chaperone proteins in protein folding.
Proteins that facilitate the folding of other proteins.
Define a cofactor.
Additional non protein compounds that facilitate functioning of proteins.
What are the three types of column chromatography used for bio analysis.
Size exchange chromatography.
Ion exchange chromatography.
Affinity chromatography.
Name three methods of protein purification.
French press - pressing cells though small gaps at high pressure.
Repeatedly freezing and thawing cells using liquid nitrogen.
Dissolving membrane using detergent and spreading soluble part from debris.
How does SEC work.
Separates molecules dependent on size. Beads attached to inside of column.
Discuss IEX.
Ion exchange chromatography. Serpentes molecules depending on charge. Can be used for cations or anions.
How does AC work.
Similar to IEX about more specific. Tag added to the protein which is detected.
Discuss general process of SDS-PAGE.
SDS added to proteins giving negative change. Move through gel towards positive charge. Coloured with Coomassie blue to be shown on gel membrane.
Give names of carbohydrates based on number of carbon atoms.
3 - triose. 4 - tetrose. 5 - pentose. 6 - hexose. 7 - heptose.
How to determine D or L configuration in sugars.
Look at asymmetric carbon atom furthest from aldose/ketone functional group. If OH is on left, L isomer. If OH is on right, D isomer.
Common name for sucrose.
Caster sugar.
Name four types of fatty acids in terms of length.
Short chain fatty acids (SCFAs) - 1-5.
Medium chain fatty acids (MCFAs) - 6-12.
Long chain fatty acids (LCFAs) - 13-21.
Very long chain fatty acids (VLCFAs) - 22+.
Highest number of car bonds in a fatty acid chain?
Approx 24.
Which isomer is unsaturated fatty acids reduces packing.
Z isomerism as it causes a kink to the structure.
Give notation for 16-carbon fatty acid with 1 double bonds at 8th carbon from methyl end.
w/n-8
16:1
Where are triacylgycerols commonly found.
Adipocytes or lipocytes. Fat cells.
Discuss how cholesterol is amphiphilic using structure.
Ring system - hydrophobic.
OH - hydrophilic.
Define chromatography.
Method of isolation using stationary phase that interacts with molecules running through it and mobile phase.
What are the monomers used for SDS-PAGE gel formation. Why is one monomer only not used.
Mixture of acrylamide and bisacrylamide to form gel structure. Acrylamide solely would produce long chains of polymer instead of gel mesh structure.
