13O- Amino Acids Protien DNA Flashcards
Amino acid chemical properties
Acidic properties, carboxylic acid group loses H+
Basic properties, amine group accepts H+
What’s a zwitterion
Permenant +ve and -ve charge, no overall charge
In acid, line pair on NH2 accepts H+, +ve charged
In alkali, COOH group loses H+, -ve charged
Glycine in acidic conditions
NH3+- CH2- COOH
Glycine in alkali conditions
NH2-CH2-COO-
Properties of amino acid
High MPs and BP, strong ionic bonds between opposite charged ions
Dissolved in water
What’s a protein
Sequence of amino acids, joined by peptide links
What’s a peptide link
Amine group of 1 amino acid reacts with carboxylic acid group of another amino acid
NH-CO
What’s the primary structure of proteins
Sequence of amino acids along a protein chain, held by covalent bonding, relatively stable
What’s the secondary structure of a protein
Protein chain forms a helix (alpha helix) or pleated sheet (beta pleated sheet), held in place by hydrogen bomding between C=O and NH groups, disrupted by pH change or heat
What’s the tertiary structure of a protein
The alpha helix or beta pleated sheet can fold into a 3D shape, held by H bonding, ionic bonds, sulphur-sulphur (disulphide) bonds and van der waal forces, many fold into globular shapes
Why are hydrogen bonds and sulphur-sulphur bonds important in proteins
Proteins are complex shapes, held in position by hydrogen bonds and sulfur-sulfur bonds, these shapes are imperative for their function
What does the hydrolysis of a peptide link produce
Constituent amino acids
How can amino acids be separated and identified
Thin layer chromatography
Glycine + glycine
NH2-CH2-C=ONHCH2COOH
What’s an enzyme
Protein
How do enzymes work as catalysts
Globular proteins
Substrate fits into active site, complimentary shape, bond to active site temporarily through intermolecular forces, these forces promote movement of e- lowering activation energy react, lock and key
What’s a stereo specific active site
Active site only catalyses reactions with one enantiomer as they are specific to substrates
What’s an enzyme inhibitor
Molecule which binds to enzymes active site, blocks the substrate from forming an enzyme substrate complex
What’s computer modelling
Allows for prediction of the shape of a protein before synthesis, predict properties, design drugs for medical conditions
What’s a nucleotide made of
Phosphate ion bonded to 2-deoxyribose bonded to either adenine, cytosine, guanine or thymine
Describe the structure of DNA
Polymer of nucleotides linked by covalent bonds between phosphate group of one nucleotide and the 2 deoxyribose of another, forms sugar phosphate polymer chain, bases attached to sugar in chain
How does DNA have two complimentary strands
Hydrogen bonding can only occur between adenine and thymine, and guanine and cytosine this means that one strand will have another strand with a base sequence it forms hydrogen bonds with
Eg ACT has a complimentary strand TGA
How is a nucleotide bonded
O from OH on phosphate bonds to CH2 (carbon 5) on 2-deoxyribose (H2O molecule lost)
N from NH on a base bonds in place of the OH from 2-deoxyribose (carbon 1) (H2O molecule lost
O from OH on 2-deoxyribose (carbon 3) bonds to the O on a phosphate of another nucleotide (produces H2O)
How can you locate amino acids on a chromatogram (TLC)
Use developing agents ninhydrin or uv light, measure distance travelled by solvent and travelled by spot
Rf= distance moves by spot/ distance moves by solvent
Compare this Rf value to Rf values of known amino acids
What’s cisplatin
Anti cancer drug
What’s the shape of cisplatin and it’s formula
Square planar
Pt(NH3)2Cl2
How does cisplatin work
Ligand replacement reaction, dative covalent bonds from N atoms on two adjacent guanine bases on a DNA strand
Bonding to strands of DNA, distorts their shape, prevents replication of cell
CGATCTTAG
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Pt
(NH3)2
Benefits and adverse effects of cisplatin and why the drug causes adverse effects
Adverse effects- Cisplatin can bond to DNA in healthy cells that replicate quickly
hair cells replicate quickly causing hair loss
Benefits
90% effective in treating testicular cancer, slowing down progression
