Lecture 19&20- proteins and amino acids Flashcards
Proteins are …. linked amino acids formed according to the ….
Cavalently
Genetic code
Proteins are …. of amino acids
Polymers
….. of amino acids creates a peptide bond
Condensation
Resonance hybridisation of the peptide bond
Generates partial charge
Double bond switches between locations
Contributes to protein structure
Peptide bond has some ….. mobility
Rotational
Movement of amino acids rotates around C-C and N-C bonds
Rotation depends on steric potential and depends on steric clash
C-C angle of rotation is called …
Psi
N-C bond rotation is called …
Phi
Chains of amino acids in peptide bonds fold into proteins by ….
non covalent forces
Proteins fold into a conformation of ….
Lowest energy
(lost free energy, low ability to occupy different spaces)
Purifies protein is denoted by being exposed to a ….
The denatures protein reforms original protein by…
High concentration of urea
Removing urea
What do protein chaperones do?
Ensure proteins obtain and maintain correct shape
Viruses hijack cells.When the virus infects a bacterial cell it’s genes are transcribed and translated. The virus proteins fold by ………….
Hijacking the bacterial cell’s chaperones
Alpha helix overview
Most commonly occurring protein secondary structure
Very energetically favourable fro any amino acid sequence due to peptide backbone interactions
Right handed helix
Discovered in keratin
Hydrogen bonds in alpha helix
Key to structure
H-bonds between peptide backbone
R-groups not involved
H-bond between backbone carbonyl (C=O) and Avery 4th amino acid nitrogen
H-bonds make all of the alpha helix dipoles all point the same way causing a mega-dipole
Beta strand/sheet overview
Relys on association with other beta strands
Multiple beta strands form beta sheets
Discovered in silk
