Cellular biochemistry Flashcards
macromolecules are usually __ that consists of repeating units called __
- polymers 2. monomer
what do we called if a polymer consist of one type of monomer?
homopolymer
what do we called if a polymer consists of more than 1 type of monomer?
copolymer/terpolymer/heteropolymer
complete statement below:
Protein’s polymer called _. It is monomers of __. there are __ types of amino acids
- polypeptide
- amino acid
- 20
amino acids are linked by peptide bond which result in ?
condensation reaction
what is peptide bond?
covalent bond that links amino acid via a condensation process (removal/loss of water molecule).
how to form protein?
amino acids are linked by dehydration synthesis to form peptide bonds
amino acid consists of?
amino group, a carboxylic acid group, hydrogen atom and R group all surrounding C atom (alpha carbon)
in glycine, the simplest amino acid, the R-group is
a. oxygen atom
b. hydrogen atom
b
which is true about glycine?
- smallest amino acid
- side chain is H atom
- alpha carbon show chiral behavior
- not flexible
1 and 2
which amino acid is acidic: hydrophilic and charged?
aspartic acid (carboxy methyl chain) and glutamic acid(carboxy ethyl chain)
which amino acid is basic: hydrophilic and charged?
lysine(amino butyl side chain) and arginine(imidine contain side chain)
which amino acid is hydrophilic and not charged?
aspargine(amide side chain), glutamine(Amide side chain), serine(hydroxy methyl side chain), threonine(1-hydroxy ethyl side chain) and tyrosine(p-hydroxy phenyl methyl side chain)
why is tyrosine is very hydrophilic and might act as hydrophobic if buried in middle protein
because it has hydroxyl attached to an aromatic ring
which amino acid is hydrophobic (nonpolar) with aromatic ring?
phenyl alanine, tryptophan and histidine(but it’s hydrophilic)
which amino acid is hydrophobic without aromatic ring?
alanine, valine, leucine, isoleucine
which amino acid is contain sulfur?
cysteine(thio methyl side chain) and methionine(methyl thio ethyl side chain) (usually react as unreactive hydrophobic residue)
how to form disulphide bridge of cystine and what is the function?
two cystein placed some distance apart along a polypeptide chain/ forming part of different chain can be joined by oxidation. it is sto stabilize protein structure
why disulphide bond?
disulphide bond increase the conformational stability mainly by constraining the unfolded conformations of protein and decreasing their conformational entropy
what is the function of sulfur atom in methionine?
it is unreactive and serves no function other than imposing a special configuration on aliphatic sidechain but in cytochrome c it form the link between protein and heme iron
what is imino acid?
compound that has-NH- group as part of a ring rather than NH2 (proline)
at what physiological pH does amino acids have at the zwitterion state?
pH 7.35~7.45
what is the functions of protein?
enzyme, storage protein, transport protein, contracting protein(muscle), regulatory protein, toxin, hormone, structural protein
what is the level of protein structure?
primary, secondary, tertiary, quaternary
explain primary structure of protein
structure due to covalent bonding i.e the sequence of amino acids linked by peptide bond.
explain secondary structure of protein
folding of polypeptide chain due to formation of hydrogen bond between peptide group which link amino acid together
what are the two types of folding in the secondary structure of protein?
alpha-helix and beta-pleated/sheet (thermodynamically most stable structures)
