Biochem- Macromolecules and General Principles of Proteins Flashcards
Primary structure or Proteins, types of stabilizing bonds
linear sequence of AA’s in a peptide, stabilized by peptide bonds ( includes disulfide bonds)
secondary structure of proteins, types of stabilizing bonds
local structure of nonbonding AA’s, stabilized with H bonding, includes alpha helices and Beta sheets
tertiary structure of proteins, types of stabilizing bonds
further folding of protein onto itself, forms 3 dimensional shape, stabilized by hydrophobic interactions, acid-base interactions (salt bridges), H bonds and disulfide bonds
quaternary structure of proteins, types of stabilizing bonds
2 or more protein chains bonded together by peptide bonds ( noncovalent bonds)- protein has multiple subunits
what amino acid forms disulfide bonds?
2 cysteine molecules are oxidized and create a covalent bond
How does proline affect protein structure?
disrupts secondary structures
what is denaturation?
loss of 3 dimensional structure ( tertiary), inactivates protein
what type of reaction forms a peptide bond?
condensation / dehydration
what type of reactions breaks a peptide bond?
hydrolysis
what is a peptide (amide) bond?
bond between carboxyl group of one amino acid and the amino group of another amino acid
How many carbons are in a pyranose CHO ring?
6
how many carbons are in a furanose CHO ring?
5
which type of chiral naming system is used for sugars and carbs?
L- D system
How can you tell if 2 sugars are enantiomers? what are their configurations?
D- and L- forms of the same sugar= enantiomers
what are diastereomers?
nonsuperimposable configurations of molecules with similar connectivity, differ at at least one, but not all chiral carbons
what is an epimer?
subtype of diastereomer, differ at exactly 1 chiral center
what is an anomer?
subtype of epimers, differ at an anomeric carbon
what is an anomeric carbon?
new chiral center formed from a ring closure, it was the carbon containing the carbonyl in the straight chain form
what are alpha and beta anomers? ( cis/trans)
alpha anomers have -OH on the anomeric C trans to the free -CH2OH group , alpha oriented down
beta anomers- have -OH on the anomeric C cis to the free -CH2OH group , beta oriented up
what are glycosidic linkages?
connect anomeric carbons from one sugar to link to another sugar, forming complex CHOs, form between monosaccharides and alcohols
what are the common disaccharides and what types of linkages do they have ( alpha vs beta, 1-2 vs 1-4)? What monosaccharides are they formed from?
sucrose (glucose-a-1,2-fructose)
lactose (galactose-b-1,4-glucose)
maltose (glucose-a-1,4-glucose)
what are the 3 forms fatty acids exist in?
triglycerides, phospholipids, cholesterol
what are the 3 ketone bodies
acetone, acetoacetic acid, B-hydroxybutyrate
Is R configuration clockwise or counterclockwise?
R= clocwise rotation, S= counterclockwise rotation
general structure of nucleotides?
5 C sugar, nitrogenous base and an inorganic phosphate
what type of bond attaches nucleotides to form nucleic acids?
phosphodiester bonds
what are nucleosides? How do they form nucleotides?
nitrogenous base and 5 C sugar, attach to Pi to form nucleotides
which nitrogenous bases are purines?
adenine and guanine
which nitrogenous bases are pyrimidines?
uracil, thymine, cytosine
how many rings are in purines vs pyrimidines?
purines= 2 fused rings, pyrimidines= 1 ring
which bonds hold together DNA strands by bonding together nitrogenous base pairs?
hydrogen bonds
How many bonds form between A and T base pairs?
2 H bonds
how many bonds form between G and C base pairs?
3 H bonds
where can RNA be found in the cell ?
nucleus, cytoplasm, ribosomes
where can DNA be found in the cell?
mitochondria and nucleus
which type of bond is broken during DNA denaturation?
H bonds
What is DNA hybridization?
reannealing , single complimentary DNA strands stick tightly and reform double stranded DNA
