Midterm Flashcards
(57 cards)
how does the cell membrane maintain life
uses selective permeability to maintain gradients and inequilibrium
metabolism (catabolism vs anabolism)
all chem reactions that maintain cell life.
catabolism: breakdown of molecules to obtain energy
anabolism: synthesis of all compounds need by cell
attributes of all living organisms (7)
cell membrane, metabolic processes facilitated by enzymes, spend energy, react to stimuli, reproduction, mutability, non-equilib (selective permeability)
stereoisomer, chiral center, enantiomer
stereoisomer: 2 molecules w same formula and f.g. but cannot be superimposed
chiral center: center of asymmetry
enantiomer: mirror image
end of monosacharride
carbon of aldehyde or ketone (lowest number convention)
reaction of monosaccharide
- reaction with aldehyde or ketone (hemiacetal/hemiketal product)
- linear to ring structure forms
glycosidic bond
- dehydration synthesis reaction
- join monosacc/longer sugar chains
forms di,oligo,polysaccharides - in acidic environment
central dogma of molecular biology
DNA-(transcription)->RNA-(translation)->protein (amino acid)
nucleotide vs nucleoside
nucleotide: sugar ribose+base+phosphate
nucleoside: sugar ribose+base
nitrogenous bases (5)
pyrimidine: C, T (DNA), U (RNA)
purine: A, G
define deoxy-ribo-nucleic-acid
deoxy: without oxygen on 2’ carbon of ribose
ribo: ribose sugar
nucleic acid: nucleotide
acid: acidic phosphate group
why does DNA have double helix?
- strands oriented is opposite direction
- complementary base pairs
- H bond bw bp
- VDW bw stacked bases
heterochromatin vs euchromatin
hetero: when cells not dividing (interphase), chromosones are more packed
euchro: less condensed (in prokaryotes)
denaturation, annealing, melting
denat: DNA strand seperation, w/ or w/out T chnage
annealing: upon cooling, some/all complementary strands re establish
melting: seperation above given T
DNA melting curve, DNA melting temperature
- dna absorbs more light when it denatures
- T as which slope of absorbance is steepest
result of RNA annealing
- forms double helical and complex 3D structure
- tRNA (transfer)
- rRNA (ribosome)
tRNA vs rRNA
tRNA: 3D cloverleaf created by local annealing of nucleotides
rRNA: 3D in ribosome, part of catalytic rxn to make protein (active site of ribosome)
interactions that stabilize DNA (4)
- hydrophobic effect
- H bond bw bp
- base stacking
- ionic int bw neg phosphate backbone and ions in solution
peptide bond
- between carboxyl and amino group
- condensation/dehydration synthesis
pKa and acidity
pKa incr, Ka decr, acidity decr
pH>pKa vs pH
pH>pKa (basic): fg deprot ie acts as acid
pH
buffer selection
- capacity highest when pH=pKa
- low slope regions: low pH changes
isoelectric point
pH at which the average charge of a solution containing the amino acid is neutral
secondary structure
- h bond within backbone of one strand
- alpha helix
- beta sheet (parallel vs antiparallel)