basics of biology Flashcards
4 basic biomolecules
lipids, carbohydrates, proteins, nucleic acids
How are monomers joined?
dehydration synthesis
what is the only class that isn’t made up of monomers?
lipids
hydrolysis
chemical process that splits bonds by the addition of water
what does a nucleotide contain
phosphate - sugar backbone and nitrogen base
why is dna negatively charged
phosphate groups
which nucelotide bond is stronger, why
g — c bc it has a triple bond and a – t only has a double bond
what is dna structure and why is it important
antiparallel –> allows pairing of complementary bases and formation of H bonds
what are the purines
Adenine, Guanine
what are the pyrimidines
(CUT) Cytosine, Uracil, Thymine
primary structure of protein
amino acid chain
secondary structure of protein
a - helices and b - sheets
tertiary structure of protein
polypeptides chains in space
quaternary structure of protein
multiple polypeptide chains
topoisomerase function
Keeps seperated DNA strands apart
helicase function
unravels DNA strands
primase function
makes primers on the RNA primer fragments
which direction is DNA synthesized
5’ - 3’
why is the lagging strand lagging
DNA polymerase can only add nucleotides in the 5’ to 3’ direction. As the replication fork opens, the lagging strand template is oriented in the 3’ to 5’ direction, creating a challenge for continuous synthesis. Creates okazaki fragments
DNA Ligase function
join okazaki fragments together
DNA Polymerase function
synthesizes new DNA strands, proofreads sequence
single strand binding protein function
protect against nuclease
what gets spliced in mRNA processing
introns
what is expressed from mRNA processing
EXons (EXpressed)
where does transcription happen in eukaryotes
nucleus , exits through pores
translation - initiation
large subunit binds to small subunit, initiator tRNA carrying amino acids binds to start code (AUG) on mRNA
translation - elongation
ribosome moves along mRNA in 5’ - 3’, tRNA’s bring amino acids to ribosome and peptide bonds form between amino acid, creating polypeptide chain
translation - termination
translation continues until stop codon (UAA, UAG, UGA), ribosome detaches from mRNA
telomeres purpose
consists of repetitive DNA sequences, “protective cap”, prevents loss of essential genetic info
apoptosis function
cell death
how is DNA replicated
semi-conservative model (keeps one original strand and replicated strand)
