Bio Test 1 Takeaways Flashcards
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DNA helicase
unzips the wound DNA double helix at replication fork
single-strand binding proteins
attach to each strand of uncoiled DNA to keep them separated
Topisomerase (DNA gyrase)
creates small nicks within DNA to relieve tension ahead of replication fork
primase
places RNA primer at origin of replication
DNA polymerase
extends the complemtary strand in 5’ –> 3’ direction
DNA sliding clamp
holds DNA polymerase to the template strand
DNA ligase
“glues” together DNA fragments on lagging strand by catalyzing the formation of phosphodiester bonds
telomerase
extends telomers at the ends of eukaryotic chromosomes to prevent DNA from losing information
exploitation competition
indirect competition and occurs when a shared resource like territory, prey, or food is depleted
gastrin
- stimulates parietal cells to release gastric juice
- stimulates chief cells to release gastric lipase and pepsinogen
fixed action pattern
inherited behavioral sequence that continues to completion in response to specific stimulus
internal fertilization
require fewer gametes because the male directly deposits sperm into female’s body
microfilaments (actin)
work with myosin to perform cleavage furrow during cell division
how do proto-oncogenes become cancerous?
one-hit-gain-of-function mutation
how to tumor-supressor genes become cancerous?
via two-hit-loss-of-function mutation
