final terms Flashcards
yeast
mating types are a and alpha, a will send out a signal and alpha has a specific receptor that will get the signal so they can mate
ligand
chemical messenger that is produced and released by one cell and then binds to a receptor for the signal to be interpreted
cell junctions
allows adjacent cells to be directly connected and pass signaling molecules
cell-cell recognition
one cell wants to pass on a message and it is beside another cell that it can interact with to send the message
paracrine signaling
no direct physical contact between cells, cells must be close but they do not have to be in direct contact
synaptic signaling
neurons release neurotransmitters that diffuse across a synapse
endocrine signaling
hormones, used mostly in animals
3 stages of cell signaling
- reception, message first reaches the receptor 2. transduction, cell has to alter the language of the message to it is easier to understand 3. response, cell makes a response out of the signal
transmembrane receptors
ligands bind to transmembrane cell surface receptor proteins (GPCR and RTK)
g protein coupled receptors GPCR
abnormal receptors are associated with disease. GDP makes it inactive, GTP makes it active
g-protein
needs to bind to GPCR to make it active. GDP inactive, GTP active
Receptor tyrosine kinases
membrane receptors that attach phosphates to tyrosines
binomial nomenclature
Carolus Linnaeus. First is genus then species within the genus
monophyletic groups
includes common ancestor and all species after it
paraphyletic
common ancestor and some of the branched species but not all
polyphyletic
does not include the common ancestor. only some of its descendant species
ancestral characters
character of a species that it shares with one or more of its ancestors
shared derived characters
character that is only unique to that specific species. is not shared with any other species or ancestor
endosymbiosis
thought that early mitochondria and protists were just prokaryotes that were living in larger host cells
Pangaea
continental drift causing all continents to come together. happened 3 times. reduced shallow water habitat, became colder and drier in the inland, changes ocean circulation leading to global warming
adaptive radiation
species branch off from common ancestor early on to adapt to new environments
continental drift
earths continents shift around via tectonic plates. happens because of underlying hot mantle, causes islands, mountains and earthquakes
cambrian explosion
sudden appearance of fossils that resemble modern phyla during the cambrian period (535-525 million years ago)
stromatolites
rock structures with bacteria in between the different layers first evidence of prokaryotes
oxygen revolution
because bacteria was letting off so much oxygen it started taking up too much space, prokaryotes started to die off because they have less fitness in oxygen rich environments. 2.1 to 2.7 billion years ago
single celled eukaryotes
approx 2.1 billion years ago. endosymbionts that live within a larger host cell
multicellular eukaryotes
1.5 billion years ago. shows beginning of evolution
colonization of land
fungi, animals and plants begin to colonize the land. 500 million years ago
consequences of pangaea
during formation it made inland colder and drier, changed ocean pathways which lead to global warming, less shallow water habitats. during separation it made allopatric speciation happen
permian extinction
96% of all species went extinct. happened because of volcanism which lead to less oceanic oxygen which lead to global warming
cretaceous mass extinction
because of the meteor that hit earth, 50% of marine animas and many other plants and animals went extinct
consequence of mass extinction
paves the way for adaptive radiation, alters the ecological niches and communities that are available
biological species concept
group that has potential to interbreed and produce viable offspring
morphological species concept
defines a species on its structural features, emphasizes unity
ecological species concept
defines a species on where its habitat is. emphasizes disruptive selection
prezygotic barriers
barriers that prevent two species from mating or fertilization to complete
habitat isolation
two species do not come into contact often because they don’t live near each other
gametic isolation
the sperm of one species does not work to fertilize the egg of another species
temporal isolation
two species mate at different times (in the day or in the year) so they never mate even if they might come into contact
behavioral isolation
mating rituals that are species specific do not mix with other species.
mechanical isolation
the physical/morphological differences of the two species do not allow mating
postzygotic barriers
telling if the offspring is fertile/viable
allopatric speciation
“different country” species that become separated physically somehow so they evolve in different ways
sympatric speciation
“same country” species live around the same area but do not mate for some other reason (some type of isolation probably)
reinforcement hybrid
hybrid does cannot reproduce as well as its parents, reinforcing the prezygotic barriers
stabilization hybrid
hybrid reproduces better than its parents. prezygotic barriers will decrease. results in 3 different species (both parents and their hybrid child who can continue to make hybrid children)
fusion hybrid
hybrid reproduces just as well as its parents (not better or worse) creates a fusion between its parents (a new species)
punctuated model
species change most as they branch from a parent then less overtime
gradual model
species change from one another gradually over time
HER2 receptor
overly active in breast cancer. can act without the ligand
ligand gated ion channel
receptor acts as a gate when it changes shape. will open up for specific ions (na/Ca) through a channel
intracellular receptors
found in cytosol are hydrophobic and pass through the membrane to activate a receptor
second messengers
initiates by GPCRs and RTKs small nonprotein ions that diffuse within a cell. Ex. cyclic amp (cAMP)
first receptors
ligands
cholera
produces a toxin that modifies the g protein so it produces excess amounts of salt and water will eventually run dry
PIP2
lipid that forms in association with the membrane. is the substrate to phospholipase
fluid mosaic model
the cell membrane is a fluid structure with a “mosaic” of proteins
testing the fluid membrane theory
using fluorescent green stain to stain the membrane, then making a hole within the membrane to see if the green stain begins to cover up that hole FRAP
cholesterol
fluid that allows the membrane to be more fluid at warmer temperatures and less fluid at colder temperatures
integral proteins
penetrate the hydrophobic core and get embedded in the membrane. Become transmembrane proteins f they stay on the membrane
aquaporins
allow water passage through the membrane through a pressure gradient (pressure builds up outside the cell then is released only down this specific passage)
passive transport
does not need energy to happen, pressure moves down gradient from high to low concentration
amplification
stimulation of a signal at transduction leads to amplification of signal. happens through enzyme cascades
specifity
different receptors allow different responses. different types of protein are produced by different types of cells
termination
signal is terminated is the ligand concentration falls
aptopsis
programmed cell death. occurs to recycle cells or create the proper shape. happens through the inactivation of a specific protein to allow different enzymes carry out killing the cell
ced-9
protein that is in a cell that does not allow aptopsis. when inactivated it automatically activates ced-3 and ced-4 so cell death can occur
capases
main proteases that actually kill the cell
alpha helix
coil held by hydrogen bonds on every fourth amino acid. part of secondary structure
B pleated sheets
two polypeptide chains held together by hydrogen bonds. part of secondary structure
disulfide bridges
when coiling a protein and two cystines come close together their S molecules can bond together
hydrophobic interaction
when some molecules are hydrophobic, they travel to the center of the protein and hydrophilic molecules can be on the outside. Part of the secondary structure
X ray crystallography
diffracting x ray beams off a protein to figure out the 3D structure
endomembrane system
nuclear envelope, ER,, Golgi apparatus, lysosomes, vacuoles and plasma membrane
endoplasmic reticulum
continuous with nuclear envelope and makes up more than half of the membrane
smooth er
detoxifies drugs, synthesizes lipids, stores calcium ions, does not have ribosomes
rough er
has ribosomes, synthesizes glycoproteins, is the “membrane factory” makes parts of the membrane
rough er stress response
happens because there is a clog of proteins that are mis or unfolded
short term rough er stress response
create more chaperone proteins to help keep the proteins being made moving along
long term rough er stress response
killing itself
golgi apparatus
flat membrane sacs that modifies products of the er and is the sorting factory. sorts and packs things that come from the rough er
lysosomes
digestive compartments with hydrolytic enzymes to digest macromolecules
vacuoles
derived from er and golgi apparatus to perform other things
mitochondria
site of cellular respiration, a metabolic process to generate atp with oxygen
darwins definition of evolution
descent with modification
Theodosius Dobzhansky
nothing makes sense except in light of evolution
largest to smallest category grouping
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
emergent properties
emergent from arrangement or interactions of parts within a system. not unique to life
smallest protein
FMRFamide (4 amino acids long)
largest protein
Titin protein (38000 amino acids)
first law of thermodynamics
energy in the universe will remain constant but energy can only be converted, not created
isotonic
nothing moves in or out of the cell, cell will remain the same
hypertonic
cell shrivels because water tries to go from inside to outside the cell
hypotonic
cell will burst because concentration was higher inside the cell and too much water went in the cell and caused it to burst
main steps of translation
- initiation, begins translation. 2. elongation, adds on amino acid pairs 3. termination, finds stop codon and is done translating
anticodon
complementary tRNA codons to the mRNA codons
how many binding sites does trna have and what are they called
3 sites, A, P and E site
A site in ribosomes
holds trna that carries next amino acid onto the chain
P site in ribosomes
holds trna that has growing polypeptide chain
E site in ribosomes
exit site where discharges trnas leave the ribosome
what enzymes make sure the right amino acids are attached to the right trnas
aminoacyl trna synthases there are 20 different types in humans, one for each amino acid.
wobble base pairings
because there are 61 codons and most proteins only need about 40, there can be a time where there is an unconventional base pairing. when the antiparallel base pairing the first two bases match up fine but the third one isnt normal, it is enough for the first two to be normal and the third one to be unconventional for the base pairing to still work
transition mutations
the mutation just switched out a amino acid of the same type (pyramidine for pyramidine or purine for purine)
transversion mutation
mutation switches out amino acid of different type (puring for pyramidine and vice versa)
recombinant dna
hybrid dna molecule from joining of two or more dna molecules
restriction enzyme
endonucleases. cuts dna at very specific sequences. after the cut the fragment that is left the ends are called sticky ends, and as long as you use the same endonuclease, you can stick the ends of two different molecules together
dna ligase
joins the sticky ends together
how do you know if the plasmid has actually taken up the vector
using a amicillin to grow the bacteria and also injecting the plasmids with ampicilin resistant, if the cell dies, the plasmid did not actually take up the vector, but if it lives, you can tell that the plasmid has taken up the vector
polymerase chain reaction (PCR) test
- dna is heated to release double helix 2. primer is added and binds to specific parts of dna that is to be amplified, solution is cooled 3. heat protectant enzyme is added and solution is heated again to hotter than before 4. dna is amplified many times until you can tell the answer
