lots and lots of chemical digestion occurs in the small intestine
chemical messenger secreted by specialized cells, they act on target cells (as it travels through your body) and bind to specific receptor and activate signal-transduction pathway
appetite supressor (fat cells secrete this)
absorbes water and excretes solid wastes, it also contains bacteria that synthesize vitamins that we need.
eat plants, but don't have the enzymes to digest cellulose
why do herbivores have a longer small intestine than carnivores?
because plants are harder to digest than meat
chamber that contains microbes that can digest cellulose
crushin grinding thing for really hard to digest stuff like insects
used for storage (in just birds?) of food and it can come out of crop when they need it
all respiratory surfaces must be . .
thin (with large SA), moist (gases dissolved in water) and composed of living cells
most surfaces are . . .
richly supplied with blood vessels (EXCEPT INSECTS)
what are the challenges faced by aquatic animals?
there's less O2 present in water than in air, O diffuses slower through water than air and water is denser than air (so you need more muscle)
what are challenges faced by land animals?
desiccation (drying out-your respiratory system HAS to be moist)
emphibeans and eels are an exception to the entire outer skin ruel, they can exchange gas through their skin
the respiratory system has to have a high surface area so . . .
the respiratory organ/system is extensively folded or branched
hole in animals body that air goes into
spiracle --> trachea --> tracheoles (in insects)
the respiratory surface for most aquatic animals
protective covering for gills
any mechanism that increases contact between respiratory medium and respiratory surface
how do fish ventilate gills?
they seim with mouth open, close their mouth/open operculum, and throat muscles (squeeze and push more H2O past their gills)
blood always HAS TO flow in direction opposite the movement of water psat the gills
we are endotherms
absorb external heat rather than generating their own, and low(er) O2 needs
use heat generated by metabolism to maintain warm body temp, VERY high O2 needs, energetically costly
where does gas exchange occur in us?
tip of broncheoles
trachea --> lung --> bronchus --> bronchioles
gas exchange takes place across these
why are birds more efficient at exchanging O than us?
they have a 1 way air flow i/o 2 (parabronchi i/o alveoli), and air flow is crosscurrent with blood flow (
what are the 3 main components of blood?
plasma, white blood cells, red blood cells
how much of the blood does plasma make up?
carries some O2, CO2, waste and other soluble stuff
white blood cells
red blood cells
carry O2 and contain RESPIRATORY PIGMENTS
increase O2 carrying capacity of blood
our respiratory pigment
iron helps bind up O2
they wave up and down, pushing dirt back up, smoking destroys them
cillia get paralyzed in whooping cough
3 kinds of vessels in closed circulatory systems
arteries, veins, cappillaries
carry blood AWAY from heart
return blood to heart
convey blood between arteries and veins within each organ
chamber that accepts the blood (in 2-chambered only?)
know reasons that flow of blood slows down
why its slow moving
the blood leaves the heart moving fairly quickly and then it gets to the first capillary bed thats really branched so it slows down, then it gets out and then it goes through 2 more so it slows down even more??????
what is a problem with double circulation?
there's a mixing of O-rich and O-poor blood that gets delivered to tissues, so its not as oxygenated as it could be
reptiles have a partially divided ventricle **
no blood pressure issues with 2-chambered heart
has a speration of oxygenated and deoxygenated blood
it takes A LOT more energy to be an endotherm
endotherms use 10x more energy as same size ectotherms
normal funcioning genes
both alleles are present in the phenotype
how many alleles give us our blood type?
sex-linked = x-linked
why do sex-linked disorders affect mostly men?
because they're hemizygous, and if an x is defective they don't have another one to compensate for it
physical traits of an organism determined by genetic makeup. physical traits
altered version of a gene
genetic makeup of an organism (what allele is present)
cascade of interactions between intracellular signaling protiens (1 protein gets activated and then activates the one next to it and so on)
cancer causing proto-oncogenes
genes that encode signals, receptors, signaling molecules, control proteins
what are some ways for P-O to become O's?
point mutations and gene amplification
what are some sources of point mutations?
mistakes in DNA rep, exposure to mutagens, viruses injecting their DNA into a gene
Her2 is linked to what type of cancer?
type of P-O. signal binds to receptor signaling transduction pathway resulting in the turning on of genes that stimulate division and inhibit cells from dying
what can be used to shut down excess Her2?
it recognizes and binds to specific molecules, an antibody was made that can bind to Her2 receptors
proteins that inhibit cell division
what can happen to tumor supressors?
they can get mutated and override checkpointsand then invade other parts of the body
helps cells decide weather to repair damaged DNA or commit cell suicide
what can HPV do to P53?
it can integrate into the host genome and destroy the p53
normally encodes protein that helps repair damaged DNA at G2
what happens when BRCA2 is damaged?
damaged DNA is allowed to pass through mitosis leading to breast and ovarian cancers
enzyme that permits entire telomere to be replicated so chromosomes don't shorten (when its turned on it does this)
cells enter bloodstream or surrounding body fluids
used in chemotherapy, prevents microtubeales from shortening
what are some solutions to living at high altitudes?
large heart and lungs, many RBCs, RBCs have high hemoglobin, hemoglobin has high affinity for O2
O2 binding protein, intracellular O2 reservoir
what prevents blood from going backwards in our veins?
they have one way valves in them
why do we need iron?
for O2 to bind
individuals with this are sorta resistent to malaria, but they have the sickle cell allele and it gets passed on and thats why sickle cell is more common in africans
sickle cell is autosomal recesive
all the genetic material contained in an organism
since all of our cells contain our entire genome the difference b/w them isn't genetic but . . .
any process that alters gene activity . . . w/o changing DNA sequence . . . leads to modifications that can be transmitted to daughter cells
epigenetic modifications include addition of molecules like methyl groups (CH3)
how can you recognize ATP?
it has 3 phosphates
what happens when you remove the phosphates from ATP?