Exam I Flashcards
physiology
fundamental understanding of function
animal
multicellular heterotroph without a cell wall
what are the two questions of physiology?
-What is the mechanism for which a function works?
-How do these mechanisms come to be?
natural selection
increase in gene frequency that increases fitness
Darwin’s Postulates (5)
- All organisms show variation
- All species produce more offspring than can survive
- Individuals with favorable traits will tend to survive and reproduce, passing favorable traits to offspring
- Result is a change toward favorable traits in the population
- Over time, this leads to organisms becoming adapted to their environment
r-selection
lots of progeny with less resources; low survivorship
k-selection
less progeny with more resources; higher survivorship
adaptive significance
why is the trait an asset? why does natural selection favor the evolution of a trait?
adaptation
physiological mechanism, long-term, not easily reversible
acclimatization
short-term adjustment to physiology from natural environment
acclimation
short-term adjustment to physiology from lab setting
central questions of physiology (3)
- How does it work?
- What is it for?
- How is it shaped?
mechanism
the components of the actual, living animals and the interactions among those components that enable the animals to perform as they do
homeostasis
organisms work to maintain a constant internal environment
negative feedback loop
effective in maintaining homeostasis
ex: blood glucose levels
positive feedback loop
creates a snowball effect
ex: expelling fetus from the uterus during childbirth
conformity
if an animal permits internal and external environments to be equal
regularity
an animal maintains internal constancy in the face of external variability
Claude Bernard observed these patterns (2):
- Atoms are constantly being exchanged in the environment
- Most cells experience a relatively constant environment (with respect to glucose concentration)
scaling
-the study of physiological and morphological traits in relation to body size
-related species of large and small size can be viewed as scaled up or scaled down versions of their type
body size
-the physiological properties of related animal species typically scale in mathematically consistent ways with their body sizes
-nonproportional, therefore allometric
bone strength
is dependent on cross-sectional surface area
bird wings +lift
increased surface area creates more lift
what was learned from the LSD on elephants experiment?
-Because they based their dosage on body weight alone, the elephant died
-LSD works in the brain, so they needed to consider both body size and body weight
a shrew expends ___% of total body energy every hour
1%
an elephant expends ___% of total body energy every ____ days
1%, 5 days
allometry
the study of the proportion of body size
the sum of anabolic and catabolic reactions
the rate at which an organism consumes energy
MO2
mL O2/hr
VO2
- mL O2/g*hr
-metabolic rate
Q
cardiac output (mL/min)
equation for cardiac output
Q=HR*SV
HR
heart rate
SV
stroke volume
annotating
determining the role of genes
what is unique about icefish blood?
-They do not produce hemoglobin; they lack heme groups
-Produce a pseudogene (alpha) and no beta
How is Antarctic water advantageous to icefish survival?
-Very cold water is highly oxygen-saturated
-The coldness plays a role in their survival because it tends to depress their metabolic needs for O2 and it tends to make O2 particularly soluble in oceanwater and their body fluids
What is the evolutionary pattern involving the deletion of globin genes?
In all icefish species, they exhibit the same deletions, meaning they were inherited from the same ancestor
role of hemoglobin in muscles
increases the rate at which O2 diffuses into the cells and sometimes acts as an internal storage unit of O2 for the cells
myoglobin
muscle hemoglobin
the loss of myoglobin in some icefish species indicates that
-the myoglobin free icefishes evolved independently more than once
-the diversion of myoglobin and hemoglobin are completely different
compared to with related red-blooded fish, ice fish…
have much larger hearts and circulate their blood at much higher levels
parsimony
Occam’s razor, the simplest answer is usually the right answer
antifreeze glycoproteins
-keeps blood from freezing
-evidence suggests that these glycoproteins likely evolved before icefish appeared
colligative properties
-examples: NaCl and glucose
-properties of solutions that depend on the number of particles in the solution but not the nature of the chemical species
non-colligative properties
-glycoproteins bind to ice crystals to prevent further growth
-the composition and property of the solvent are uniform
genomics
the study of genomes in organisms
gene family
all of the genes in a family share distinctive DNA base sequences
what three things were learned from purple sea urchin gene family analysis?
-unusual cellular communication system
-unusually elaborate immune and detoxification systems (may explain their longevity)
-repeated genes from other vertebrates suggests a common ancestor
trypsinogen
inactive protease of trypsin; found in the pancreas
transcriptomics
what genes are being upregulated/downregulated
DNA microarrays
the basis for the study of gene transcription
control group in DNA microarrays
red, indicates downregulated genes
experimental group in DNA microarrays
green, indicates upregulated genes
gene knockouts
manipulation of certain functional genes
gene knockdown
introduces an interfering RNA strand, significantly decreases expression
protostomes
-“first mouth”
-mollusks, annelids, arthropods
-most animals are protosomes
deuterostomes
-“second opening”
-echinoderms, chordates
protostomes cleavage
spiral and determinate
protostomes coelom formation
-Schizocoelous: solid masses of mesoderm split to form the coelom
protostomes fate of blastopore
mouth develops from blastopore
deuterostomes cleavage
radial and indeterminate
deuterostomes coelom formation
-enterocoelous: fold of archenteron form coelom
deuterostomes fate of blastopore
anus develops from blastopore
transport of solutes
essential for maintaining homeostasis
simple diffusion
-most straightforward form of passive solute transport
-high concentration –> low concentration
-effective for short distances, doesn’t require energy
rate of diffusion
how fast something moves from high to low concentration
Fick equation
J=D(C1-C2/x)
J
rate of diffusion
C1&C2
concentrations
X
distance between concentrations
D
diffusion factor (proportionality factor)
concentration gradient
-(C1-C2/x)
-how much the concentration changes per unit of distance
boundary layer
decreases the rate of diffusion, increases x
bulk solution
-the solution that is away from contact with a membrane
-the concentrations of positive and negative charges is always equal
-the net charge of any bulk solution is 0
electrical gradient
the difference in voltage between two sides; affects the diffusion of all charged solutes
Nerst equation
directly compares concentration gradients and electrical gradients to determine which is stronger
a typical cell membrane is ____ charged on the outside and ___ charged on the inside
positively, negatively
Cl- diffusion in active transport
-at or near electrochemical equilibrium across the cell membrane
-usually more concentrated outside the cell
Na+ diffusion in active transport
-more concentrated on the outside of the cell
-very far from electrochemical equilibrium across a cell membrane and has a great tendency to diffuse from the extracellular fluid into the cell
K+ diffusion in active transport
not at chemical equilibrium across the cell membrane
faciliatated diffusion
the spontaneous passive transport of molecules/ions across a biological membrane via specific transmembrane integral proteins
factors of facilitated diffusion
- it always occurs in the direction of electrochemical equilibrium
- solutes transported by this mechanism move across membranes much faster than they could if they did not associate it with transporter proteins
- the mechanism requires solutes to bind reversibly with binding sites on transporter proteins
facilitated diffusion example
-glucose transport from blood –> cells
-insulin controls/activates facilitated diffusion
active transport
-have the ability to carry material in the direction opposing equilibrium
-ATP is required
transporter/carrier
membrane protein that mediates active or passive transport across the membrane by binding noncovalently and reversibly with solute
ligands
solutes that bind noncovalently and reversibly with a transporter protein
Na+-K+ pump
-transports three Na+ ions out of the cell and two K+ ions in
-helps to create a difference in charge across the cell membrane
-found in the basolateral membrane of all epithelial cells
Na+-K+-ATPase
an enzyme that catalyzes the hydrolysis of ATP as well as serving as a transporter
Na+-K+-ATPase pumping cycle step 1
- three intracellular Na+ binding sites have a high affinity for Na+ when the ATPase is in its dephosphorylated state
Na+-K+-ATPase pumping cycle step 2
hydrolysis of ATP phosphorylates the molecule, decreasing the Na+ affinity of the intracellular binding sites. The released Na+ ions disappear into an “occluded” state inside the protein. Two extracellular K+ binding sites develop high K+ binding affinity
Na+-K+-ATPase pumping cycle step 3
the phosphorylated molecule releases Na+ into the extracellular fluid. Two K+ bind to the K+ binding sites
Na+-K+-ATPase pumping cycle step 4
Dephosphorylation causes the K+ to be released into an “occluded” (out of communication) state inside the protein
Na+-K+-ATPase pumping cycle step 5
K+ is released inside the cell. The Na+-binding sites regain high affinity for Na+
primary active transport
-active transport that draws energy immediately from the hydrolysis of ATP
-transporter protein=ATPase
secondary active transport
-draws energy from an electrochemical gradient
-ATP is required, but is not the direct source of energy
cotransporter
-protein that moves 2 solutes in one direction
how do hummingbirds have a diet that consists of nearly all glucose?
they can handle these high levels of glucose because they have an extremely high cotransporter activity
epithelial cell glucose transport mechanism
-glucose enters the epithelial cell across the apical membrane by secondary active transport
-leaves the basolateral membrane by facilitated diffusion mediated by a glucose-transporter protein
how do freshwater fishes replenish Na+ and Cl- ions?
-Na+ pumping mechanism secretes H+ into the water for Na+
-Cl- pumping mechanism secretes HCO3- in exchange for Cl-
-employ active waste ions to keep the active uptake mechanisms of Na+ and Cl-
a lack of compounds is
undernourished
a lack of nutrients is
malnourished
essential nutrients
necessary for enzyme production
proteins
~50% of all organic matter in animals
-used in AA production, antibodies, venom
nutrition
the study of chemical compounds that compose the bodies of animals and how they are able to synthesize those chemical compounds
standard amino acids
22 in total, animals can produce them on their own
essential amino acids
animal cannot produce on their own
lipids
membrane composition, energy storage, waterproofing, steroids, insulation (padding)
saturated fatty acid
all bonds between carbons are single bonds
unsaturated fatty acid
one or more bonds between carbon atoms are double
carbohydrates
structural support, energy storage (glycogen), transfer of energy (glucose)
GULO
a gene that catalyzes the last step in the ascorbic acid (Vitamin C) biosynthetic pathway
GULOP
-a pseudogene with a frameshift mutation at codon 346
-vitamin c deficiency was not a problem, so the GULO gene was lost
-the GULOP gene is homologous to the GULO gene
-this is why we can get scurvy
feeding: behavior
-animals change their behavior to fulfill a need
-ex: spiders and specific flies
feeding: structural
-anatomical adaptation
-ex: bird bills
snail radula
tongue-like apparatus, small grooves on the surface that are made of chitin
cone snail
-modified radula, harpoon shape
-inject conotoxin into victims
what does conotoxin do?
it inhibits the binding of acetylcholine, replacing it with alpha-conotoxin, and paralyzing the victim
zooxanthelle
-what gives coral color, resides in the gastrodermis
-Coral bleaching is a result of lack of zooxanthelle
riftia
-hydrothermal vent worms
-contains sulfur oxidizing bacteria
trophosome
-sulfur-oxidizing bacteria (food source)
-participates in the redox reaction: SO4—->H2S
heterotrophic microbes
source is large C molecules, gut microbiome, anaerobic
probiotics
living bacteria that reside in the gut
Artiodactyla
-ruminants, fore-gut fermenters (esophagus and stomach)
-6 families
-even toed
Perissodactyla
-odd-toed
-hind-gut fermenters
-3 families
rumen
-very efficient; microbes colonize the materials and ferment
-anaerobic
-synthesize amino acids
-nitrogenous waste can be used to break down materials further
reticulum
honeycomb shape, removes H2O
abomasum
closely resembles the ‘true stomach’
hindgut fermenters
-less efficient
-break down cellulose in either the cecum or the colon
-they don’t break down a lot of vitamins/AA, so they have to rely more on consumption
day pellets vs. soft pellets
-cellulose+non digestible materials
-derives from cecum; reingested to get nutrients
termite digestion
-diet is entirely comprised of cellulose
-flagellates, which make up about 1/3 of their body weight, produce cellulase
intraluminal enzymes
occurs inside the gut, mixes with chyme, inactive form/enzyme (zymogen)
mucous cells secrete
mucous
chief cells secrete
pepsinogen
parietal cells secrete
HCl
intracellular digestion
food particles are taken into specialized cells prior to digestion, digestion occurs within the cells
extracellular digestion
digestion in an extracellular body cavity, such as the lumen of the stomach or the small intestine
gut length in carnivores
shorter because meat is easier to break down
gut length in herbivores
longer because cellulose is difficult to break down
nutritional genomes
alteration of genomes/enzymes dependent on diet
1st law of thermodynamics
conservation of energy, efficiency
2nd law of thermodynamics
law of entropy; measure of disorder; increased entropy=increased energy
energy
the capacity to perform physical work
physical work
decrease in entropy, increase in order
what are the forms of high grade energy?
chemical, electrical and mechanical
what are the forms of kinetic energy?
mechanical and heat
what is considered low grade energy?
heat energy
efficiency of energy transformation equation
output (usable) energy/ input of energy
energy is used for
- biosynthesis
- maintenance
- external work
metabolic rate
the rate at which an organism consumes energy, chemical energy being converted to work
*one of the most important physiological indicators
calorimetry
-the most direct way to measure MR
-the amount of water needed to melt 1 gram of water
respiratory quotient equation
CO2 produced/O2 consumed
closed respirometry
-rate of movement=rate of O2 consumption
-lack of CO2 affects results/metabolism
-only works with small animals
open respirometry
-airflow in and out
-more precise data
-more realistic environment
-second to second readings
conductance
the inverse of insulation, how easily heat is lost to the environment
endotherm
generates own body heat
ectotherm
body heat is generated from external environment
specific dynamic action (SDA)
-metabolic rate can change as a result of ingesting a meal
-~25% of protein meal can be lost to SDA; this could be an expense of nitrogenous waste
-diet-induced thermogenesis (meat sweats lol)
basal metabolic rate (BMR)
-environmental factors to determine the lowest metabolic rate; resting rate
-endotherms
standard metabolic rate (SMR)
-at a specified temperature
-ectotherms
VO2 max
-the highest metabolic rate
-can be around 10x the amount of BMR
