M1- Animal Phys

DORC

D ynamic

• allostasis vs homeostasis

• allostasis= ur body reacting to external environment in normal way

• homeostasis= state of balance, maintaining relatively constant environment

O rganized

• compartments, movements of fluids, nutrients, hormones are predictable

R equire energy

• exogenous material necessary

C hange

• changes over their lifetime

what makes an animal an animal?

• multicellularity

• heterotrophic (need to bring food in, cant synthesize own)

• internal digestion

• movements (some extreme)

tissue layers

• endoderm

  • digestive + respiratory tracts, pancreas, liver

• mesoderm

  • organs, blood, muscle + bone

  • only in triploblastic organisms

• ectoderm

  • nervous system, eyes, skin

circulatory system properties

• muscular pump (heart)

• conduits/network

• fluid that transports respiratory gases +/or hormones + nutrients

functions of circulatory systems

• O2 + CO2 transport

• nutrient + waste pdt transport

• disease protection + healing

• hormone delivery

• body temp regulation

• some might not have bc of high SA:V ratio

  • if v small + thin walls they can just exchange fluid w/ the outside environment

open circulatory system

• open to body cavity of animal (hemoseal)

• has no arteries

• has more blood @ low pressure

• requires less energy for distributing blood

closed circulatory system

• fluid kept w/in conduits/pipes of circulatory system, bulk of fluids maintained in circuits

• has arteries (endothelial cells)

• carries blood @ high pressure + delivers blood quickly (elastic- can stretch + rebound)

• movement, digestion, + waste removal is quick

incomplete circulatory system

• in between open + closed systems

  • has properties of both

• arteries present (lack endothelial cells + no muscle surrounding them)

• no smooth muscle/endothelial lining

• arteries contract + control fluid through valves

fluids in a closed circulatory system

• intracellular fluid- 40%

  • in cytosol of our cells

• extracellular fluid- 60%

  • blood, lymphatic fluid

  • interstitial

  • intravascular

  • transcellular

lymphovascular (intravascular fluid?)

• interstitial spaces → fluid from blood

• surrounds our arteries + veins, type of conduit system

• accessory route for fluids in our bodies

• larges pores- fenestrations- allow for fluid + macromolecules to be released

• drains from all tissues

• lymph nodes

burst activity

• able to release lots of energy in a very short period of time

sustained energy

• lots of energy being dissipated over a really long period of time

  • ATP needed for this

rigor mortis

• “stiff death”

• muscles become stiff b/c we need energy (ATP) to contract + extend them

• when body no longer generating any more ATP to relax muscles so body remains stiff

ATP

• adenosine triphosphate

• source of energy for the cell

• 3 things to remember:

1. each cell makes its own ATP

2. ATP is not stored in any appreciable amount (always need to make it)

3. rate of ATP production dependent on individual cell (not all cells have same mechanism for generating ATP)

metabolism=

catabolism/anabolism

• how much energy you are using

catabolism

= aerobic + anaerobic

• converting chemical energy into usable energy like ATP, maintenance, physiological work

• aerobic → CO2 + H2O (2 main byproducts)

  • glycolysis

  • kreb’s cycle

  • electron transport chain

  • oxidative phosphorylation (loads of ATP generated)

anabolism

• building up tissue, tissue growth + mineralization of bone, tissue repair (biosynthesis)

glycolysis

• happens in cytosol of cell

• 1 molecule glucose → 2x pyruvic acid

• 2 molecules NAD reduced (redox rxn)

• 2 ATP used, 4 formed

  • net= 2 ATP (+ 2NADH2)

• 6 enzymes involved:

  • hexokinase

    • glucose (6C)→ glucose-6-phosphate (6C)

    • adds phosphate groups

    • irreversible

    • uses ATP

  • phosphofructokinase (PFK)

    • fructose-6-phosphate (6C) → fructose-1,6-diphosphate (6C)

    • rate limiting enzyme (relies on amt of substrate)

    • requires ATP

  • glyceraldehyde-3-phosphate dehydrogenase

    • x2 glyceraldehyde-3-phosphate (3C) → x2 1,3-diphosphoglyceric acid (3C)

    • helps important redox rxn: 2 NAD+ → 2 NADH2

      • NAD+ gains e- (gets reduced)

      • G3P loses e- (is oxidized)

  • phosphoglycerate kinase

    • x2 1,3-diphosphoglyceric acid (3C) → x2 3-phosphoglyceric acid (3C)

    • 2 ATP generated

      • adds phosphate group to ADP

  • enolase

    • x2 2-phosphoglyceric acid (3C) → x2 phosphoenolpyruvic acid (3C)

    • dehydration rxn, loss of H2O x2 (bc 2 molecules go through it)

  • pyruvate kinase

    • x2 phosphoenolpyruvic acid (3C) → x2 pyruvic acid (3C)

    • 2 ATP generated

      • adds phosphate group to ADP

kreb’s cycle (citric acid cycle, TCA)

• happens in mitochondrial matrix

• carboxylation reactions

  • how many CO2? → 6CO2 (3/pyruvate)

  • intermediates used to make fat + generate carbohydrates

    • b/c not closed system (open) so can be used in other pathways

• 5e- acceptors/pyruvate/cycle x2 = 10e- acceptors → go into ETC + oxidative phosphorylation

• 6CO2 released (3 per pyruvate)

• 8NADH2 + 2FADH2 (for each glucose molecule)

• net= 2 ATP

** total from glycolysis + kreb’s cycle= 4 ATP **

(no O2 needed yet)

electron transport chain

• happens in mitochondrial inner membrane

• membrane spanning proteins remove e- from NADH2 + FADH2 through them to O2 (the final e- acceptor)

  • series of handoffs of e- along inner mitochondrial membrane

FINISH!!!- need to know complexes/order of operations?????????

• malate-aspartate shuttle

• glycerol-phosphate shuttle

• 0.8 L of water generated by removing e- form cells (water is produced)

• O2 = final e- acceptor

• coupled w/ oxidative phosphorylation

ETC + oxidative phosphorylation

• ATP synthase pumps H+ back into cell + uses that energy to convert ADP → ATP

  • membrane spanning protein, couples P with ADP to form ATP)

• ATP producing stage

• net yield= 25 ATP

oxidative phosphorylation efficiency

• P/O ratio (phosphate/oxygen) = # ATP molecules

• as 10 H+ (per pair of e-) combine with 1 O2 molecule → 2.3 ATP produced

  • (highest efficiency per NAD; 2 ATP per FAD)

• graded P/O: min 0 → 2.3 ATP max

  • . (uncoupled → tightly coupled)

• net yield: 25 ATP

• total yield (glycolysis → oxidative phosphorylation): 29 ATP

brown adipose (“fat”)

• transfer chemical energy (~60-70% into ATP, rest lost as heat) + lose it to heat (no ATP made)

  • lacks ATP synthase, instead uses uncoupling protein 1

    • allows H+ to leak back into matrix which generates heat

• interscapular

• paravertebral

• pararenal

• cervical spine

• supraclavicular

uncoupling protein 1 (UCP1)

• transmembrane protein in mitochondrial matrix present in brown adipose cells

• non-shivering thermogenesis

• no energy is captured as ATP, only as heat

  • leakage in ions across the inner mitochondrial membrane (through this protein)

• small mammals in cold areas, babies

catabolic end products

• CO2 + H2O → exhaled + voided

• assuming 60-70% efficiency is captured as chemical bond ATP

reactive oxygen species (ROS)

• aging, contributes to muscle fatigue

• oxidative stress

  • can take antioxidants to help reduce?

• short lived, product of aerobic metabolism, can damage cells along etc, but our cells have ways to make these less reactive in our bodies

what happens if we do not have O2?

• impaired ATP synthesis- FADH + NADH can’t get properly recycled?

• redox imbalance- transferring e- but have no where to go bc O2 is not present to be final e- acceptor

anaerobic glycolysis

• principle anaerobic catabolic pathway of vertebrates

• 1 pyruvic acid → 1 molecule lactic acid

• no ATP generated w/ lactic acid, creating intermediate so that glycolysis can continue

  • if lactic acid accumulates- damages our muscle cells/tissue so need to get rid of it (shuttled to liver)

main way lactic acid metabolized when O2 is available

• lactic acid can be converted back to pyruvic acid when O2 is present

what do we do w/o oxygen for short period of time?

• anaerobic glycolysis

• fuel: pyruvic acid → lactic acid

• lactate dehydrogenase (LDH)

• net yield: 2 ATP

  • but now have lactic acid….

cori cycle

• lactic acid needs to get converted back to pyruvate to shuttle to liver where there is a lot of lactate dehydrogenase

lactic acid metabolism

• lactic acid is a dead end so convert back to → pyruvic acid

• O2 is necessary for 2 pathways:

  • gluconeogenesis (-6 ATP)

  • krebs/etc (27 ATP)

• as animals, we need both aerobic + anaerobic pathways

rate of ATP production is dynamic

• it changes:

  • steady state (aerobic?)

    • production + use is balanced

    • raw materials used + replenished in balance

    • byproducts made + destroyed

    • no disruption in cell function

  • non-steady state (anaerobic?)

    • self-limiting/self-terminating (can’t go on forever, shuts off at some point)

    • 3 mechanisms: (for getting ATP w/o O2)

      • anaerobic glycolysis

      • phosphagen productions

      • myoglobin

phosphagens

• mechanism for ATP production without O2

• phosphagens (skeletal muscle) + enzymes (vertebrates: creatine phosphate, invertebrates: arginine phosphate)

• shifting rxn → phosphagen or ATP (reversible rxn if too much ATP)

  • creatine phosphate + ADP ←→ creatine + ATP

  • , creatine kinase

• all animals w/ muscles (mesoderm) have some form of phosphagen to quickly generate ATP

myoglobin

• mechanism for ATP production w/o O2

• how we store O2 in our muscles

• non-steady state b/c we only store so much of this in our muscles

• aerobic catabolism

  • steady state

  • very large yield ATP

  • slow

  • moderate peak rate ATP production

• anaerobic glycolysis

  • nonsteady state

  • moderate yield ATP

  • fast

  • high peak rate ATP production

  • slow rate of return to full potential after use

• phosphagen use

  • nonsteady state

  • small yield ATP

  • fast

  • v high peak rate ATP production

  • fast rate of return to full potential after use

• myoglobin

  • nonsteady state

  • small yield ATP

  • fast

  • high peak rate ATP production

  • fast rate of return to full potential after use

reinitialization

• how rapidly can each mechanism be restored (nonsteady state)

• phosphagen, O2 store, anaerobic glycolysis

• anaerobic glycolysis takes the longest to reinitialize

• endotherms will do so quicker than ectotherms

pros	cons
ATP when O2 unavailable	carbs only
supplement accelerate rapidly + reach exceptionally high rate of ATP production	yield 2 ATP lactic acid

uses for anaerobic metabolism

• high capacity

• eutrophication- organism might be in environment that is hypoxic (lower O2)

• secondary evolution to aquatic lifestyle

• other uses of anaerobic pathway:

  • anoxia (w/o O2) + hypoxia (low O2)

  • metabolic depression

    • reduces rate at which animals need ATP

    • brain really need O2

• 100m dash use phosphagens

• 200m use anaerobic + aerobic + phosphagens

• 1500m use aerobic + anaerobic glycolysis

• understand the base idea→ longer you are running, the more likely you rely on the steady state mechanisms (aerobic)

• “with increasing duration, ATP production shifts from being principally anaerobic (based on phosphagen and anaerobic glycolysis) to being chiefly aerobic."

preserving the brain during dives

• brain needs O2

• resident neuroglobins

  • like myoglobins in muscle cells, but in brain, hold deposits of O2

  • marine mammals have lots of these in brain so when under water for long periods, their brain still gets O2

• some turtles can tolerate brain anoxia by employing metabolic depression of their brain

general muscle types

• slow oxidative (SO)

  • aerobic catabolism

  • mitochondrial density high (oxidative)

  • develop tension slowly

  • rich in myoglobin (gives them red color)

  • resistant to fatigue (b/c develops tension slow)

• fast glycolytic (FG)

  • anaerobic catabolism (anaerobic glycolysis, myoglobins, phosphagens)

  • glucose (primary substrate this muscle fiber relies on)

  • high power output

  • fatigue quickly (^ tradeoff), non-steady state

7 functions of muscle in animals

1. stabilize/control

2. movement, motion

3. thermoregulation, creating heat

4. controlling passage of materials (digestion)

5. acting on viscera (general organ systems + surrounding tissue)

6. producing noise

7. producing electricity

. 1 2 3 4

• 4 produces the most force because it has the biggest cross sectional area of muscle

• 3 contracts the largest distance, the longer the muscle the longer distance it can contract (muscles contract ~1/3 of its length)

muscle cells

• muscle cells (muscle fibers)- bundled into tubes (myofibrils)

• myofibrils are bundled tg and surrounded by mitochondria + sarcoplasmic reticulum

  • ^ releases Ca2+ into myofibrils, allows them to contract

• plasma membrane = sarcolemma (fully surrounds all myofibrils)

• in some cells, sarcoplasmic reticulum less dense, in others more dense

  • differs in what type of muscle

force production (high): short bursts- muscle fiber comp

• high myofibrils

• low mitochondria

• low sarcoplasmic reticulum/sarcolemma

force production (low): longer activity- muscle fiber comp

• low myofibrils

• high mitochondria (keeps muscle going for longer time)

• low sarcoplasmic reticulum/sarcolemma

muscle fiber comp for v fast movements

• v fast cyclic movements: rattlesnake tail shaker muscles + hummingbird wings

  • low for production- longer activity

• low muscle fiber

• high mt- enhanced (has double inner membrane)

• high sarcoplasmic reticulum- enhanced

vertebrate capacity for storage of potential energy

• we store energy in our tendons

  • if town takes a while to heal b/c small blood supply

• good for burst + cyclic movements

  • vertebrates limited in speed which energy transfer can happen

limitations on fastest vertebrate movements

• rattlesnake tail shaker muscles- muscle contractile speed

• hummingbird wings- animal size (smaller animal=faster movements)

ultrafast movement

• power amplification

  • power= work/time

  • stored potential energy w/ a quick release

• duration, speed/rate/frequency, acceleration

defining ultrafast movements

• duration= how long the movement lasts

• speed/rate/frequency= measure of movement/time

• acceleration= change in velocity

mantis shrimp

• smashers- smash prey to open, eating hard things

• spearers- spear prey, eat fish/soft bodied animals

• dactyl= strongest/fastest arm in animal kingdom

• their striking is ultrafast

  • 5000 frames/s

  • speed= 31m/s= 69 mi/hr

  • force= ~1500N (~337 lbs, 2500x animal’s body mass)

• cavitation forces- intense shockwaves generated by the rapid collapse of vapor bubbles created by their fast punch

• latch mediated strike- an ultra-fast, power-amplified strike where muscles load a spring-like structure, head by a latch, then released to produce acceleration

how does the mantis shrimp exert such high forces?

• power amplification

  • separation of slow loading energy, storage

  • rapid release of energy (like bow + arrow?)

animal energetic background

• forms of energy:

  • chemical- eating food (breaking/rearranging bonds)

  • electrical- separation of + and - charges (transfer of ions)

  • mechanical- energy of organized motion, external work

  • molecular kinetic- heat

• not all are equal

• physiological work- processes increasing order

• (high grade= chemical, electrical, mechanical)

• (low grade= molecular kinetic)

ingested chemical energy

• energy in : energy out

  • energy flow in the system is not unidirectional

Fig 2.7- energy use:

• DORC= dynamic organized require energy change

• depends if baby or adult where energy will go

human growth differential

• v large

• form 0-1 yrs old u grow 10 inches, 3x mass, 2x brain mass

• crabs go through several molts: 6 times/year in ages 1-2

• lizard can drop tail- can grow back but won’t be same and requires lots of energy to do so

metabolic rate (MR)

• rate at which animals consume energy

• eating chem energy → [catabolic + anabolic] + losing energy as heat

basal metabolic rate (BMR)

• resting metabolic rate

• applies to homeotherms (animals that physiologically regulate their body temps- mammals + birds)

• animal’s MR when it is:

  • in its thermoneutral zone

  • fasting

  • resting

standard metabolic rate (SMR)

• applies to ectotherms (animals that allow their body temps to fluctuate freely w/ variations in environmental temps- amphibians, fish)

• animal’s MR when it is:

  • fasting

  • resting

routine metabolic rate (RMR)

• applies to fish exerting only small, spontaneous movements

  • exhibiting v minimal levels of activity

factors that affect MR of individual animals- large effects

• physical activity

  • MR increase w/ rising activity levels

• environmental temperature

  • mammals + homeotherms:

    • MR increases when both above + below thermoneutral zone

    • MR lowest in thermoneutral zone

  • fish + ectotherms:

    • MR increase w/ increasing temp

    • MR decrease w/ decreasing temp

factors that affect MR of individual animals- smaller effects

• ingestion of a meal (particularly protein rich)- MR inc following ingestion

• body size- weight-specific MR rate inc as size dec?

• age-

• gender

• environmental O2 level

• hormona status

• time of day

• salinity of water (aquatic mammals)

specific dynamic action (SDA)

• (ingestion of a meal (particularly protein rich)- MR inc following ingestion)

• calorigenic effect of ingested food

• heat increment of feeding

• the bigger the protein meal, the larger the spike in SDA + the longer it takes for MR to go back to baseline

  

body size

• does not affect MR too much

  • b/c we can calc MR by controlling for size- weight specific metabolic rate

patterns of scaling (understanding changes in size)

• isometry= changes in size, no changes in proportions

• allometry= changes in size are associated w/ changes in shape (disproportional)

  • positive allometry= trait increasing disproportionally to body size

  • negative allometry= disproportional decrease in size

scaling patterns

• as length (L) of organism increases:

  • linear measurements proportional to L1

  • surface area proportional to L2 (allometric)

  • volume proportional to L3 (increase the fastest, disproportional)

• can combine/extend to other properties:

  • force production in muscles proportional to L2

  • mass proportional to L3

generalized scaling equation

• “allometric equation” or “power law equation”

• y=Bx^A

  • y= biological variable

  • x= measure of body size

  • A= “scaling exponent”

  • B= constant

equation for metabolic scaling

• M=aW^b

  • b= 0.67 or 2/3

  • W= mass

• rubner’s surface law:

  • SA proportional to r² but V proportional to r³ → SA proportional to V²/3