Lab Practical

Front 1

scaling

Back 1

Scaling –as body size increases, surface area (SA) is higher, BUT SA is lower relativeto mass (SA/Mass becomes smaller).

Front 2

viscous forces / fluid dynamics

Back 2

· Inertialforces (mass X velocity) cause an animal to continue forward, coasting frominertia. · Viscous forces(stickiness to the fluid or gas) slow it down. · Fish, whales,and birds have high inertial forces forces relative to viscous forces. o To them, water is not sticky· Sperm andsingle-celled Eukaryotes (such as Paramecium) have low Inertial forces relativeto viscous forceso To them, water is sticky like molasses, tar, or thick glue· Bacteria are1/1000 to 1/1,000,000 the size of single celled Eukaryotes. They have highsurface area relative to their mass. That gives them REALLY low inertial forces relative to viscous forceso To bacteria, water is sticky like very thick mud or gooeyclay!

Front 3

ways to get through vicosity

Back 3

sperm, single celled eurkaryotes use flagella to get through water, but bacteria are even smaller and use cork-screw like motion to get through water (which is very sticky!)

Front 4

covalent, hydrogen, ionic bonds

Back 4

covalent: sharing of electrons
ionic: electromagnetic, one gains, one loses

hydrogen: electronegative to something like oxygen, consequently hydrogen has slight positive charge

Front 5

transcription and translation

Back 5

transcription: factor binds to enzyme, separates two strands of dna helix, break hydrogen bonds, form sugar backbone into new synthesized rna strand

translation: initiation- trna attaches to start codon, elongation (amino acid attaches) translocation (moves to next starting amino acid chain) termination when stop codon reached

Front 6

homeostasis

Back 6

definition: variables are regulated, internal conditions remain stable/constant

osmoconformer: osmotic pressure equal to environment, marine animals, minimizes influx of water in/out of cells

osmoregulator: has to maintain osmotic pressure, expel things thru kidneys etc

Front 7

regulatory elements for homeostasis

Back 7

set point: normal value of physiological variable

sensory/integration neurons

effector: acts in response to a stimulus

Front 8

body regulation of water

Back 8

A constant supply is needed to replenish the fluids lost through normal physiological activities, such as respiration, sweating, and urination.

The macula densa region of the kidney's juxtaglomerular apparatus is another modulator of blood osmolality. The macula densa responds to changes in osmotic pressure through changes in the rate of chloride anion flow through the nephron.

An insufficiency of water results in an increased osmolarity in the extracellular fluid.Increased osmolarity is sensed by osmoreceptors.

-When cells are more concentrated than environment (e.g., in fresh water)- Must excrete water and conserve ions. - Actively transport salt INTO body at gills; kidneyproduces dilute urine to get rid of excess water-When cells are less concentrated than environment (e.g., in salt water)- Actively transport salt out of body in gills; kidney producesconcentrated urine with excess salts & nitrogenous waste.

Front 9

4 ways to gain or lose heat

Back 9

Radiation is the process where heatemanates from an object that cannot hold any more thermal energy. can happen in a vacuum

convection: transfer of heat through a fluid caused by molecular motion;warmer air or liquid — which has faster moving molecules, making it less dense — rises, while the cooler air or liquid drops down.

conduction: movement of heat from one surface to another

evaporation: the heat absorbed per unit mass of a given material at its boiling point that completely converts the material to a gas at the same temperature: equal to the heat of condensation

Front 10

2 continuums of heat styles; poikilothermy and homeothermy

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A poikilotherm is an organism whose internal temperature varies considerably. Usually the variation is a consequence of variation in the ambient environmental temperature.

Homeothermy is thermoregulation that maintains a stable internal body temperature regardless of external influence. This internal body temperature is often, though not necessarily, higher than the immediate environment

Front 11

source of heat in the body?

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ectothermy: an organism in which internal physiological sources of heat are of relatively small or quite negligible importance in controlling body temperature.

endothermy: physiological generation and regulation of body temperature by metabolic means : the property or state of being warm-blooded.

NOTE: sources of heat can be combined with continua in any combination

Front 12

countercurrent heat exchange

Back 12

IMPORTANT: only 1 source, 1 sink

must be from higher to lower

In simple terms, the veins in these locations run parallel to the arteries. As the arteries carry warm blood from the heart to the paw, heat is transferred to the neighboring veins. Since the arterial blood is cooler when it reaches the paws, less heat can be lost through the paws to the environment

Front 13

hypertonic / fish

Back 13

Freshwater fish are naturally hypertonic, which means that they have a higher solute concentration than their surrounding water. This causes two things:1) Water is always flowing into the fish towards the high concentration of solute. 2) Salt is diffusing out of the fish toward the lower concentration in the water.

Front 14

urea/uric acid

Back 14

ammonia/ammonium ion nh3<>nh4+

uric acid has even more carbons so it crystallizes at low concentration- not great in a kidney

Front 15

protonephridium

Back 15

flatworms

Front 16

metanaphridium

Back 16

annelids

Front 17

counter current heating diagram

Back 17

Front 18

green gland

Back 18

coelomosac: filtration (end sac)

reabsorb valuable nutrients in labyrinth and nephridial canal

Front 19

nephridia excretory drawbacks

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MUST ALL have access to water bc they are efficient at removing wastes, not so much at concentrating urine to retain water

Front 20

mammal excretory cell: nephron

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- Instead, cup structure surrounds a ball ofcapillaries (Fig. 30.11 & 30.12)& collects fluid filtered out of the capillaries & through the basementmembrane (= basal lamina)- Hydrostatic pressure forces the fluid out of theblood in the capillaries- Filtrate contains water, urea, inorganic ions, sugar, amino acids,small waste molecules, and so on- Proteins & cells cannot pass through membrane

Front 21

nephron chemicals and process

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- How is urine concentrated? (Fig. 30.14)- By a "Counter-current multiplier" in thefirst loop of the nephron (Because, 1) Active transport of saltout of rising limb of the nephron diffuses into descending blood supply ofnephron- Carrying salt to the medulla (medulla = interior region of kidney)- Water leaving the descending loop of Henle is carried away by bloodvessels

Front 22

malphigian tubules

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- Blind-ended tubules emptying into gut- K+ actively pumped into tubule (Cl- follows passively due to charge), water &other small molecules diffuse into tubule; large molecules apparently moved invesicles (endocytosis of coelom fluid into tubule cells & then exocytosisof contents into tubule lumen)- Valuable molecules are reabsorbed from hindgut- Insects excrete nitrogenous compounds as uric acid- Uric acid is not very soluble in water, so- As insects keep adding uric acid from theMalpighian tubules into their rectum, uric acid keeps precipitating out ofsolution to form crystals- Because uric acid keeps precipitating out as crystals,the solute concentration of the urine stays low- Water can then be reabsorbed by the following mechanism: K+ is pumped out of the rectum (Cl-follows passively), and water follows by osmosis- This allows insects to conserve water, and is one major adaptationallowing them to live in dry terrestrial environments

Front 23

human kidney overview

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- TO SUMMARIZE to this point:Salt is pumped out of the ascending loop into the interstitial fluid and THENsome of the salt enters the descending part of the blood supply, which carriessalt deep into the medulla. Theascending part of the blood supply passes close to the descending loop ofHenle. Water leaving the descending looppassively enters the blood capillaries & is carried away back to the heart.(This causes, 2) The filtrate/urineflowing down a final descending tube (the collecting duct) passes this regionof high solute concentration, allowing reabsorption of H2O (see below)

ADH: water conservation hormone, moves it through pores, if no adh, expels lots of water with waste and wastes water

Front 24

tubules

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-Fluid enters through open end, or simply diffuses in through gaps between orthrough cells- Entering fluid has been filtered [in insect Malpighian tubules,some/much simply diffuses through cells, following ions excreted into tubule]- Either on leaving a closed circulatory system orentering from coelomic fluid (or filtered in both places)- Gaps between (or through) cells are small enough to prevent largemolecules, such as plasma proteins, from entering fluid - All small molecules enter tubules with fluid, and those that areneeded by the body are reabsorbed -Tubules have transport proteins that (1) Actively remove valuable solutes from the "urine"- Save sugars, amino acids, ions, other valuablesmall molecules(2) Actively excrete some waste solutes into the fluid- Ions that are in excess, also urea or uric acid,other acids, & waste molecules that have been tagged with an attachedsulfate

Front 25

adjust heat & flow

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- Both endotherms and ectotherms use methods to adjust bodyheat, including behavior and internal changes (Fig. 30-16 & 30-17, 30-18)- Adjust intake or loss from radiation of infrared heat - Adjust evaporation(cooling)- Adjust position in wind/still air or water (convection gain/loss)- Adjust direct exchange of heat with solids (conduction gain/loss)- For Endotherms, also adjust heat production - Adjust blood flow:- Control of circulatory fluid flow to surface- Close small blood vessels to reduce heat loss- Open small blood vessels to increase heat loss

Front 26

biological heat exchanger

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Metabolic Rate -Amount of energy used per unit time (for aerobes, directly related to O2consumption)-Amount of energy measured in Calories: one Calorie is Amt of heat necessary to raise temperature of 1 gm water1° C- BasalMetabolic Rate is the MR at rest at a temperature in which an endothermicanimal needs do nothing physiological to gain or lose heat Smaller endothermshave higher metabolic rates per gram of tissues

Front 27

temperature going wrong

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- The temperatures over whichan endotherm needs to do nothing special to gain or lose heat is the"thermoneutral zone" for that endotherm -At temperatures below the thermoneutral zone the metabolic rate must increaseto maintain body temperature-At higher temperatures, the metabolic rate increases (as animal responds to tryto reduce temperature) until homeostasis fails, and crucial proteins begin todenature

fever: hypothalamus increases set point, increasing heat productionand decreasing heat loss; the higher temperatures helps the animal fight offinfection better than it helps the invading pathogen

- Hibernation:hypothalamus changes set point, allowing body temperature to drop (deadly ifunprepared!)