Respiration: Introduction & Basic Formulas

Question 1

physiology

Answer 1

• study of how living animals function

Question 2

what topics does physiology connect/integrate (3)

Answer 2

• genes
• environment
• population

Question 3

comparative physiology

Answer 3

• comparisons between species to discover physiological and evolutional patterns

Question 4

environmental physiology

Answer 4

• evolutionary adaptations to the environmental that the animals are found in

Question 5

evolutionary physiology

Answer 5

• methods of evolutionary biology and systematics using physiology rather than anatomical/molecular markers to understand evolutionary patterns

Question 6

physiology: link between structure and function (2)

Answer 6

• links between structure and function exist at every level, including protein level
• specific amino acid residues alter protein tertiary and quaternary structure affecting protein or enzyme structure

Question 7

acclimatization

Answer 7

• adjustment that occurs when an animal moves to another natural environment

Question 8

acclimation (2)

Answer 8

• adjustment in response to a change in only one environmental variable
• adjustments are short term and reversible

Question 9

adaptation (3)

Answer 9

• refers to physiological trait that has been selected for over generations and is generally non-reversible
• based upon variability, heritability
• must confer differential survivorship to offspring to be selected for

Question 10

homeostasis (2)

Answer 10

• the tight regulation of the composition of cellular and intracellular space in most animals, relative to the external environment
• the tendency toward internal stability

Question 11

negative feedback system (2)

Answer 11

• pathway triggered by deviation in output
• produces changes in output in the opposite direction of the initial deviation

Question 12

positive feedback system (2)

Answer 12

• pathway triggered by deviation in output
• produces changes in output in the same direction of the initial deviation

Question 13

conforming

Answer 13

• system behaviour depends on changes in external environment

Question 14

how do unicellular and small multicellular organisms participate in gas exchange

Answer 14

• rely on diffusion

Question 15

why do unicellular and small multicellular organisms rely on diffusion for gas exchange (2)

Answer 15

• these organisms are very small, so there is sufficient surface area to volume ratio
• diffusion oxygen is sufficient to support metabolism

Question 16

how do larger organisms participate in gas exchange

Answer 16

• rely on combination of bulk flow and diffusion

Question 17

bulk flow systems (2)

Answer 17

• ventilation
• circulation

Question 18

bulk flow: ventilation

Answer 18

• moving medium (air or water) over respiratory surface (lung or gill)

Question 19

bulk flow: circulation

Answer 19

• transport of gases in circulatory system

Question 20

Fick equation

Answer 20

dQ/dt = D x A x (dC/dx)

Question 21

Fick equation: dQ/dt

Answer 21

rate of diffusion

Question 22

Fick equation: D

Answer 22

diffusion coefficient

Question 23

Fick equation: A

Answer 23

area of membrane

Question 24

Fick equation: dC/dx

Answer 24

• gradient

Question 25

dC/dx: gases

Answer 25

- for gases, it is the partial pressure gradient (not concentration) per unit distance

Question 26

what does the Fick equation tell us about

Answer 26

- the rate of diffusion

Question 27

Fick equation: O2 transfer

Answer 27

MO2 = K A (PO2a/w - PO2b) / t

Question 28

Fick equation: MO2

Answer 28

- oxygen consumption/transfer rate

Question 29

Fick equation: K (2)

Answer 29

- Krogh's diffusion constant - diffusion coefficient (D) x solubility

Question 30

Fick equation; oxygen version: A

Answer 30

- surface area of the barrier that oxygen must cross

Question 31

Fick equation: PO2a/w

Answer 31

- partial pressure of O2 in air or water

Question 32

Fick equation: PO2b

Answer 32

- partial pressure of O2 in blood

Question 33

Fick equation: PO2a/w - PO2b

Answer 33

- partial pressure gradient for O2 between blood and air/blood and water

Question 34

Fick equation: t

Answer 34

- thickness of barrier

Question 35

what characteristics of a barrier will maximize the rate of gas diffusion (3)

Answer 35

- high partial pressure gradient - most possible barrier SA - thinnest possible barrier thickness

Question 36

Dalton's Law of Partial Pressure (2)

Answer 36

- in a gas mixture, each gas exerts its own partial pressure - the sum of all partial pressures is equal to the total pressure of the mixture

Question 37

what determines the pressure exerted by a gas (2)

Answer 37

- the number of moles of the gas - the volume of the chamber

Question 38

what gases make up air (4)

Answer 38

- nitrogen - oxygen - argon - carbon dioxide

Question 39

what drives gas diffusion

Answer 39

- partial pressure

Question 40

Henry's Law in words

Answer 40

- concentration of gas in liquid is proportional to its partial pressure

Question 41

Henry's Law

Answer 41

[G] = Pgas x Sgas

Question 42

Henry's Law: [G]

Answer 42

- concentration of the gas (moles/l)

Question 43

Henry's Law: Pgas

Answer 43

- partial pressure of the gas (mmHg)

Question 44

Henry's Law: Sgas

Answer 44

- solubility of the gas (moles/l/mmHg)

Question 45

how do gas molecules diffuse into cells

Answer 45

- gas molecules in air must first dissolve in liquid to diffuse into a cell

Question 46

why will there be higher [O2] in air than water in the same PO2

Answer 46

- solubility of O2 in water is lower than in air

Question 47

what is the ratio (water:air) of O2 solubility (2)

Answer 47

- 1:30 - for every single oxygen molecule in water, there are 30 in the air

Question 48

describe the relationship between oxygen partial pressure and concentration in air or water (2)

Answer 48

- concentration of O2 is proportional to partial pressure in air and water - concentration is always lower in water than in air in the same PO2 due to differences in solubility

Question 49

what is the ratio (water:air) of CO2 solubility (2)

Answer 49

- ~1 - for every single CO2 molecule in water, there is a single CO2 molecule in the air

Question 50

compare the CO2 and O2 solubility in water (2)

Answer 50

- CO2 is 30 times more soluble than O2 in water - large implications for gas exchange

Question 51

diffusion of gases

Answer 51

- movement of molecules from high partial pressure to a low partial pressure

Question 52

diffusion rates (2)

Answer 52

- slow over long distances - fast over short distances

Question 53

Boyle's Law (2)

Answer 53

- P1V1 = P2V2 - only applies to gases

Question 54

Boyle's Law: P1V1

Answer 54

- initial pressure and volume of gas

Question 55

Boyle's Law: P2V2

Answer 55

- final pressure and volume of gas

Question 56

what is the compressibility of air and water (2)

Answer 56

- air is very compressible - water is virtually incompressible

Question 57

why doesn't Boyle's Law apply to liquids

Answer 57

- liquids are virtually incompressible

Question 58

rate of flow equation

Answer 58

Q =△P/R

Question 59

rate of flow equation: Q

Answer 59

- rate of flow

Question 60

rate of flow equation: △P

Answer 60

- difference in pressure

Question 61

rate of flow equation: R

Answer 61

- resistance to flow

Question 62

how do you increase the rate of flow (2)

Answer 62

- increase the difference in pressure - decrease the resistance to the flow

Question 63

how do volume and SA change as radius increases

Answer 63

- as radius increases, volume increases faster than surface area

Question 64

how do volume and SA change as organisms grow larger

Answer 64

- the ratio of SA to volume decreases

Question 65

why can't larger animals rely on diffusion (2)

Answer 65

- limited SA available for diffusion - increase in the diffusion distance

Question 66

respiratory strategies: what happens to beating rate of cilia in snail embryos during hypoxia (2)

Answer 66

- cilia on eggs begin to increase beating rate - increase flow of "new" water to embryos to access more O2, reducing boundary layer limitations

Question 67

why do boundary layer limitations exist at cell surfaces

Answer 67

- flow rate is reduced due to resistance and friction

Question 68

how can boundary layer limitations be broken

Answer 68

- increasing flow rate

Question 69

regulating

Answer 69

- control internal environment irrespective to external environment to an extent