2.4 Metabolism in Conformers and Regulators

Question 1

definition of the term adaptation?

Answer 1

special feature of an organism that helps them to survive

Question 2

Give examples of external abiotic factors (environment) and if it affects metabolic rate?

Answer 2

external abiotic factors such as temperature, salinity and pH can affect the ability of an organism to maintain its metabolic rate

Question 3

What is the internal environment?

Answer 3

the internal environment of an organism is made up of body cells and their surrounding tissue fluid, together with temperature, water content and glucose content

Question 4

What are conformers?

Answer 4

conformers cannot regulate their internal environment and therefore cannot control their metabolic rate?

Question 5

What do conformers body temp rely on?

Answer 5

depends upon the temperature of the external environment

Question 6

Examples of conformers?

Answer 6

reptiles and invertebrates

Question 7

What are advantages of conformers?

Answer 7

as conformers have no physiological mechanism for controlling metabolic rate, energy costs to the organism are low

Question 8

What are disadvantages of conformers?

Answer 8

Conformers can only occupy a narrow range of ecological niches and are less able to adapt to survive any changes in the external environment

Question 9

TOPTIP

Answer 9

Remember 3C's
conformers
cannot 
control
their internal environment by physiological means

Question 10

What are regulators?

Answer 10

In regulators metabolism is used to control the internal environment using physiological means

Question 11

Examples of regulators?

Answer 11

mammals and birds

Question 12

what is physiological homeostasis?

Answer 12

The internal environment remains stable despite changes in the external environment

Question 13

advantages of regulators?

Answer 13

they can occupy a wide range of ecological niches

Question 14

disadvantage of regulators?

Answer 14

energy costs to the organism are high due to physiological mechanisms needed to keep the internal environment stable

Question 15

TOP TIP

Answer 15

animals can be conformers for one factor and regulators for another

Question 16

Explain why conformers can only occupy a very narrow range of environments?

Answer 16

Conformers are less able to adapt to and survive changes to the external environment

Question 17

two examples of physiological mechanisms used by regulators to control their internal environment?

Answer 17

control of blood water concentration
blood glucose concentration
body temperature

Question 18

What is negative feedback?

Answer 18

any change in a condition from the optimum is detected by receptors that switch on a corrective mechanism to restore the condition to normal. The corrective mechanism is then switched off

Question 19

Negative feedback sequence?

Answer 19

receptors - detects changes in the internal conditions outwith normal limits

message - nervous or hormonal

effectors - organ which responds

corrective response - reverses the original change

Question 20

TOP TIP

Answer 20

negative feedback works like the thermostat in a central heating system. when the temperature in your house goes too high (that is above a set point) the thermostat switches off the heating and then switches back on when the temperature goes too low ( below the set point)

Question 21

Compare thermoconformers and thermoregulators?

Answer 21

mammals are thermoregulators and have a homeostatic mechanism to regulate their body temperature
the body temperature of a thermoconformer changes with the temperature of the external environment

Question 22

Importance of themoregulation to metabolic processes?

Answer 22

all chemical reactions in the body are controlled by enzymes
when body temp is below the optimum temp for enzyme function, metabolism is slow
metabolism is fastest when the body temp is close to the optimum temp for enzymes
above the optimum temperature for enzymes
above the optimum temp enzymes start to denature; metabolism slows down and eventually stops
temp also affects diffusion rates
rates of diffusion of substances such as oxygen or CO2 are faster at warmer temperatures, contributing to the ability to maintain high metabolic rates

Question 23

What are responses to temperature regulation voluntary?

Answer 23

removing clothes, opening windows, switching off heating in response to increase in body temperature
Putting on clothes, closing windows, putting on heating in response to decreasing body temperature

Question 24

Mechanism of temperature regulation sequence?

Answer 24

receptors - thermoreceptors in the hypothalamus in the brain

message - nervous impulses

effector - skin and body muscles

corrective response - return body temp to normal

Question 25

what are responses to temperature regulation in voluntary?

Answer 25

Skin arterioles
sweating
erector pili muscles
shivering
metabolic rate

Question 26

What happens when the body temp rises?

Answer 26

increase in body temperature
detected by thermoreceptors in the hypothalamus
increased sweating, body temp lowered blood diverted to skin surface, decrease in metabolic rate
body temp falls to normal

Question 27

What happens when the body temp falls?

Answer 27

decrease in body temp
detected by thermoreceptors in the hypothalamus
decrease in sweating, body hair raised, shivering, blood diverted from skin surface, increase in metabolic rate
body temp rises to normal

Question 28

Involuntary responses to temperature change

Response to decrease in body temperature?

Answer 28

vasoconstriction - narrowing of skin arterioles diverts blood away from the skin surface, reducing heat loss by radiation
sweating stops
erector pili muscles contract, pulling body hairs into a raised position that traps air to insulate the duvet (like a duvet)
shivering increases muscle activity and generates heat
metabolic activity increases to generate heat

Question 29

Involuntary responses to temperature change

Response to increase in body temperature?

Answer 29

vasodilation - dilation (widening) of skin arterioles divert more blood to capillaries at the skin surface increasing heat loss by radiation
Increased sweat production causes more heat from the skin to be used to evaporate the sweat, lowering body temperature
erector pili muscles are relaxed allowing body hair to lie flat against the skin, minimising the insulating effect
no shivering
metabolic activity decreases to reduce heat production

Question 30

TOP TIP

Answer 30

body temperature can increase due to exercise, illness and exposure to a hot environment
body temperature can decrease due to exposure to in cold external environment

Question 31

TOP TIP

Answer 31

Giving alcohol to a person who is very cold causes vasodilation. Increasing heat loss from the body which can lead to hypothermia

Question 32

TOP TIP

Answer 32

metabolic rate decreases when body temperature increases

metabolic rate decreases when body temperature decreases

Question 33

Why is body temperature important in carrying out metabolic processes?

Answer 33

to provide optimum temperature for optimum enzyme activity or diffusion rates