maintaining a balance enzymes 1.1

Question 1

identify the role of enzymes in metabolism and describe their chemical composition. also a simple model describing there specificity on substrates

Answer 1

enzymes are catalysts, this means they speed up or bring about chemical reactions without themselves being used up in the reaction. each enzyme is used for specific reactions and substrates.
enzymes are globular proteins who’s shapes match specific substrates ( active site molds slightly to match substrate), they are also made up of hydrogen bonds and have an active site.

Question 2

identity the PH level as a way of describing the acidity of a substrate.

Answer 2

Ph is a measurement of hydrogen ions that are released by acids in a solution.
0-6 represents acidic, 7 is neutral, 8-14 is basic.

Question 3

identify data sources, plan, choose equipment or resources and preform a first hand investigation to test the effect that temperature, change in PH and change in substrate concentration has on the activity of named enzyme(s).

Answer 3

four test tubes filled with milk and rennet set at differing temps, ph’s or substrate concentrations. each is tested and timed for reactions or none reactions which will identify the effect different external changes have on the enzymes.
Temp change: 0,37,50,100, with lower temps the enzymes will slow and or stop stopping all reactions
pH change: to much or to little PH denatures the enzymes thus slowing and stopping efficiency
substrate concentration: the more concentrated the slower it takes to react.

Question 4

explain why the maintenance of a constant internal environment is important for optimal metabolic efficiency

Answer 4

maintenance of a constant internal environment is important because enzymes control the metabolic processes and require consistency of temp and pH levels to work efficiency thus needs continuous internal equilibrium to function effectively.

Question 5

describe homeostasis as the process by which organisms maintain a relatively stable internal environment

Answer 5

homeostasis is the process by which the internal environment is kept within normal limits regardless, of the external environmental conditions and behavioral changes. homeostasis maintains, temp, PH, gas levels, water and salt concentrations. this allows optimal enzyme efficiency.

Question 6

explain that homeostasis consists of two stages: 1.detecting changes from a stable state
2.counteracting changes form the stable state.

Answer 6

two systems controls the feed back mechanism that is homeostasis, the nervous system and the hormone system.
stage one: receptors detect changes in the organism’s internal environment message is sent the the hypothalamus in the brain which is stimulated.
stage two: the hypothalamus responds to counter act change to maintain continuous stable internal state eg shivering sweating if external issue is temp related.

Question 7

describe a feedback system, graph

Answer 7

stimulus——feedback system——– response .

negative: trying to bring back to stable state ( sweat, shivering)
positive: encouraging change ( child birth)

Question 8

outline the role of the nervous system in detecting and responding to environmental changes.

Answer 8

consists of two parts: central nervous system (brain, spine) and the peripheral nervous system ( nerves and nerve endings.
example: change in temp. sensors in the skin detect change in temperature and the sensory neurons conduct impulses to the hypothalamus, nerve impulse pass this information form the receptors to the effector neurons then conduct to the effectors like sweat glands, muscles and blood vessels to adjust to the change.

Question 9

identify the board range of temperatures over which life is found compared with the narrow limit for individual species

Answer 9

life can be found int temps are extreme as -40 to 120 degrees however the majority of living organisms between -2 to 40. Below 0 cells are at risk of crystals forming in them and above 45 degrees the enzymes have a chance of denaturing.

Question 10

compare responses of named Australian ectothermic and endothermic organisms to changes in the ambient temperature and explain how these responses assist temperature regulation

Answer 10

endotherm: red kangaroo
- shelters during heat of the day.
- licks inside of paws where skin is thinner thus blood closer to surface, evaporation from saliva promotes loss of heat from blood.
- pants and wets
ectotherm: desert lizard
- burrows and seeks shelter to avoid hot parts of day.
- basking in sun to increase body temp.
- raising body up from heat of sand allowing wind to carry away heat.
- changing colour

Question 11

describe what an endothermic animal is and features it may have

Answer 11

endotherms: can generate there own body heat thus maintaining constant body temperature. body temp is mainly controlled via adaptive mechanisms: sweat, panting, insulation ( fur blubber, feathers ect).

Question 12

describe what an ectothermic animal is and features it may have

Answer 12

cannot generate own body heat thus body heat is maintained via manipulation of their external environments ( sun baking, shelter seeking). environmental body temp regulating.

Question 13

identify some response of plants to temperature changes

Answer 13

• certain temperatures needed for growth.
• drops leaves if temps become too cold
• leaves drop down to avoid complete connection of sun light thus not over heating.
• closing stomates in response to high temperatures to reduce water loss.
• varying germination.