homeostasis

Question 1

what is homeostasis

Answer 1

in mammals it involves the physiological control systems that maintain the internal environment within restricted limits

Question 2

what is the importance of homeostasis

Answer 2

to function properly and efficiently, maintenance of optimal conditions for enzyme action and cell function

Question 3

what detects info about conditions inside and outside the body

Answer 3

sensory cells

Question 4

what two coordination systems are used in the homeostasis mechanism

Answer 4

Nervous system and endocrine system

Question 5

what is the nervous system

Answer 5

CNS and PNS, nerve impulses pass along neurones

Question 6

what is the endocrine system

Answer 6

hormones (chemical substances) carried in the blood, to do with functions that don’t need instant responses

Question 7

what is the importance of a stable core body temperature

Answer 7

vital for enzyme activity

Question 8

what effect would a low temp have on enzyme activity

Answer 8

prevent or slow down reactions, less frequent collisions

Question 9

what effect would high temps have on enzyme activity

Answer 9

speeds up reactions, higher frequency of collisions, too high temps cause enzymes to denature

Question 10

what does a denatured enzyme mean

Answer 10

bonds (e.g h bonds) break causing a change in the tertiary structure of the enzyme which damages the active site

Question 11

what effect does PH have on enzyme activity

Answer 11

extreme PHs denature enzymes

Question 12

what is the importance of stable blood glucose

Answer 12

affects water potential and availability of respiratory substrates for cells, essential for cellular respiration

Question 13

what is the role of negative feedback

Answer 13

to maintain homeostatic balance

Question 14

what do negative feedback loops involve

Answer 14

a receptor to detect a stimulus, coordination system to transfer information and an effector to carry out a response

Question 15

what do negative feedback loops do

Answer 15

reduce the effect of the original stimulus

Question 16

what do positive feedback loops do

Answer 16

enhance the effect of the original stimulus

Question 17

what is blood glucose controlled by

Answer 17

two hormones secreted by endocrine tissue in the pancreas called the islets of Langerhans

Question 18

what do the islets of Langerhans contain

Answer 18

two cell types, a cells which secrete glucagon and b cells which secrete insulin

Question 19

when is glucose released

Answer 19

when blood glucose concentration is high

Question 20

what do muscle cells, fat cells and liver cells posses that aid in the action of insulin

Answer 20

glucose transporter proteins (target cells of insulin)

Question 21

what do glucose transporter proteins do (GTP)

Answer 21

allow the uptake of glucose via facilitated diffusion

Question 22

GTP are ……

Answer 22

insulin sensitive

Question 23

what is the action of insulin

Answer 23

insulin binds to receptors on the surface of target cells, activates GTP, permeability of cells to glucose increases and so does the rate of facilitated diffusion, glucose enters cells and causes glycogenesis

Question 24

what is glycogenesis

Answer 24

A glucose enters liver cells and an enzyme converts it to glucose phosphate, different enzymes convert glucose phosphate into glycogen, lowers concentration of glucose within liver cell, steep diffusion gradient is maintained between blood in capillaries and liver cell