Homeostasis

Question 1

Homeostasis:

Answer 1

Control systems in organisms that keep the internal conditions near constant.

Question 2

Physiological factors controlled by h.s.:

Answer 2

• Core body T.
• Metabolic wastes, CO2,Urea
• Blood ph
• Blood glucose conc.
• W.p. of the blood
• Conc. in the blood of the respiratory gases, O2 (Oxygen),CO2

Question 3

The features of t.f. That influenced cell activities:

Answer 3

1. T.
2. W.p.
3. Conc. of glucose.

Question 4

Excretion:

Answer 4

Removal of unwanted products of metabolism.

Question 5

2 products of excretion (larges quantities):

Answer 5

CO2 and Urea.

Question 6

Excretion, CO2:

Answer 6

• Produced by cells respiring aerobically.
• The waste CO2 is transported from respiring cells to lungs in the bloodstream.
• Gas exchange occurs in lungs, CO2 diffuses from blood into alveoli, and is excreted in the air we breath out.

Question 7

Excretion, Urea:

Answer 7

• Produced in liver.
• Produced from excess a.a. and is transported from liver to kidneys, in solution in blood plasma.
• Kidneys remove urea from blood and excrete it, dissolved in water, as urine.

Question 8

Deamination:

Answer 8

• Excess proteins can’t be stored in body, but getting rid of it would be wasteful, because a.a. provide useful energy.
• To use the energy the liver removes the amino group by deamination.
• In liver cells the a.g. of an a.a is removed + an H atom. These combine = becomes ammonia.

Question 9

Deamination, damage:

Answer 9

• Prevented by converting ammonia immediately to urea, which is less soluble and less toxic. This involves the urea cycle. This is ammonia and CO2 combine to form urea.