respiration II

Answer key

Activity I

  

1.  /      2. /       3. X     4. /       5. /       6. X     7./        8./        9./        10. X

Activity 2

V :  Oxygen                                                    Y : erythrocyte

W :  Carbon dioxide                                       Z :  blood capillary

X : Alveolus

Activity 3

X :  carbon dioxide                             Y :  oxygen

Activity 4

Process	Photosynthesis	Respiration
Occurrence	Occurs in all green plants	Occurs in all living organism (plants and animal)
Purpose	Stores energy	Release energy
Raw materials	Water and carbon dioxide	Glucose and oxygen
Products	Glucose and oxygen	Energy, water and carbon dioxide
Energy reguirement	Light energy is needed	Light energy is not needed
Site	Take place in chloroplast	Takes place in mitochondria
Presence of chlorophyll	Required	Not required
Equation	Carbon dioxide + water→ glucose + water + oxygen	Oxygen + glucose → carbon dioxide + water+ energy

Activity  5

Section A

1. A      2. B      3. A      4.D       5.D       6.B       7.D       8.C       9.A       10.C

Section B

1.       a. Alveolus

          b      i.   The presence of a large network of blood capillaries

      ii.   The wall is thin, composed of just one layer of cells.

           c. Diffusion

           d    i. Haemoglobin

                 ii.iron

           e.   Carbon dioxide is transported as hydrogen carbonate ions, carbonic acid and as carbaminohaemoglobin.

           f.     i.  carbon monoxide combines with haemoglobin in the blood to form

          crboxyhaaemoglobin.

      ii. The affinity of carbon monoxide to haemoglobin is about 250 times more    than oxygens affinity to haemoglobin.The number of erythrosytes required to transport oxygen decreases in the presence of carbon monoxide. This results in the cells and carbon monoxide.This results in the cells and tissues getting less oxygen than needed. Formation of carboxyhaemoglobin in high concentration can be dangerous to the cells and tissues because it is toxic.

    iii.  By not smoking

          By wearing safety devices in areas exposed to toxic gases or smoking.

2.  a. i. in dark condition ,no oxygen is

            released only carbon dioxide is release.

         ii. in dark conditions , oxygen is used for resperation and carbon deoxide

              is released.

      b.  0.050,  0.020  , 0.0125,  0.0091.

      c.   i.  light intensity

                photosynthetic rate / oxygen relesed

                temperature, carbon dioxide concentration.

 ii. At the  compensation point, the rate of photosynthesis is egual to the  respiration rate  at certain light intensity.

        d.i.

                       

        ii.    1.     -  in dark conditions photosyntesis does not occur.

                                            only the respiration process release carbon dioxide.

                                         -  in bright conditions, carbon dioxide is used for photosyntesis.

         2      – in dark condition, respiration occurs using oxygen.

                 -  in bright conditions photosynthesis occurs faster then   respiration. Thus, oxygen  is released.

            e.    i. 0.007 cm^-1

                             ii.  The higher the light intensity, the higher the photosynthesis rate.

            f.     i.  Compensation point is the light intensity where photosynthetic rate is    equal to respiration rate.

            g.    i.    Photosynthetic rate is slower then respiration rate.

                   ii     Photosynthetic rate is equal then respiration rate.

                   iii.    Photosynthetic rate is faster  then respiration rate.

Section C

Essay

1 a i. - During vigorous exercise    - more energy is  needed

         - So the rate of blood circulation increased in order to supply more glucose and   oxygen to the  muscles.  

      - This causes more cells respiration to produce sufficient energy.

      - The blood circulation also need in order to remove carbon dioxide formed during rapid cell respiration process.

    ii.- The pulse rate takes some time to return normal after exercise  because a large amount of oxygen is still required by the muscle cell.

        -the oxygen is needed to break down the lactic acid.- from anaerobic respiration   during the  vigorous exercise.

        -The oxygen debt is said to be paid and the pulse rate return to normal.

        -The heart rate is also high during the recovery period so as to circulate the blood rapidly

b. The pulse rate and breathing rate of an athlete smoker would be higher than a  non   smoker.

            - cigarette smoke-

i.- contain carbon monoxide which combines readily with haemoglobin.

                Thus reducing the amount of oxygen absorbed by red blood cells

              -  Heart then needs to pump faster to increase to supply sufficient

                  oxygen for rapid cell respiration.

            ii. Nicotine and carbon monoxide result in the narrowing of arteries and

                fatty deposits in arteries.

                -Hence, the heart has to pump faster and harder to circulate blood

                  through these narrow blood vessels.  

c.                i. Oxygen which diffuses from the alveolus into the blood capillary combines with the haemoglobin in the red blood cells to form oxyhaemoglobin. Oygen is then ,   transported to all body cells in the from of oxyhaemoglobin .Carbon dioxide which  diffuses from the body cells will combine with haemoglobin to form   carbaminohaemoglobin. This enables the carbon dioxide to be transported to the lungs and to be expelled during exhalation

     ii.  After vigorous exercise, the rate of breathing increases so that, more o₂

   can be supplied to body cells while more co₂ can be transported

                     rapidly to the lungs to be removed. The cells need more o₂ to pay off the 0₂

debt incurred during vigorous exercise. The rapid cell respiration produces  a large amount of co₂ which can be expelled rapidly through the increased rate of breathing.

     iii. During vigorous exercise, the muscles need a large amount of o₂, but the supply  of o₂ is less than the demand. Hence the muscles have to carry out anaerobic respiration which produced lactic acid. The  accumulation of lactic acid in the muscles causes the muscles to ache and be tired. The amount of energy produced during anaerobic respiration is small and not  sufficient for muscular activity. Hence, the body becomes tired after vigorous exercise.