Sunday, July 22, 2012

latihan ulangkaji nutrition

1.                     (a)        Label A to F

                        A-mouth, B-oesophagus, C-stomach, D-pancreas, E-small intestine,
F-large intestine

Digestive process
Salivary amylase
Starch + water à maltose



Protein + water à polypeptides

Rennin coagulates milk by converting the soluble milk protein, caseinogens, into the insoluble casein.


Small intestine
Pancreatic juice:
Pancreatic amylase

Intestinal juice:

Starch + water à maltose

Polypeptides + water à peptides
Lipid droplets + water à glycerol +fatty acids

Peptides + water àamino acids
Maltose + wateràglucose
Sucrose + wateràglucose + fructose
Lactose + wateràglucose + galactose

 2.         Figure below shows the digestion of cellulose by a ruminant such as a cow.          

(a)        Label the following parts

                        Rumen                        Reticulum        Omasum         Abomasum

(b)        Complete the table below:

Processes involved
Cellulose is broken down by the cellulose produced by bacteria.  Part of the breakdown products are absorbed by the bacteria, the rest by the cow.

Cellulose undergoes further hydrolysis.  The cud is regurgitated into the mouth to be chewed making the cellulose softer and easier to be broken down.
Food is broken down into smaller pieces by peristalsis.  Water is removed from the cud.

Gastric juice containing digestive enzymes completes the digestion of proteins and other food substances.

3.         What is meant by assimilation?

A process whereby nutrients are used to form complex compounds or structural components in the cells.

4.         Using the above figure, describe how body cells use glucose, amino acids and lipids.

            Most of the glucose is converted into glycogen and stored in the liver.  When the blood sugar level falls and the body needs energy, the stored glycogen is converted back to glucose.  When the glucose molecules reach the cells, they are oxidized to release energy during cellular respiration.  When the glycogen stored in the liver is full, excess glucose is converted into lipids by the liver.

            Amino acids which enter the cells are used for the synthesis of new protoplasm and the repair of damaged tissues.  They are also important building blocks in the synthesis of enzymes and hormones.  Excess amino acids cannot be stored in the body and are broken down in the liver by a process called deamination.

            Lipids such as fats represent the major energy store of the body. Excess lipids are stored in the adipose tissue.  Phospholipids and cholesterol are major components of plasma membranes.

            5.         Identifying the macronutrients, the functions and effects of deficiency.

Effects of deficiency
Synthesis of nucleic acids, adenosine triphosphates (ATP) and phospholipids of plasma membranes. 

Poor root growth and formation of dull, dark green leaves.  Red or purple spots on old leaves.

Protein synthesis, carbohydrate metabolism and as a cofactor for many enzymes.  Maintains turgidity in plants.

Reduced protein synthesis, yellow-edged leaves and premature death of plants.

A major constituent of the middle lamella of cell walls.  Formation of spindle fibres during cell division.

Stunted growth, leaves become distorted and cupped, areas between leaf veins become yellow.

The main structural component of chlorophyll.  Activates many plant enzymes.  Involved in carbohydrate metabolism.

Yellowing in the regions between the veins of mature leaves.  Red spots on leaf surfaces, leaves become cupped.

A component of certain amino acids, a constituent of vitamin B and some coenzymes.

General yellowing of the affected leaves or the entire plants.

6.         Complete the table below:

Functions/Adaptations for photosynthesis


Epidermal cells are transparent.  This allows light to penetrate the leaf and reach the light-trapping chloroplasts inside.
Transports water absorbed by the roots to the leaf.
Transports organic products of photosynthesis away from the leaf.

Guard cells
Regulate the size of the pore.

Palisade mesophyll
Packed tightly together in an upright arrangement near the upper surface of the leaf so they receive maximum amount of light.  These cells have a high density of chloroplasts.

Spongy mesophyll
Cells are loosely arranged and between each of them are air spaces that connect the mesophyll with the stomata.  These large spaces allow easy diffusion of water and carbon dioxide through the leaf to the palisade cells.  The irregular shapes of these cells increase the internal surface area for the gaseous exchange

7.         Comparing and contrasting the light reaction and dark reaction.

Light reaction
Dark reaction
Light energy required

Site of reaction

Water, Carbon dioxide, chlorophyll, light energy
Substances required for reaction

Hidrogen atoms

Hydrogen ions, hydroxyl ions.
Products of reaction

Glucose, oxygen

8          (a)        A balanced diet is the consumption of foods containing all the seven
                        classes of food in appropriate proportion as required by the individual.

            (b)        (i)         Ahmad : 60% ; Leela : 44.6%
                        (ii)        Ai Mei : 34.3% ; Leela : 30.9%
                        (iii)       Ahmad : 20% ; Ai Mei : 16.3%

©         A male teenager requires more energy (calory) for growth and development of body features compared to a female teenager.

(d)       Leela requires greater amount of energy compared to Ai Mei for the growth and development of the foetus in her womb.

(e)        The intake of carbohydrates and proteins by Ahmad and Ai Mei is in appropriate proportions.  On the other hand, Leela consumes excessive proteins and this may lead to health problems.

9          (a)        (i)         A                     (ii)        C

            (b)        Labels : Epithelium, Blood capillary, lacteal

            ©         (i)         Absorption of digested food
(ii)        Long and folded structure to provide a large surface area of absorption
            Villus wall is semipermeable to allow certain substances to diffuse into the blood capillaries or the lacteal
            Movement of villi back and forth to make absorption faster

(d)       (i)         Organ D is a pancreas.  It removal causes the enzymes lipase,
amylase and trypsin to be no longer produced.  This disrupts the digestion of starch, peptones and peptides and also the hydrolysis of fats.

(ii)        Patient has to reduce the intake of foods containing starch because of the absence of pancreatic amylase which makes starch cannot be digested in the small intestine.

(e)        Cellulose in the vegetables cannot be digested in the body, hence, a vegetarian has a large portion of his food exiting the body as waste instead of being absorbed by the blood for cell metabolism.  The body will suffer from malnutrition.

10        (a)        Photosynthesis is the process of production of carbohydrates in plants
                        from inorganic materials in the presence of light.

            (b)        To supply or increase the concentration of carbon dioxide

©         Higher intensity of light increases the rate of photosynthesis because there is more energy for water photolysis and ATP production.

(d)       1          Concentration of carbon dioxide and temperature are fixed during
                        the experiment.
2.         Light is brought closes to the plant.
3.         Oxygen bubbles released is used to measure the rate of photosynthesis
11        (a)        (i)         P : Kwashiorkor
                                    Q : Obesity

                        (ii)        Deficiency of protein in diet

(b)        Children require more proteins for growth and labours require more carbohyrates to provide sufficient energy for work.

©         (i)         Excessive consumption of foods especially fats and carbohyrates

(ii)        The excess food will be stored in the form of fat (adipose tissue) under the skin and around the intestine.  Over the time, this will result in obesity.

(d)        1         The problem in individual Q is caused by the habit of over-eating, whereas anorexia nervosa is rooted to a psychological problem, that is, the obsession to maintain the body shape without assuming proper diet.

             2         The problem in individual Q brings about the effect of gaining 20% more weight than the normal weight, whereas anorexia nervosa results in loss of weight and malnutrition.

12        (a)        Human stomach has one compartment, while the cow’s stomach has 4
Cellulose digestion starts at the cow’s stomach, but for human, it starts in the colon.

            (b)        i.          Reticulum, rumen omasum, abomasums

ii          The abomasums is the ruminant’s true stomach.  In the abomasums, all the processes that take place in the human stomach take place here.  Here also the gastric juice that contains enzymes which assist in food digestion.

©         In the largest compartment, the rumen, there are millions of bacteria and protozoans.  These microorganisms produce cellulase enzyme that break down cellulose into starch.  The microbes get food and the cows get the food digested.

(d)       The stomach is a muscular bag whose principal function is acidification for the action of the pepsin and maceration of the food to the liquid state, and temporary storage until passes to the intestines.  The stomach is a highly acidic environment, which is necessary for the action of enzymes.  Digestive enzyme such as pepsin breaks down protein to peptides.  Rennin solidifies milk protein for pepsin to act upon them.

13        (a)        Absorb digested food

(b)        Lacteal.  It absorbs fatty acids and glycerol and joins the lymphatic system.

©         Q/lacteal – consist of fat droplets, vitamin A, D, E, K
            Blood capillaries – simple sugars, amino acids, minerals, vitamin B and C

(d)       The internal surface of the ileum is covered by finger-like projection called villi, folded into micro-villi which gives the ileum a far greater internal surface area for food absorption.
Inside each villus, there is a dense network of blood capillaries fo food absorption.

Thin wall to help in food absorption.

14        (a)       
(b)        Step 1 :            Boil the leaf to kill the cells and make its cells more
                                    permeable to iodine.

            Step 2 :            Boil the leaf in alcohol to remove the chlorophyll

            Step 3 :            Dip the leaf into boiling water again to soften the leaf

Step 4 :            Spread the leaf on a white tile and add iodine on it and observe changes.
            ©         i           A blue black colour indicates that starch is present
ii          Boil the leaf in alcohol by using a hot water bath to avoid the risk of fire.

            (d)       -palisade cells have more chloroplasts than spongy mesophyll cells
                        -xylem vessels are closer to palisade cells than phloem sieve tubes
                        -the presence of stomata in the lower rather than upper epidermis
                        -the presence of air spaces between the cells of the leaf


15        (a)        (i)         chloroplast


            (b)        i.          X : The light reaction in the grana
                                    Y : The dark reaction in the stroma

ii.         Photolysis of water, where water molecules are split to form oxygen and hydrogen ions

iii.        The reduction of carbon dioxide by the hydrogen ion to form glucose and water

            ©         24 H2O + 6 CO2                                                             C6H12O6 + 18H2O +6O2

The light reaction
The dark reaction
Occurs in the membrane of grana
Occurs in the stroma
Temperature sensitive
Temperature insensitive
Requires light energy
Reaction catalysed by an enzyme

Sunday, July 15, 2012

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

Occurs in all green plants
Occurs in all living organism (plants and animal)
Stores energy
Release energy
Raw materials
Water and carbon dioxide
Glucose and oxygen
Glucose and oxygen
Energy, water and carbon dioxide
Energy reguirement
Light energy is needed
Light energy is not needed
Take place in chloroplast
Takes place in mitochondria
Presence of chlorophyll
Not required
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
           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
      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.

        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

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.