nutrition answer

7/29/2019 Nutrition Answer

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1. (a) Label A to F

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

F-large intestine

(b)

Part Enzyme Digestive processA

mouthSalivary amylase Starch + water maltose

C

stomach

Pepsin

Rennin

Protein + water polypeptides

Rennin coagulates milk by converting thesoluble milk protein, caseinogens, into

the insoluble casein.

E

Smallintestine

Pancreatic juice:PancreaticamylaseTrypsinLipase

Intestinal juice:ErepsinMaltaseSucrase

Lactase

Starch + water maltose

Polypeptides + water peptidesLipid droplets + water glycerol +fatty

acids

Peptides + wateramino acidsMaltose + waterglucose

Sucrose + waterglucose + fructoseLactose + waterglucose + galactose

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

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(a) Label the following parts

Rumen Reticulum Omasum Abomasum

(b) Complete the table below:

Part Processes involved

Rumen

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

Reticulum

Cellulose undergoes further hydrolysis. The cud is regurgitatedinto the mouth to be chewed making the cellulose softer and easierto be broken down.

OmasumFood is broken down into smaller pieces by peristalsis. Water isremoved from the cud.

Abomasum Gastric juice containing digestive enzymes completes the digestionof proteins and other food substances.

3. What is meant by assimilation?

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

Rumen

Reticulum

Abomasum

Omasum

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

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 storedglycogen is converted back to glucose. When the glucose molecules reachthe 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 newprotoplasm and the repair of damaged tissues. They are also importantbuilding blocks in the synthesis of enzymes and hormones. Excess aminoacids cannot be stored in the body and are broken down in the liver by aprocess called deamination.

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

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

Macronutrient Functions Effects of deficiencyPhosphorus Synthesis of nucleic acids,

adenosine triphosphates (ATP) andphospholipids of plasmamembranes.

Poor root growth and

formation of dull, dark greenleaves. Red or purple spotson old leaves.

Potassium Protein synthesis, carbohydratemetabolism and as a cofactor formany enzymes. Maintainsturgidity in plants.

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

Calcium A major constituent of the middlelamella of cell walls. Formation of

spindle fibres during cell division.

Stunted growth, leavesbecome distorted and

cupped, areas between leafveins become yellow.

Magnesium The main structural component ofchlorophyll. Activates many plantenzymes. Involved in carbohydratemetabolism.

Yellowing in the regionsbetween the veins of matureleaves. Red spots on leafsurfaces, leaves becomecupped.

Sulphur A component of certain aminoacids, a constituent of vitamin B

and some coenzymes.

General yellowing of theaffected leaves or the entire

plants.

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6. Complete the table below:

Structure Functions/Adaptations for photosynthesis

Epidermis Epidermal cells are transparent. This allows light topenetrate the leaf and reach the light-trappingchloroplasts inside.

Xylem Transports water absorbed by the roots to the leaf.

Phloem Transports organic products of photosynthesis awayfrom the leaf.

Guard cells Regulate the size of the pore.

Palisade mesophyll Packed tightly together in an upright arrangement nearthe upper surface of the leaf so they receive maximumamount of light. These cells have a high density ofchloroplasts.

Spongy mesophyll Cells are loosely arranged and between each of them areair spaces that connect the mesophyll with the stomata.These large spaces allow easy diffusion of water andcarbon dioxide through the leaf to the palisade cells.

The irregular shapes of these cells increase the internalsurface area for the gaseous exchange.

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

Light reaction Differences Dark reactionYes Light energy required No

Grana Site of reaction Stroma

Water, Carbon dioxide,chlorophyll, light energy

Substances required forreaction

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 anddevelopment 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,

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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

(e)

11 (a) (i) P : Kwashiorkor

Q : Obesity

Rate of

Photo-

synthesis

Concentration of carbon dioxide

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(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 cows stomach has 4

compartments.

Cellulose digestion starts at the cows stomach, but for human, it starts in

the colon.

(b) i. Reticulum, rumen omasum, abomasums

ii The abomasums is the ruminants 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

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(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

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-the presence of air spaces between the cells of the leaf

(e)

15 (a) (i) chloroplast

(ii)

(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

(d)

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

light

chlorophyll

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Essay question

.1.(a)(i)Nutrition of organism PF1 : Autotrophic / by photosynthesis

P1 : Synthesis its own food / glucose

Nutrition of organism QF2 : Heterotrophic / HolozoicP2 : Obtain its food source / organicsubstances from surrounding orproducer

1.(a)(ii) One SimilarityF1 : Alimentary canal of both Q and Rcontains bacteria / protozoa

P1 : To digest cellulose into glucose

F2 : Large surface areaP2 : To increase the rate of diffusion /absorption

F3 : Secretes extracellular enzymesP3 : To hydrolyse large food molecules

1.(a)(ii) : Four Differences

Fact Explanation

R : 4 stomach chambers

Q : 1 stomach chamber

Part of the stomach are

Used for cellulose digestion

R : Has small caecumQ : Has large caecum

Place where the bacteria digestcellulose

R : The bacteria in rumen/reticulum

Q : The bacteria in caecum

The bacteria secretes cellulaseenzyme

Fact Explanation

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R : The food that havebeen swallowed for the1st time are returnedto the mouth and thenre-swallowed for 2ndtime

Q : The 1st faeces are re-eaten for absorption

To complete the digestion /Absorption of glucose

1.(b) Cause and Suggestion :1. Constipation :- Insufficient amount of fibrous food- Eat more vegetables / fruit

2. Night blindness :- Insufficient of vitamin A- Eat more carrots / tomatoes

3. Anemia- Insufficient iron / ferum nutrient- Eat more spinach / chicken liver

(a) Photosynthesis : A process whereby agreen plant

2.(a) F1 - Produces glucose/ starch from carbondioxide and waterP2 - in the presence of chlorophyll andsunlight

2(b) The formation of starch in green plants

P1 - Chlorophyll absorbs light energy toproduce ATP/electrons

P2 - Photolysis of water produce H+ ionsand OH- ions

P3 H+ ion combines with electron to formhydrogen atom

P4 - Hydrogen and ATP will be used in thedark reaction

P5 - occurs in granaP6 - The process take place in the absence

of lightP7 - CO2 combines with hydrogen to form

glucoseP8 - Glucose molecules undergo condensation /

converted / store as starchP9 - Formation of glucose and starch is

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through a series of chemical reactionP10 - occurs in stroma2(c) The importance of photosynthesis for the balance of nature :

P1 - Absorbs CO2 from atmosphereP2 - Replaces oxygen in the atmosphereP3 - helps maintaining the percentage of

CO2 /O2 in the atmosphereHow air pollution may have an effect on photosynthesis and the balance natureP1-incomplete combustion of fossil fuels produces tiny carbon particles whichform smoke,haze and smogP2-Smoke particles can also deposit on leaves and prevent gases exchange.P3-Both can lower the rate f photosynthesis

3. (a) A saprophyte is an organism that obtains its energy from the deaddecaying organicmatter. [1]

Many bacteria and fungi are saprotrophs [1] Examples are Rhizopus, Mucorand mushroom [1] The importance lies in their role as decomposers [1] They break down complex organic substances into simple substancesand help to release and recycle of certain elements such as carbon,nitrogen, sulphur and phosphorus [1] Their saprophytic activities prevent accumulation of dead bodies ofplants and animals [1]

They are important in the decomposition of sewage [1] Yeast is important in baking and brewing [1] Some saprophytes, for example Penicilliumare used in the manufactureof antibiotics [1] They are used in the producttion of yoghurt and cheese [1] As a food source, for example, edible mushrooms [1] Yeast is used in the production of vitamin B [1]

(b) A parasite is an organism that obtains its food from its living host Ectoparasites live on the outer surface of a host [1] Endoparasites live within a host [1] The parasites may harm the hosts. Examples are:

the tapeworm Taeniaobtains its nourishment from digested food in thehuman (host) intestine [1] hair louse sucks blood from the animal host [1]

(c)Similarities

Both saprophytes and parasites are heterotrophs [1] Both absorb soluble food materials [1]

Differences In parasites, the energy from food is derived from living organisms.Saprophytes obtainenergy from food derived from dead, decaying organic matter. [1]

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Parasites are more specific to their hosts. Saprophytes can grow on a variety ofdeadorganisms. [1]

Paper31.

2. Objective:To determine the vitamin C content in different fruit juice

Problem statement:Do different types of fruit juices contain similar amounts of vitamin C?

Hypothesis:

Lime juice contains a higher concentration of vitamin C compared to pineapple juice and

orange juice

Variables:

Manipulated variable: Types of fruit juice

Responding variable: Volume of fruit juice needed to decolorize the 1 ml DCIPP

solution/ % of

vitamin C

Fixed variable: Volume of DCIPP solution

Materials:DCIPP solution, o.1 % ascorbic acid solution, freshly prepared lime juice, pineapple juice

and orange juice

Apparatus:Specimen tubes, a syringe ( 1 ml ), syringes ( 5 ml ) with needles, beakers ( 50 ml ),

gauze cloth and a knife

Technique:

To record the volume of fruit juice needed to decolorize the 1 ml DCIPP using a scaled

syringe

Procedure:1. Four specimen tubes are labelled as ascorbic acid, lime juice , orange juice and

pineapple juice

2. 1 ml of DCIPP solution is placed in each specimen tube

3. A syringe is filled with 5 ml of ascorbic acid solution

4. The needle of the syringe is immersed in the DCIPP solution

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5. The ascorbic solution is added drop by drop to the DCIPP solution and the tube is

shaken slowly

6. The amount of ascorbic acid solution use to decolorize the DCIPP solution is

recorded

7. Steps 2 to 6 are repeated using lime juice, orange juice and pineapple juice

8. The percentage and concentration of vitamin C in the fruit juices are calculated

9. The data collected is recorded in a table

Results:

Solution Initialvolume (ml)

Finalvolume (ml)

Volumeused (ml)

Percentageof vitamin C

(%)

Concentrationof vitamin C

(mg/ml)

Ascorbic

acid

5.0 4.0 1.0 - -

Lime juice 5.0 2.5 2.5 1/1.25 x 0.1

= 0.04

0.4

Pineapple

juice

5.0 1.4 3.6 1/3.6x 0.1 =

0.03

0.3

Orange juice 5.0

Calculation:Percentage of vitamin C = Volume of 0.1 % ascorbic acid solution x 0.1

Volume of fruit juice

Concentration of vitamin C = Volume of 0.1 % ascorbic acid solution

Volume of fruit juice

a) Percentage of vitamin C in lime juice = 1/2.5 x o.1 = 0.o4

Concentration of vitamin C in lime juice = 1/ 2.5 = 0.4 mg / ml

Conclusion:The lime juice contain more vitamin C than pineapple juice and orange juice

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