Materia: Biology Senior 3

Profesora: Ma. Magdalena Ravagnan

Contenido nodal: Nutrition and transport in humans

SEGUNDO TRIMESTRE

Fecha de presentación: February 2014

A- Enzymes

1) i- Complete the table:

SUBSTRATE ENZYME PRODUCT

Starch

Protease

Fatty acids + glycerol

ii- Explain what happens to the activity of an enzyme when it is boiled.

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B- Human nutrition

1) (a) Fibre in the human diet contains a lot of cellulose that humans cannot digest.

(i) State two advantages to humans of including fibre in the diet.

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2……………………………………………………………………………………………………………………………

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(b) Micronutrients are components of the diet that are only needed in very small quantities.

Name two micronutrients that are essential for the healthy development of bones and teeth.

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2 ………………………………………………..[2]

2) Complete the following table:

3) Fig. 3.1 shows a section through a villus in the small intestine. The blood capillaries are not shown.

(a) (i) On Fig. 3.1, draw a capillary inside the villus and link it with the appropriate blood vessels. Draw an arrow to show

the direction of blood flow in the capillary.

(ii) Name the first organ to which blood flows from the small intestine.

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(b) The cells of the surface layer of the villus are involved in absorption.

State two features of these cells that improve absorption.

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2. ..............................................................................................................................................................

(c) (i) Name structure Y. .................................................................................................