Nutrition

Question 1

Give three examples of a macronutrient.

Answer 1

Carbohydrates, fats, protein.

Question 2

Give three examples of a micronutrient.

Answer 2

Vitamins, essential fatty acids, minerals.

Question 3

What is the main usage of macronutrients?

Answer 3

Sources of energy and ‘building blocks’.

Question 4

Give the SI unit of energy.

Answer 4

Joules

Question 5

Approximately how many kcal’s would a 70kg adult human male with a mainly sedentary life style require per day?

Answer 5

2500 kcal per day.

Question 6

Name three monosaccharides that are extremely common in the human diet.

Answer 6

Glucose, fructose, mannose.

Question 7

Name two disaccharides.

Answer 7

Sucrose, lactose.

Question 8

Name three polysaccharides.

Answer 8

Starch, glycogen, dietary fibre.

Question 9

Give the name of starch in its unbranched form.

Answer 9

Amylose.

Question 10

Give the name of starch in its branched form.

Answer 10

Amylopectin.

Question 11

Name the type of linkages in amylose/amylopectin monomers, and the type of linkages which form branch points.

Answer 11

alpha-I,4 - monomers

alpha-I,6 - branch points

Question 12

Define fibre.

Answer 12

Non-digestible carbohydrate.

Question 13

Describe the glucose structure found within cellulose (plant cell walls).

Answer 13

Glucose in long unbranched chains, monomers are linked by beta-I,4 linkages (note difference to amylopectin).

Question 14

Describe the structure of a hemicellulose.

Answer 14

Main constituent of cereal fibres. Branches structures composed of pentoses/hexoses and there uronic acids. May be soluble/insoluble.

Question 15

What are pectins?

Answer 15

Insoluble complex polysaccharides.

Question 16

What are gums?

Answer 16

Soluble complex polysaccharides.

Question 17

What are lignins?

Answer 17

Non-polysaccharide woody polymers of aromatic alcohols.

Question 18

Where and how are hemicelluloses/pectins broken down?

Answer 18

Fermented by bacteria in the large intestine, broken into short chain fatty acids (BUTYRATE) and hydrogen/methane/hydrogen sulphide gases.

Question 19

State three reasons why dietary fibre is beneficial.

Answer 19

Lowers blood cholesteral levels (soluble fibre).
Slows starch breakdown/delays glucose absorption.
Improves large intestine health/prevents colon cancer.

Question 20

Give one downside of dietary fibre.

Answer 20

Fermentation during breakdown releases gas, can cause discomfort.

Question 21

Name the carbohydrate in milk.

Answer 21

Lactose - disaccharide of galactose and glucose.

Question 22

Which type of milk contains less lactose; cow or human?

Answer 22

Cow.

Question 23

When used for feeding infants, what is cow’s milk supplemented with and why?

Answer 23

Sucrose - cow’s milk contains less lactose than human milk does.

Question 24

What does the enzyme LACTASE convert LACTOSE into?

Answer 24

Galactose and glucose.

Question 25

In lactose intolerence, which enzyme ceases to be secreted?

Answer 25

Lactase - very frequent phenotype in Asians.

Question 26

What is GALACTOSAEMIA?

Answer 26

Rare inherited disorder of galactose metabolism (1 in 100,000 people). A galactose metabolite is deposited in the LIVER & BRAIN, leads to MENTAL DEFICIENCY. Disorder may be fatal, requires lactose-free diet from birth.