Nutrients

Question 1

What is the definition of nutrients?

Answer 1

They are chemical substances in food that provide energy and materials needed by the body.

Question 2

What are the main nutrients group we learn?

Answer 2

Carbohydrate, proteins, fats and water

Question 3

What is the function of water for animals?

Answer 3

1) It is a solvent/medium where chemical reactions takes place
2) It is an essential component of protoplasm in cells
3) It is a key component in tissue fluids, digestive juices and blood
4) It helps control body temperature
5) It helps transport dissolved substances around the body.

Question 4

What is the function of water in plants?

Answer 4

1) It is essential for photosynthesis
2) It is needed to keep cells turgid
3) It is needed to transport mineral salts up the plant through the xylem.
4) It is needed to transport food substances from the leaves to all parts of the plant through the phloem.

Question 5

How is water being lost?

Answer 5

Through breathing, sweating and urinating.

Question 6

What are the organic compounds that make up carbohydrates?

Answer 6

Carbon, Oxygen and hydrogen

Question 7

What is the general formula for carbohydrates?

Answer 7

CnH2mOm

Example: Glucose –> C6H12O6

Question 8

What is sucrose composed of? Description?

Answer 8

Glucose + Fructose
Sucrose is not found in mammals.
They are a common transport form of sugar in plants.
They are found in sweet fruits and sugar cane stems.

Question 9

What is maltose composed of? Description

Answer 9

Glucose + Glucose
Formed when starch is partially digested. (Starch -> Maltose -> Glucose)
Found in barley seeds which can be used during fermentation to produce beer.

Question 10

What is Lactose composed of? Description

Answer 10

Glucose + Galactose

Found in the milk of all mammals.

Question 11

What are organic compounds?

Answer 11

Compounds that are obtained from living organisms and contain carbon.

Question 12

General formula of carbohydrates?

Answer 12

CnH2mOm

Question 13

What are the 3 types of disaccharides?

Answer 13

Galactose (milk sugar), fructose (fruit sugar) and glucose

Question 14

Which monosaccharide is the most readily transported?

Answer 14

Glucose. It is easily metabolised when needed.

Question 15

How are disaccharides formed?

Answer 15

They are formed during condensation reactions whereby 2 simple sugars are combined together with the loss of one water molecule.

Question 16

What are carbohydrates?

Answer 16

They are the chief source of energy for all bodily functions and muscular exertion as they contain many C-H bonds. They are also known as organic compounds.

Question 17

Functions of carbohydrates?

Answer 17

1) Act as a substrate for respiration, provide energy for cell activites.
2) They are able to form supporting structures for the cell. For instance, cellulose in the cell walls of plants.
3) They can be converted into amino acids and fats when there are excess carbohydrates. Some may be used to form nucleic acids.
4) Used to produce nectar in flowers

Question 18

Where are glucose and glycogen stored in the human body?

Answer 18

They are stored in the Liver and Muscles.

Question 19

What gives rise to different chemical and biological properties in simple sugars?

Answer 19

The arrangement of atoms in the molecule.

Question 20

Why does glucose circulate in the blood of the human body?

Answer 20

Glucose is most readily transported in the bodies of organisms. They can be easily metabolized when needed.

Question 21

What is the term used for the result of the combination of 2 simple sugars?

Answer 21

Disaccharides. They consist of 2 monosaccharides chemically bonded.

Question 22

The chemical formula for Disaccharides?

Answer 22

C12H22O11

Question 23

How are disaccharides formed?

Answer 23

They are formed during condensation reactions whereby 2 simple sugars are combined together with the loss of one water molecule.

Question 24

Can monosaccharides pass through PPM?

Answer 24

Yes they can

Question 25

Where can Maltose be found?

Answer 25

They are found in malt, from wheat.

Question 26

Describe hydrolytic reaction/ hydrolysis?

Answer 26

It is a process where a water molecule is added to the disaccharide, and they are being split by treating them with acid or a suitable enzyme.

Question 27

What are polysaccharides?

Answer 27

They are carbohydrates that consist of monosaccharide sugar subunits joined together in a long chain.

Question 28

What is the process called when monosaccharides join together in a long chain?

Answer 28

It is called polymerisation.

Question 29

The function of starch?

Answer 29

A storage form of carbohydrates in plants. | It is found in storage organs of plants. (chloroplast)

Question 30

Function of glycogen?

Answer 30

A storage form of carbohydrates in mammals. | Digested to form glucose when needed.

Question 31

Why are glycogen often found in the liver and muscle?

Answer 31

Glycogen plays an important role in keeping our muscles fuelled for exercise. When we exercise, our muscles will take advantage of their stored glycogen. Glucose in our blood and glycogen stored in the liver can also be used to keep our muscles fuelled.

Question 32

The function of cellulose?

Answer 32

Cellulose cell walls protect plant cells. | Serve as a dietary fiber to prevent constipation.

Question 33

Describe Benedict's test?

Answer 33

1) Add 2cm3 Benedict solution and 2cm3 food sample in the test tube. 2) Shake the mixture 3) Heat the content in a boiling water bath for 5 minutes. 4) If reducing sugar is present, then the mixture would appear as a brick-red precipitate. If reducing sugar is absent, then it would remain blue in color.

Question 34

Describe the iodine test?

Answer 34

1) Add 2cm3 of food sample to clean test tube. 2) Add a few drops of iodine solution to test tube. 3) If starch is present, the iodine solution turns from yellowish-brown to blue-black. If starch is not present, the iodine solution remains yellowish brown.

Question 35

What is the difference between fats and carbohydrates?

Answer 35

1) Fats contain lesson number of oxygen atoms in proportion to hydrogen atoms, whereas carbohydrates contain more oxygen atoms than hydrogen atoms. 2) fats have no generalized formula as the elements present in fats do not occur in definite proportions.

Question 36

What are fats?

Answer 36

They are organic molecules consisting of carbon, hydrogen and oxygen.

Question 37

What is the simplest form of fats?

Answer 37

Triglycerides. [3 fatty acids + 1 glycerol]

Question 38

What are the functions of fats?

Answer 38

1) Long term energy storage. 2) Insulating material that prevents excessive heat loss 3) Solvent for fat-soluble vitamins 4) Essential part of cell protoplasm 50 Reduce water loss from skin surface