Biology: Biological Molecules and Food Tests

Question 1

Define carbohydrates

Answer 1

Sugar molecules that are made up of Carbon, Hydrogen and Oxygen; their ratio being 1:2:1 respectively.

Question 2

Define Lipids

Answer 2

Oil and fat molecules made up of glycerol and three fatty acids each.

Question 3

Define Proteins

Answer 3

Specifically shaped chains of amino acids that contain Carbon, Hydrogen, Oxygen, Nitrogen and sometimes Sulfur.

Question 4

Test for Glucose

Answer 4

Benedict’s test:
- Benedict’s solution is blue
- Turns red in presence of glucose at 75ºC (yellow or green at lower concentrations)

Question 5

Test for Starch

Answer 5

Iodine solution test:
- Iodine solution is orange-black
- Turns blue-black in presence of starch

Question 6

Test for Lipids

Answer 6

Sudan III test:
- Sudan III solution is bright red
- In presence of lipids it will react with them and create a bright red layer on top of the mixture

Question 7

Test for Proteins

Answer 7

Biuret test:
-Biuret solution is blue
-Turns purple or pink in presence of protein

Question 8

Function of Carbohydrates

Answer 8

Provide energy

Question 9

Function of Lipids

Answer 9

Serve as an energy store and provide it, create insulation

Question 10

Function of Proteins

Answer 10

Provide amino acids which are used to create and repair tissue.

Question 11

Function of Vitamins

Answer 11

-A: Improve vision, keep healthy skin and hair
-C: Prevents scurvy
-D: Required in calcium absorption

Question 12

Calcium and Sulfur

Answer 12

Make bones and teeth

Question 13

Iron

Answer 13

Needed to make haemoglobin in the blood

Question 14

Water

Answer 14

Used in every bodily function

Question 15

Fibres

Answer 15

Lubricates food in the intestines, making it easier to move (can’t be digested)

Question 16

What are some dietary requirement variation causes between people?

Answer 16

-Age
-Activity level
-Size
-Pregnancy status
-Allergies/health related dietary needs

Question 17

Starch gets broken down by ____ into ____

Answer 17

Amylase
Maltose

Question 18

Maltose gets broken down by ____ into ____

Answer 18

Maltase
Glucose

Question 19

Proteins get broken down by ____ into ____

Answer 19

Protease
Amino acids

Question 20

Lipids get broken down by ____ into ____

Answer 20

Lipase
Glycerol and Fatty acids

Question 21

Bile

Answer 21

A fluid that is made in the Liver and stored in the gallbladder, it is released into the duodenum. It neutralises stomach acid (pH2 to pH7) and emulsifies chunks of lipids.

Question 22

Bolus

Answer 22

A bolus is a mixture between ingested food and saliva that goes down the oesophagus through peristalsis.

Question 23

Function of the mouth

Answer 23

Mechanically and chemically break down food

Question 24

Function of the oesophagus

Answer 24

Transport food boli down into the stomach through peristalsis

Question 25

Function of stomach

Answer 25

-Pummel food with muscular walls
-Produces pepsin (protease enzyme)
-Produces HCl (kills bacteria, allows pepsin to function)

Question 26

Function of liver (in digestion)

Answer 26

Produces bile

Question 27

Function of gallbladder

Answer 27

Stores bile

Question 28

Function of pancreas

Answer 28

Produces amylase, lipase and protease enzymes; Releases them into the duodenum

Question 29

Duodenum (small intestine)

Answer 29

Releases bile to neutralise stomach acid and emulsify lipid chunks

Question 30

Ileum (small intestine)

Answer 30

Absorbs any remaining nutrients

Question 31

Colon (large intestine)

Answer 31

Absorbs any excess water to be released in urine

Question 32

Rectum

Answer 32

Stores any remaining indigestible waste and excretes it.