Ch4 - Food & digestion

Question 1

What elements does carbohydrates contain

Answer 1

Carbon
Hydrogen
Oxygen

Question 2

How much of the mass of the human body does carbohydrates make up and what is the purpose

Answer 2

5%

They are the bodies main fuel for supplying cells with energy

Question 3

How do you cells release the energy carbohydrates give them

Answer 3

They oxidise of sugar called glucose in a process called respiration

Question 4

What is the main sugar that is transported through plant stems

Answer 4

Sucrose

Question 5

Explain why sugar in our diet cause of sugar decay

Answer 5

Bacteria in our mouths feed on the sugar, break it down and produces acid is that decay our tooth enamel
It then penetrates the softer dentine below, causing a cavity and hits the nerve

Question 6

Where do most cops come from

Answer 6

Starch, not sugars

Question 7

Is starch soluble or insoluble

Answer 7

It is a large, insoluble molecules. Because of this starch is found as a storage carbohydrate implants

Question 8

What is starch made up of

Answer 8

Long chains of hundreds of glucose molecules joined together. It is a polymer of glucose

Question 9

Where is starch found?

Answer 9

Only in plant tissues!

In animals some of them contain a similar carbohydrate called glucagon.

Question 10

Where is glycogen found

Answer 10

In tissues like the liver, muscles etc where it acts as a store of energy for these organs.
It is also a polymer of glucose

Question 11

Why do large carbohydrates like starch and Glucagon have to be broken down into simple sugars in digestion

Answer 11

So it can be absorbed into the blood

Question 12

What do plants make their cell wall with

Answer 12

Cellulose, another carb that is a polymer of glucose.

Question 13

What elements do lipids contain

Answer 13

Carbon
Hydrogen
Oxygen
(The same as carbohydrates, but the oxygen proportion in a lipid is much lower)

Question 14

Roughly how much do lipids make up of the mass of our body, and what do they do

Answer 14

10%
Form an essential part of the structure of all cells, and fat is the deposited in certain parts of the body as a long-term store of energy

Question 15

What is fat used as

Answer 15

• Fat under the skin acts as insulation reducing heat loss through the surface of the body
• Fat around or organs such as kidney also helps to protect them from mechanical damage

Question 16

What are the chemical building blocks of lipids

Answer 16

The two molecules:

• Glycerol (a.k.a. Glycerine)
• Fatty acids

Question 17

How much to proteins make up of the mass of our bodies

Answer 17

18%

Question 18

What is protein used for

Answer 18

The growth and a pair of our tissues

Question 19

What are enzymes made of

Answer 19

Proteins

Question 20

What is the protein deficiency called

Answer 20

Kwashiorkor

Swollen belly caused by fluid collecting in tissues loss of weight, poor muscle growth and flaky skin

Question 21

What is an amino acid

Answer 21

Are polymer made from 20 different subunits. 
They all contain for chemical elements:
-Carbon
-Hydrogen
-Oxygen
-Nitrogen

Question 22

What is calcium used for and give some examples of foods rich in it

Answer 22

• Making bones and teeth

- Dairy products, fish, bread

Question 23

What is phosphorus used for and give some examples of foods rich in it

Answer 23

• Making teeth and bones; parts of many chemicals e.g. DNA

- Most foods

Question 24

What is the use of sodium and give some examples of food rich in it

Answer 24

• In bodily fluids e.g. blood

- Common salt, most foods

Question 25

What is chlorine used for and give some examples of foods rich in it

Answer 25

- In bodily fluid is e.g. blood | - Common salt, most foods

Question 26

What is the use of magnesium and give some examples if food rich in it

Answer 26

- Making bones: found inside cells | - Green vegetables

Question 27

What is the use of iron and give some examples of foods rich in it

Answer 27

- Parts of haemoglobin, helps carry oxygen | - Red meats, liver, eggs

Question 28

What is the use of vitamin A in the body, what is the deficiency and what are some foods that are a good source of it

Answer 28

- Making a chemical in the retina; also protects the surface of the eye - Night blindness, damaged cornea of the eye - Fish liver oils, liver, butter, margarine

Question 29

What is the use of vitamin B1 in the body, what is the deficiency and what are some foods that are a good source of it

Answer 29

- Helps with cell respiration - Beri-beri - Yeast extract, cereals

Question 30

What is the use of vitamin B2 in the body, what is the deficiency and what are some foods that are a good source of it

Answer 30

- Helps with cell respiration - Poor growth, dry skin - Green vegetables, eggs, fish

Question 31

What is the use of vitamin B3 in the body, what is the deficiency and what are some foods that are a good source of it

Answer 31

- Helps with cell respiration - Pellagra (dry red skin, poor growth and digestive disorders) - Liver, meat, fish

Question 32

What is the use of vitamin C in the body, what is the deficiency and what are some foods that are a good source of it

Answer 32

- Sticks together cells lining surfaces such as the mouth - Scurvy - Fresh fruit and vegetables

Question 33

What is the use of vitamin D in the body, what is the deficiency and what are some foods that are a good source of it

Answer 33

- Helps bones absorb calcium and phosphate - Ricketts, poor teeth - Fish liver oils; also made on skin in sunlight

Question 34

How do you test for glucose?

Answer 34

- Add Benedicks solution to the solution (blue) - Heat/bring to boil in a water bath - Solution turns to a cloudy orange or brick red precipitate of copper (1) oxide

Question 35

How do you test for starch

Answer 35

-Add a drop of dilute iodine solution -This turns from brown to dark blue Note, starch is insoluble

Question 36

How to measure the energy content of food

Answer 36

- Find the mass of all food - Put 20 cm³ of water in a boiling tube, support it in a clamp stand. Measure the temperature of the water. - Spear the food on the end of the mounted needle - Hold on a Bunsen burner till it catches light - Hold it (once and fire) underneath the boiling tube. This continues, relighting if necessary, until it will no longer burn. - Measure the final temperature of the water. Stir with the thermometer to ensure the heat evenly distributed

Question 37

What is the equation for energy

Answer 37

Energy in joules per gram (J/G) = ((final temperature - temperature at start) x 20 g x 4.2 (J/C)) / mass of food

Question 38

Define digestion

Answer 38

The chemical and mechanical breakdown of food. It converts large insoluble molecules into small soluble molecules, which can be absorbed into the blood

Question 39

How does digestant occur in the mouth, stomach and duodenum

Answer 39

Breakdown of food using enzymes from the gut wall or glands

Question 40

What happens in the ileum

Answer 40

Absorbs the digested food

Question 41

What happens in the large intestine

Answer 41

- Absorbing water out of the remains | - Storing waste products (faeces)

Question 42

What are the three main classes of foods that are broken down by enzymes

Answer 42

-Carbohydrates are digestives by carboghydrases - proteins are acted upon by proteases - lipids are broken down by lipase Saliva helps moisten food and contains the enzyme amylase which starts the breakdown of starch

Question 43

What does the stomach wall secrete

Answer 43

Hydrochloric acid to kill the bacteria that are taken into the got along with the food, helping protect us from food poisoning

Question 44

Why are the bile and pancreatic juices alkaline

Answer 44

To neutralise the mixture of semi digestive food and enzymes that come out of the stomach that are acidic

Question 45

What is an adaptation in the ileum

Answer 45

It has a high surface area to absorb the digestive food - The length of the intestine helps provide a large surface area and this is aided by folds in the lining. - The greatest increase is due to tiny project and is in aligning called villi

Question 46

What is the function of the first part of the large intestine (colon)

Answer 46

Absorbed most of the remaining water from the contents, leaving a semisolid waste material called faeces

Question 47

Our body must contain these 5 to be healthy and work properly

Answer 47

-Carbohydrates -Lipids -Proteins -Minerals -Vitamins (And fibre and water)