chapter 14 : human digestive system

Question 1

why do we eat?

Answer 1

because food provides the nutrients to the body needs to carry out cellular activities

Question 2

what is one of a cellular activity?

Answer 2

respiration, through which energy is released to carry out processes such as growth and tissue repair

Question 3

food contains different types of nutrients

what are three common types of nutrients found in food?

Answer 3

• carbohydrate
• Proteins
• Fats

Question 4

what are examples of food containing carbohydrates?

Answer 4

• Rice
• Potatoes
• bread
• Noodles
• Biscuit
• Pasta

Question 5

examples of food containing proteins?

Answer 5

• Beans
• peas
• tofu
• eggs
• fish
• milk

Question 6

examples of food containing fats?

Answer 6

• tuna
• cooking oil
• peanuts
• avocado

Question 7

why do food needs to be broken down?

Answer 7

so that nutrients in it can be absorbed by the body and used by the body cells.

Question 7

describe the human digestive system

Answer 7

• it is a 9 m long muscular tube which starts from the mouth and ends at the anud
• As food move down the digestive tract it is broken down into small soluble molecules by a combination of physical and chemical processes

Question 7

explain the physical process of digestion

Answer 7

Who is broken down into smaller pieces by physical for mechanical means such as crushing, grinding and mixing

Question 8

describe the chemical process of digestion

Answer 8

food is broken down into smaller molecules to the action of biological molecules known as enzymes

Question 9

what are enzymes?

Answer 9

• They are biological molecules produced by the digestive system which speed up the breakdown of large put molecules
  into small molecules
• without enzymes most chemical reactions to take too much time to complete

Question 10

enzymes are specific, they only act on one type of substance

what are the three common classes of enzymes in the human digestive system?

Answer 10

• carbohydrases, which speed up the breakdown of carbohydrates into simple sugars
• proteases, which speed up the breakdown of proteins into amino acids
• Lipases, which speed up the breakdown of fats (or lipids) into fatty acids and glycerol

Question 11

what happens in the mouth?

Answer 11

• physical digestion/ mechanical digestion : strong teeth and your muscles in the mouth cut and crushed the food into smaller pieces
• chemical digestion: contains carbohydrases. Partial digestions of starch, a type of carbohydrate begins in the mouth.
• other functions : saliva softens and lubricates the food for easier swallowing

Question 12

what happens in the gullet?

Answer 12

• physical digestion : none
• chemical digestion : The colour does not release any digestive juice however starch from the mouth continues to be digestant by carbohydrases that are mixed with the food.
• other function : the muscles of the garlic push the food towards the stomach

Question 13

what happens in the stomach

Answer 13

• physical digestion: The stomach churns food into smaller pieces
• Chemical digestion : the stomach releases gastric juice that contains proteases to digest proteins.
• other functions : The stomach releases gastric juice containing hydrophilic acid which kills harmful microorganisms and provides the right conditions for proteases to act,
• It has to take layer of mucus to protect its tissues from damage caused by the hydrochloric acid and proteases in the gastric juice, The muscles at both ends of the stomach control the food entering and leaving the stomach

Question 14

what happens in the small intestine?

Answer 14

Physical Digestion: None
Chemical digestion : The small intestine is the main site for chemical digestions you to numerous enzymes released, That’s our first digestant here due to the presence of Lipases in the digestive Juices.
carbohydrates, Proteins and fats are you fully digested here

Question 15

what happens in the large intestine

Answer 15

some of the remaining water and mineral salt in the food are absorbed here

Question 15

what happens in the rectum?

Answer 15

indigestible food and waste a form faeces, which is temporarily stored here before it leaves the body

Question 16

what happens at the anus

Answer 16

faeces is released through this opening

Question 17

what our the end products of digestion?

Answer 17

they are soluble molecules of digestive food that are small enough to be absorbed into the blood

Question 18

what are the benefits of simple sugars amino acids and fatty acids

Answer 18

• cells use simple sugars during respiration to release energy which allows cell to carry out their functions and enable the body to grow
• Amino acid serve as raw materials for a tissue repair and cell growth
• Fatty acids and glycerol are used to make fats in the body

Question 19

what are your symptoms of people who have diabetes

Answer 19

• Frequent urination
• Constant hunger
• Blurred vision
• Unexplained weight loss
• Tingling or numbness in the hands and
• Slow healing of wounds

Question 19

what is diabetes?

Answer 19

disease in which the level of sugar in the blood or blood sugar level is too high

Question 20

what is constipation?

Answer 20

when one has constipation the faeces move through the large intestines very slowly resulting in too much water being absorbed from the faeces into the large intestines. The Faeces thus becomes hard and dry

Question 21

what is gastric pain?

Answer 21

• The most common cause of the gastric pain is gastrities, which is the painful swelling or inflammation of the stomach lining and it may be cost by a bacterial or viral infection

Question 22

what is food poisoning?

Answer 22

• some bacteria can cause life-threatening diseases such as cholera and salmonella infection due to proper sanitation and hygiene such diseases are not common in Singapore

Question 24

benefits of bacteria

what are some benefits of bacteria

Answer 24

• ## because of bacteria, we can fight of certain diseases absorb nutrients and mineral salts and produce certain enzymes

Question 25

examples of food items that are produced using bacteria

Answer 25

Coffee chocolate yoghurt cheese vinegar pickles miso sourdough bread and belacan.