Digestive System Quiz

Question 1

What are the three main biological molecules we eat?

Answer 1

Carbohydrates, lipids and proteins

Question 2

What are carbs the source of?

Answer 2

All energy that we have available

Question 3

What are the simplest sugars called?

Answer 3

Monosaccharides (glucose, fructose)

Question 4

What is sucrose?

Answer 4

Disaccharide (made of two monosaccharides)

Sucrose made of glucose and fructose

Question 5

What are the two roles of polysaccharides?

Answer 5

Store energy (like amylose)

Storing energy as structures (cellulose)

Question 6

What is the source of all carbs?

Answer 6

The sun

Question 7

What can’t lipids dissolve in?

Answer 7

Water

Question 8

What are lipids made of?

Answer 8

Glycerol and 3 fatty acids

Question 9

What is the difference between saturated and unsaturated fats?

Answer 9

Saturated: all bonds are single bonds with hydrogen

Unsaturated: can have double bonds or triple bonds

Question 10

What roles do proteins play in the body?

Answer 10

Affects antibodies, enzymes and hormones

Question 11

What are proteins made of?

Answer 11

Amino acids

Question 12

What are polypeptides?

Answer 12

Long chains of amino acids

Question 13

What are essential amino acids?

Answer 13

The 9 amino acids our body can’t make on its own

Question 14

Where do we get energy? Where do we store it? (6)

Answer 14

• from good we eat
• sugars (carbs) are broken down into energy through cellular respiration
• don’t use all energy produced every day so it’s stored as glycogen (glucose polymer)
• found in liver and muscle cells (use it first)
• stores as fat is glycogen is full and energy is still being produced
• when fewer calories are being produced than are being burned, fuel is taken out of glycogen and digested

Question 15

Explain how to get proteins if on a vegetarian diet?

Answer 15

Need to make sure you’re still getting enough protein

Out of 20 amino acids, 8 must be eaten

• grains (like corn) have 6 but are missing 2
• beans have 6 but are missing a different 2

Question 16

What happens if you’re missing too much of a nutrient?

Answer 16

A deficiency disease like scurvy (vitamin c) rickets (vitamin D) anemia (iron or B12)

Question 17

What does digestion of cellulose have to do with diet?

Answer 17

Cellulose is more difficult to digest so that governs the life strategies of herbivores but you need sugars which you can get from cellulose

Cows digest cellulose well so there’s no need for supplemental sugars

Gorillas need other sugars because they can’t digest cellulose

Question 18

What are the differences of teeth in different diets? What about the length of the digestive system? Why are these different?

Answer 18

Carnivore: teeth are sharp and ripping; short system (protein is easier to digest)

Herbivore: wide grinding teeth; longer system (more time to digest cellulose; symbiotic bacteria in gut which helps digest cellulose)

Omnivores: have combinations of both

Question 19

What are the functions of the digestive system?

Answer 19

1. Ingest (take in nutrients)
2. Digest (break down organic molecules into smaller pieces)
3. Absorb (take digested molecules into cells and transport to body and tissues)
4. Egest (remove waste materials from body)

Question 20

What are the processes of digestion?

Answer 20

Mechanical digestion- the breakdown of food into smaller parts (chewing)

Chemical digestion- the breakdown of the food into chemical parts

Absorption- the body taking in the nutrients from food

Question 21

Describe the function of the tongue? (4)

Answer 21

• Positions food on teeth for chewing
• pushes food to back of mouth for swallowing
• the bolus (chewed food) passed into esophagus
• has cone shaped projections (papillae); house taste buds

Question 22

What role does saliva play in digestion? (4)

Answer 22

Produced by 3 glands (parotid, sublingual and submandibular glands)

Empty secretions into mouth through short ducts

Contains water, amylase and mucus

Lubricates food so it’s easy to swallow

Question 23

Explain more about the esophagus. (3)

Answer 23

• muscular tube connecting mouth and stomach
• transports food and mucus to stomach
• food moves through peristalsis (contractions in esophagus, small intestine, large intestine, and rectum)

Question 24

Explain the role of the stomach. (3)

Answer 24

• muscular bag that stretches as it fills with food
• 3 sets of muscles contract rhythmically the mix food with gastric juices produced in stomach (juices contain HCl which turns pepsinogen into pepsin which digests most proteins)
• mechanical and chemical digestion

Question 25

Explain the role of the small intestine. (3)

Answer 25

• Majority of digestion occurs in first 25 cm (duodenum)
• entire thing is 7m long, with other parts being jejunum and ileum
• ball of food that leaves stomach (chyme) has stomach acid which causes production of secretin (hormone) which triggers pancreas to release bicarbonate ions to reduce Ph and not damage intestine

Question 26

Explain the role of the large intestine. (2)

Answer 26

• about 5cm wide and 1.5m long

* store waste materials long enough that water can be reabsorbed back into the body

Question 27

Describe egestion. (3)

Answer 27

• cellulose can’t be egested so it is most of what is egested
• bowel movements allow potentially toxic waste to be removed
• those who don’t eat enough cellulose can develop colon cancer from toxic waste build up

Question 28

Explain the purpose and complications from the liver.

Answer 28

• produces bile which helps break down food in the stomach
• detoxifies substances from the body
• stores vitamin A, B12 and D

Problems: jaundice, cirrhosis

Question 29

Explain more about the gallbladder.

Answer 29

Stores bile

Needed when stomach is empty and digestion isn’t occurring

Problems: gallstones

Question 30

Describe the purpose of the pancreas.

Answer 30

Produces insulin (regulates sugar concentration in the blood)

Produces digestive enzymes (trypsin)