Ch.6 Nutrition in humans

Question 1

________ is a process in which organisms obtain food for energy, growth and maintaining health.

Answer 1

Nutrition

Question 2

A__________ nutrition and h___________ nutrition are two different modes of nutrition.

Answer 2

autotrophic (自養) ; heterotrophic (異養)

Question 3

Plants make their own food by photosynthesis. They are _________s.

Answer 3

autotrophs (自養生物)

Question 4

Most of the organisms cannot make their own food but depend on other organisms for food. They are __________s.

Answer 4

heterotrophs (異養生物)

Question 5

There are three types of heterotrophic nutrition, including h_______ nutrition, s__________ nutrition and p_______ nutrition.

Answer 5

holozoic(動物式); saprophytic(腐生式); parasitic(寄生式)

Question 6

In holozoic nutrition, organisms take in _______ food and digest it inside the body.
E.g.: Humans

Answer 6

complex

Question 7

In saprophytic nutrition, organisms break down the food outside the body and then _______ the soluble nutrients into the body.
E.g.: saprophytes like bread mould and bacteria

Answer 7

absorb

Question 8

In ________ nutrition, organisms live on or inside the body of other organisms and obtain food from them.
E.g.: parasites like tapeworms

Answer 8

parasitic

Question 9

The membrane of human cells is __________ permeable. Large, complex food molecules have to be broken down into small, soluble molecules to enter the cells.

Answer 9

differentially

Question 10

The food molecules are ________ly different from those making up our body. Our body has to break down and use the small molecules to build our own molecules.

Answer 10

structurally

Question 11

Processes of nutrition in humans:

________ → digestion → _________ → __________ → egestion

Answer 11

ingestion; absorption; assimilation(同化)

Question 12

Nutrition in humans take place in the digestive system, which consist of the _________ canal and its associated digestive ______.

Answer 12

alimentary; glands

Question 13

The alimentary canal is a long muscular tube that begins at the ______ and ends at the _____.

Answer 13

mouth; anus(肛門)

Question 14

The digestive glands produce ________ ______, which are released into the alimentary canal to aid digestion.

Answer 14

digestive juices (消化液)

Question 15

In which two forms does digestion occur?

Answer 15

Physical digestion and chemical digestion

Question 16

_________ digestion breaks down food into smaller pieces by physical actions.

Answer 16

Physical

Question 17

Physical digestion increases the ________ area of the food for digestive juices to act on.

Answer 17

surface

Question 18

Chemical digestion involves chemical reactions that are catalyzed by digestive ________s such as carbohydrases, lipases and proteases.

Answer 18

enzymes

Question 19

Chemical digestion breaks down complex food molecules into small, soluble forms, which are ready for __________.

Answer 19

absorption

Question 20

Name the physical digestion in the mouth cavity.

Answer 20

Chewing (mastication)

Question 21

The chemical digestion in the mouth cavity is catalyzed by the enzyme in _______.

Answer 21

saliva

Question 22

Name the physical digestion in the stomach.

Answer 22

Churning (劇烈攪動)

Question 23

The chemical digestion in the stomach is catalyzed by the enzyme in _______ juice.

Answer 23

gastric

Question 24

What is the physical digestion in the small intestine called and what catalyzes it?

Answer 24

Emulsification(乳化) by bile(膽汁)

Question 25

The chemical digestion in the small intestine is catalyzed by enzymes in __________ juice and enzymes on the intestinal _____.

Answer 25

pancreatic; wall

Question 26

Name the process of moving food from oesophagus to rectum.

Answer 26

Peristalsis (蠕動)

Question 27

In peristalsis, the circular muscles and longitudinal muscles in the wall of the alimentary canal _________ alternatively to produce a ______-like movement to push the food.

Answer 27

contract; wave

Question 28

Importance of peristalsis: - it pushes food along the alimentary canal - it helps mix the food with _________ juices - it helps ___________ by increasing the contact between the intestinal wall and digested food

Answer 28

digestive; absorption

Question 29

Site of digestion: mouth cavity Digestive juice: ______ Site of production: ________ glands

Answer 29

saliva; salivary

Question 30

Enzyme or other substance present in saliva: - salivary _________ [starch → maltose] - water - mucus

Answer 30

amylase

Question 31

Site of digestion: stomach Digestive juice: _______ juice Site of production: _______ glands in stomach wall

Answer 31

gastric; gastric

Question 32

Enzymes or other substances present in gastric juice: - pepsin [protein → ________s] - ____________ acid - mucus

Answer 32

peptides; hydrochloric

Question 33

Site of digestion: small intestine (duodenum) Digestive juice: bile Site of production: _____

Answer 33

liver

Question 34

Enzymes or other substances present in bile: - bile ____s [lipids → small lipid droplets] (emulsification) - bile pigments - sodium _________________

Answer 34

salts; hydrogencarbonate

Question 35

Where is the bile stored?

Answer 35

Gallbladder

Question 36

T/F: Emulsification is chemical digestion.

Answer 36

F | Emulsification is *physical* digestion.

Question 37

Site of digestion: [____?____] Digestive juice: pancreatic juice Site of production: pancreas

Answer 37

small intestine

Question 38

Enzymes or other substances present: - pancreatic amylase [starch → ________] - proteases [proteins → ________s → amino acids] - pancreatic _______ [lipids → glycerol + fatty acid] - sodium hydrogencarbonate

Answer 38

maltose; peptides; lipase

Question 39

Site of digestion: small intestine Digestive juice: _________ juice Site of production: ______s in the wall of small intestine

Answer 39

intestinal; glands; sodium

Question 40

Site of digestion: small intestine Digestion juice: intestinal juice Site of production: specialized cells on __________ of small intestine

Answer 40

epithelium

Question 41

Enzymes or other substances present in intestinal juice: - ____________s [disaccharides → monosaccharides] - _________s [peptides → amino acids] - water - mucus - sodium hydrogencarbonate

Answer 41

carbohydrate; proteases

Question 42

``` [Matching] A) saliva B) gastric juice C) bile D) pancreatic juice E) intestinal juice Acidic:________________ Alkaline:________________ Neutral:________________ ```

Answer 42

Acidic: B Alkaline: C, D, E Neutral: A

Question 43

Absorption of food mainly takes place in the ______ of the small intestine.

Answer 43

ileum

Question 44

There are numerous ___A___ in small intestine for absorption. On the epithelial cells of ___A___, there are numerous ___B___. What do A and B refer to?

Answer 44

villi; microvilli

Question 45

Each villus has a _______ vessel called lacteal in the centre. The lacteal is surrounded by a network of ________ies.

Answer 45

lymph; capillaries

Question 46

The routes of absorption of water and water-soluble food molecules: - water-soluble food molecules (e.g. monosaccharides, amino acids, minerals, water-soluble vitamins) → _________ and active transport → capillary - water → ________ → capillary

Answer 46

diffusion; osmosis

Question 47

The route of absorption of lipids and lipid-soluble food molecules: - fatty acids and glycerol → diffusion and ____________ → fine lipid droplets → lacteal - lipid-soluble vitamins → _________ → lacteal

Answer 47

recombining; diffusion

Question 48

The small intestine is very long. This allows sufficient ______ for absorption.

Answer 48

time

Question 49

The __________ of the small intestine brings digested food molecules into close contact with the villi and keeps a ______ concentration gradient for diffusion.

Answer 49

peristalsis; steep

Question 50

The highly-_______ inner wall of small intestine increases the surface area for absorption.

Answer 50

folded

Question 51

The _____ in the small intestine are finger-like and large in number. This increases the surface area for absorption.

Answer 51

villi

Question 52

The _______s and network of ________ies in villi transport absorbed food molecules away from villi rapidly. This keeps a steep concentration _________ of food molecules across the wall of the small intestine for rapid diffusion.

Answer 52

lacteals; capillaries; gradient

Question 53

The numerous _________ on the epithelial cells of villi further increase the surface area for absorption.

Answer 53

microvilli

Question 54

The __________ of the villus in small intestine is one-cell-thick. This reduces the diffusion distance for absorption.

Answer 54

epithelium

Question 55

In the large intestine, some of the remaining ______, minerals and vitamins inside are absorbed into the blood in the colon. The semi-solid material left inside is called _______.

Answer 55

water; faeces

Question 56

``` The transport of absorbed water-soluble food molecules in assimilation: capillaries in villi of small intestine ↓ hepatic portal vein _____ ↓ hepatic vein & vena cava ______ ↓ aorta other parts of the body ```

Answer 56

liver; heart

Question 57

The transport of absorbed lipid and lipid-soluble food molecules: _______s in villi of small intestine ↓ main _______ vessel, blood vessel near the ______ region and vena cava heart ↓ aorta other parts of the body

Answer 57

lacteals; lymph; neck

Question 58

Absorbed glucose is broken down by __________ in cells for releasing energy.

Answer 58

respiration

Question 59

Excess glucose is converted to _________ or lipids for storage.

Answer 59

glycogen

Question 60

Absorbed lipids are used by cells to make cell __________s and some hormones. It also acts as an energy reserve which is broken down to release energy when the body is short of _________.

Answer 60

membranes; glycogen

Question 61

Excess lipids are stored in the ________ tissues around the internal organs and under the _____.

Answer 61

adipose; skin

Question 62

Absorbed amino acids are used by cells to make ________s for growth and repair. They are also used to make ________s, antibodies and some hormones.

Answer 62

proteins; enzymes

Question 63

Amino acids are broken down when the stored ____________s and _____s are used up. Excess amino acids are broken down through ____________.

Answer 63

carbohydrates; lipids; deamination(脫氨作用)

Question 64

The role of the liver in carbohydrate metabolism: - regulates the blood g_______ level - stores g________

Answer 64

glucose; glucogen

Question 65

The role of the live in lipid metabolism: | - converts excess ____________s (e.g. glucose) and amino acids into lipids

Answer 65

carbohydrates

Question 66

The role of the liver in amino acid metabolism: - breaks down excess amino acids by ____________ - synthesizes non-essential amino acids

Answer 66

deamination

Question 67

The liver breaks down old _____ blood cells and stores the _____ released in the process.

Answer 67

red; iron

Question 68

The liver stores _____-soluble vitamins. It also converts _________ to vitamin A.

Answer 68

lipid; carotene(胡蘿蔔素)

Question 69

The liver produces _____ for the emulsification of lipids in the duodenum.

Answer 69

bile

Question 70

The liver breaks down certain mild toxic substances in the blood through ____________.

Answer 70

detoxification (解毒)