Nutrition, Digestion, Absorption Flashcards Preview

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Flashcards in Nutrition, Digestion, Absorption Deck (140):
2

Heterotrophs

Gain nutrients by eating other organisms

3

Autotrophs

Solar energy => photosynthesis

4

T/F: heterotrophs depend on organic synthesis of autotrophs

True

5

A calorie

Heat needed to raise the temp of 1 gram of water by 1 degree Celsius

6

1 Cal =

1000 calories , 1kcal

7

1 joule =

0.239 cal

8

Metabolic rate

Measure of overall energy that needs to be met by food

9

Three sources of energy for the body

Fats, carbs, proteins

10

Basal metabolic rate

Metabolic rate at rest / rate to perform body functions at rest

11

T/F: Physical activity does not increase basal metabolic rate

False

12

Describe the order of substance the body uses as an energy source.

1. Fats - more energy/gram and compact for storage b/c little H2O2. Carbs- stored in liver and muscle as glycogen3. Protein- metabolized as a last resort

13

Undernourishment

Too little food intake- own cells are metabolized. Body functions impairedCarbs to fat to proteins

14

Overnourishment

Too much intake- increased body massCarbs to fat to protein reserves filled and fat turns into body fat

15

T/F: humans digest outside the body

True

16

The body cavity where food is processed

The gut

17

T/F: The digestive system is continuous with the outside world

True

18

Enzymes secreted that break down food are from (general)

Exocrine glands

19

Describe general process of protein digestion

Broken down into amino acids, function differently in different species. If it entered the gut directly the immune system would pwn it

20

8 essential amino acids for humans

TTMV PILLTryptophanThreonineValinePhenylalanineIsoleucineLeucineLysine

21

You are outside the body as long as you don't cross the plasma membrane

True

22

Three main parts of digestive tract (general)

Mouth, gut (tubular), anus

23

Villi and microvilli increase what in the intestine? What happens As a result?

Increases surface area.Absorption is maximized

24

Layers of the gut, inside to out

LumenMucosaSubmucosaCirculatory layerLongitudinal layerEnteric nervous systemPeritonium

25

The lumen

Center/ cavity of the gut

26

Mucosa

Epithelium lining + connective tissue (blood vessels and glands)

27

Submucosa

Neural networkIncludes two muscle layers: Circular layer and longitudinal(takes part in stomach aches)

28

Enteric nerve system

Nerve nets of neurons of the gut

29

Petronium

Slimey layer that prevents organs from chafing

30

Hydrolytic enzymes are

Digestive enzymes

31

Paritoid gland is

The top salivary gland

32

Sublingual / submandibular gland

Bottom salivary gland

33

Salivary glands secrete

Mucus an amylase

34

Mucus is

Mucin (glycosylated proteins) and inorganic salts in H2O

35

Amylase is

Carbohydrase that turns starch into maltose

36

Bolus is

Ball of food that is covered in mucus/saliva that slides down the esophagus

37

How do salivary glands help swallow food

It covers the oral cavity and esophagus in mucus

38

Food touches epithelial cells as it gets processed through the body

False

39

Saliva solubizes dry food so it can go down without scratching the throat

True

40

Describe how saliva takes care of oral hygiene

Constantly flushes mouthContains lysozyme that lyses bacteria

41

What enzyme breaks down starch and what does it turn it in to?

Amylase and turns it into maltose

42

Is amylase present in large quantities in carnivores?

No

43

Stomach fluid is made of what

HCl

44

What is a zymogen

Inactive enzyme precursor

45

The exocrine part of the pancreas secretes

Bicarbonate into the small intestine to neutralize HCl

46

Protein is stored for energy

FLASE

47

Describe the make-up and properties of fat

Anhydrous - hydrophobic tail/hydrophilic headSaturated with C-H bonds (triglycerides; hydrocarbons)Reside in adipose tissue

48

Circular layer

In SubmucosaConstricts gut

49

Longitudinal muscle

In Submucosa Lengthens gut

50

Circular and longitudinal muscle layers take part in

Peristalsis

51

Two substances that activate pepsinogen

HClPepsin

52

Autocatalysis and what type of feedback? Give an example

A substance can cleave its own inactive state to produce more active enzymeEx: pepsinogen and pepsin

53

An Enteric nervous system

One that can act on its own (ex: digestion in a coma)

54

When looking at digestion you are looking at the _____

Peritonium

55

Mucous = Mucus =

cellsLiquid in salivary glands

56

Lysozyme and potency

Agent in saliva that kills bacteria, but only bacteria not strong enough to escape it

57

Stomachs main function

To STORE food

58

Which is faster in the stomach: ingestion or digestion?

Ingestion

59

Digestion mainly happens in the

Small intestine

60

The Jejunum is part of what organ and what does it do?

Small intestine and absorption

61

Ileum is part of of what organ and function?

Small intestine and absorption

62

The duodenum is part of what organ and what's its function

Small intestine and digestion

63

The duodenum requires help from _____ organs. They are the ____ and _____

Accessory organs and pancreas and liver

64

What are the accessory organs and are they a part of the digestive system?

Pancreas and liver. No they are not

65

What does the liver do for the digestive system

Secretes bile to break down fats

66

A zymogenic cell contains lots of

Rough ERs

67

Where is the pepsinogen protein modified?

Zymogenic cell

68

The parietal cell has lots of

Mitochondria to create energy for anti-porters using ATP

69

Partially digested food

Chyme

70

Major enzyme produced by the stomach?

Pepsin

71

Describe the act of HCl activating pepsin from pepsinogen

The inactive pepsinogen has a masking sequence that falls off in low pH conditions (HCl) and reveals the active site

72

True/False: pepsin is a protease

True

73

What is secreted by stomach cells to prevent what from digesting the stomach?

Mucus prevents proteases and HCl from digesting the stomach

74

What develops when the stomach is directly exposed to HCl/pepsin

Stomach ulcers

75

Stomach ulcer is cause by what specific bacterium

Helicobacter pylori

76

What causes urease to convert urea to bicarbonate and ammonium?

Bacteria

77

Muscles of the stomach walls ____ and ____ to mix contents with stomach secretions

Contract and expand

78

What type of contractions push the chyme into the digestive organs?

Peristaltic conteactions

79

What is the opening to the small intestine called?

Pyloric sphincter

80

Properties of the small intestine

Long but small in diameterSurface area the size of a tennis court3 structural parts

81

What are the 3 parts of the small intestine

DuodenumJejunumIleum

82

Through what does the liver secrete bile?

Common bile duct into the duodenum

83

What organ stores bile until needed?

Gallbladder

84

What does the pancreas do for digestion?

Secretes digestive enzymes and bicarbonate

85

Bile is mainly made of what and acts as

Salts - emulsifiers

86

Another name for emulsifiers and what does it do?

Surfactants- cuts up fat into smaller chunks to increase surface area

87

What are the small chunks of fat called?

Micelles

88

T/F:Emulsifiers have a lipophilic and lipophobic end

True

89

Lipases break down fats into ______ and ____ so they are able to pass through the microvilli

Di/monoglycerides and fatty acids

90

Once inside the cell glycerides and fatty acids are re-synthesized into ______

Chylomicrons

91

Chylomicrons are

Water soluble "lipoprotiens"

92

What do chylomicrons enter the blood through?

Thoracic ducts

93

Chylomicrons also pass into which two tissues?

Lymph vessels and Submucosa

94

Bile acids are synthesized from what

Cholesterol

95

What percent of bile is recycled and where

90% in the liver

96

Process of recycling bile is called

Enterohepatic circulation

97

What percent of bile is lost and where?

10% in poop, the major elimination method of cholesterol

98

Bolus enters the stomach through the

The lower esophageal sphincter

99

Lipoproteins consist of

A core of fat and cholesterol covered in apoliproteins

100

What allows lipoproteins to be water soluble?

Apoliproteins

101

Lipoproteins are _____ in the circulatory system

0

102

Lipoproteins are classified according to ______ . The more fat the ______ they are.

Density, the more fat the less dense

103

Chylomicrons are the _____ form of lipoproteins

Largest

104

What carries fat from intestines to liver and adipose tissue?

Chylomicrons

105

Which lipoproteins carry new triglycerides from the liver to adipose tissue?

Very low density lipoproteins (VLDL)

106

What lipoproteins carry cholesterol from the liver to the cells of the body? Good or bad cholesterol?

Low density (LDL)

107

What lipoproteins collect cholesterol from cells and bring it to the liver? Good or bad?

High density (HDL)Good

108

High LDL to HDL ratio is a risk for what?

Atherosclerotic heart disease

109

Which part of the pancreas plays a part in digestion?

The exocrine portion

110

The exocrine part of the pancreas releases digestive enzymes as

Zymogen

111

What zymogen enzyme does the pancreas secrete

Trypsinogen

112

What activates trypsinogen and where?

Activated by enterokinase in the duodenum

113

What produces the enterokinase for enzyme activation?

The cell lining of the duodenum

114

Through what process can active trypsin perform to activate trypsinogen

Autocatalysis

115

The exocrine part of the pang read secretes what to neutralize stomach HCl?

Bicarbonate

116

T/F:!Only the smallest products of digestion can pass through the mucosa

True

117

Final digestion takes place where?

At the microvilli

118

Another name for where final digestion takes place?

Apical plasma membrane

119

What resides on microvilli membranes that cleave proteins?

Peptidases

120

What other "-ases" do the epithelial walls of the intestine produce? (to break down polysaccharides)

Maltase, lactase, and sucrase

121

What action pushes contents into the large intestine?

Peristalsis

122

What is another name of the large intestine

The colon

123

What does the colon absorb ad what is the product of that

Absorbs water and ions, makes feces out of indigestibles

124

Too much water absorption =Too little =

ConstipationDiarrhea

125

What bacteria lives in the colon and what does it do?

Escherichia coli- makes vitamin k and biotin

126

Why is it bad to take antibiotics

0

127

The logic in producing an inactive enzyme first is that

There is no damage to the tissue of the cell producing it

128

Blood vessels are connected to the _____ and ____ via _____

Parietal cell and lumen of the gastric pit via anti-porters

129

The parietal cell is connected to the lumen of the gastric pit via

Anti-porters and ion channels

130

What is the product of metabolism

CO2

131

In the parietal cell, CO2 reacts with what to make what and forms what as a by-product?

Water to make H2CO3 and forms bicarbonate as a by-product

132

The catalyst for the reaction between water and CO2 is

Carbonic anhydrase

133

Synthesized bicarbonate diffuses into the _____ while what ion comes in at the same time?

Bicarbonate diffuses into the blood stream while Cl- ions flow in

134

What ion constantly enters the parietal cell from the lumen of the gastric pit while which ion from the CO2 and water reaction goes in the opposite direction to the lumen?

K+ enters parietal from the lumen and H+ enters lumen from parietal

135

Once the H+ ion enters the lumen

It reacts with the Cl- ions to makeHCl the stomach acid

136

In the stomach, HCl is _____ and acts as a _____ to any bad substances

Acid-label and acts a defense

137

What does acid-label mean

Anything that can be acted on by acid (HCl)

138

What is the function of pepsin in the stomach?

To break down proteins at the tertiary structure

139

What type of cell secrets pepsinogen

Chief/zymogenic cell

140

Which cell secretes HCl?

The parietal cell

141

Where do gastric glands reside?

In the lining of the stomach