Human Digestion Flashcards

1
Q

Where does protein digestion begin?

A

Protein digestion begins in the stomach ( pepsinogen/pepsin )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the steps of digestion?

A

Ingestion, digestion, absorption, transport, assimilation, egestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why do human’s need to digest food?

A

Food molecules ingested are typically large insoluble macromolecules that must be hydrolyzed to be absorbed, to pass through cell membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the macromolecule of a protein?

A

Protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the form of a protein after digestion?

A

Amino Acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the macromolecule of a lipid?

A

Triglyceride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the form of a lipid after digestion?

A

Glycerol and fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the macromolecule of a carbohydrate?

A

monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the form of a carbohydrate after digestion?

A

Monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the macromolecule of nucleic acids?

A

DNA and RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the form of nucleic acid after digestion?

A

Nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the alimentary canal

A

long, muscular, digestive tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What composes accessory digestive organs?

A

liver, pancreas, and gall bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What composes the alimentary canal?

A

esophagus, stomach, small and large

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which canal does food pass through?

A

Alimentary canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where does food not pass through

A

liver, pancreas, gall bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do accessory digestive organs do?

A

Aid in digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where does chemical digestion occur?

A

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Mechanical digestion

A

physically breaking large molecules into smaller “chunks” ( chewing, mixing, churning of food )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the inner portion of the esophagus called?

A

The hollow inner portion of the esophagus is called the lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Chemical digestion

A

Hydrolysis ( enzymes ), macromolecules hydrolyzed into smaller and smaller molecules through enzyme-catalyzed reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Hydrolysis

A

catabolic reactions that dominate the digestive process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Enzymes

A

enzymes are globular proteins that lower the activation energy needed to start a chemical reaction and speed up the rate of chemical reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where are digestive enzymes released into?

A

The gut from the exocrine glands and pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What do exocrine glands have?
ducts and secrete substances to an epithelial surface
26
Where is salivary amylase produced?
Salivary glands
27
Where is the site of action for salivary amylase?
Mouth/ esophagus
28
Where is pepsin/protease produced?
Gastric glands and stomach cells
29
Where is the site of action for pepsin/protease?
Stomach
30
Where is amylase produced?
Pancreas and salivary glands
31
Where is the site of action for amylase?
Lumen of the small intestine
32
Where is endopeptidase/protease produced?
Pancreas
33
Where is the site of action for protease/ endopeptidase?
Lumen of the small intestine
34
Where is lipase produced?
Pancrease
35
Where is the site of action for lipase?
Lumen of the small intestine
36
Where is nuclease produced?
Pancreas
37
Where is the site of action for nuclease?
Lumen of the small intestine
38
What are the three main parts of the alimentary canal?
Stomach, Small Intestine, Large Intestine
39
What do nervous and hormonal mechanisms control?
the section of digestive juices and control the volume of content of the gastric secretions
40
What do HCl conditions in the stomach do?
HCL conditions in the stomach favor some hydrolysis reactions and help to control pathogens in ingested good
41
Pepsinogen
a protease that hydrolyzes peptide bonds in proteins
42
How is pepsinogen activated?
Pepsinogen is activated into pepsin in the stomach by HCl
43
What does HCl in the stomach help?
HCl in the stomach helps to initially denature proteins and kill pathogenic bacteria and fungi in ingested foods
44
How are acidic conditions in the stomach maintained?
Acidic conditions of the stomach are tainted by proton pumps in parietal cells in the gastric pits
45
How are acidic conditions in the stomach maintained?
Acidic conditions of the stomach are tainted by proton pumps in parietal cells in the gastric pits
46
Stomach uvlers
inflamed/ damaged areas of open sores in the stomach wall
47
What causes stomach ulcers?
caused by exposure of stomach cells to stomach acid
48
How does helicobacter pylori survive acidic conditions in the stomach?
Penetrates mucus lining ( mucosa )
49
What additional factors can cause ulcers?
Stress/diet/ overuse of aspirin, ibuprofen, NSAIDS
50
Where do exocrine glands do?
Exocrine glands secrete to the surface of the body or lumen of the gut
51
Exocrine glands in the digestive system
liver, gall bladder, pancreas, salivary glands, intestinal lands, gastric glands
52
Describe exocrine glands
Exocrine glands have ducts ( tube-like structures ) through which their products are secreted
53
Which ducts secrete digestive juices?
Salivary glands, gastric glands, pancreas, glands in the wall of the small intestine
54
What is similar to all digestive juices?
all contain water, mucous, and salts
55
What are the digestive juices?
saliva, gastric juice, and pancreatic juice
56
Where is saliva found?
mouth/throat
57
What is the function of saliva
convert starch into maltose
58
Where is gastric juice found?
stomach
59
What is the function of gastric juice?
Convert proteins into polypeptides
60
Where is pancreatic juice found?
Small intestine/ duodenum
61
What is the function of pancreatic juice?
Convert proteins into polypeptides, convert triglycerides into glycerol + fatty acids, and convert starch into maltose
62
What do most enzymes digest?
Enzymes digest most macromolecules in food into monomers in the small intestine
63
What does the pancreas secrete?
The pancreas secretes enzymes into the lumen of the small intestine
64
Where are enzymes secreted>
Enzymes are secreted by the pancreas through a duct into the lumen of the small intestine
65
Serosa
Protective outer covering
66
Longitudinal muscles
Peristalsis (move food along gut/ mix with enzymes)
67
Circular muscles
Segmentation (prevent backward movement of food/ mix with enzymes)
68
Submucosa
Separates innermost mucosa from muscles
69
Mucosa
Highly folded inner epithelial layer (villi and microvilli) to increase the surface area for absorption of monomers from the intestinal lumen
70
Mucosa
Highly folded inner epithelial layer (villi and microvilli) to increase the surface area for absorption of monomers from the intestinal lumen
71
Lumen
The lumen (inner-most, hollow tube) of the small intestine is lined with folded/ finger-like (increased surface area) projections of the mucosa called villi
72
What do microvilli increase?
Microvilli increase the surface area for absorption
72
What do microvilli increase?
Microvilli increase the surface area for absorption
72
What do microvilli increase?
Microvilli increase the surface area for absorption
73
What are the different methods of membrane transport?
Diffusion, osmosis, facilitated diffusion, active transport, exocytosis
74
Diffusion
Fatty acids and other small, non-polar substances easily pass through the hydrophobic cell membranes of epithelial cells through simple diffusion
75
Osmosis
Water diffuses across epithelial cell membranes in response to movement of ions and other hydrophilic monomers (occurs in small intestine and large intestine)
76
Facilitated Diffusion
Protein channels within epithelial cell membranes (of villi and microvilli) allow passage of hydrophilic food molecules (water-soluble/ polar molecules like fructose, vitamins, glucose, amino acids, and minerals)
77
Active transport
Glucose and amino acids are pumped (membrane proteins) against their concentration gradients, or they are transported with Na+ ions (co-transport) as Na+ ions are actively pumped across the membrane (secondary active transport)
78
Endocytosis
Invagination of the cell membrane to form a vesicle around bulk fluids/ large molecules that must remain intact in the intestinal lumen and bring them into the cell (pinocytosis: “cell drinking”)
78
Endocytosis
Invagination of the cell membrane to form a vesicle around bulk fluids/ large molecules that must remain intact in the intestinal lumen and bring them into the cell (pinocytosis: “cell drinking”)
79
What is the main function of the large intestine?
Absorbs water/minerals/vitamins/ions
80
Egestion
Materials not absorbed are egested= BELCH
81
Rate of transit is correlated with what...
he RATE of transit of materials through the large intestine is positively correlated with their fiber content (More fiber = faster rate of transit = less exposure to undesirable food chemicals etc./ decreases contact time between intestinal wall and food)
82
Why is fiber in the diet important?
helps “clean out” old/ damaged intestinal cells and unabsorbed materials, it provides bulk to keep materials moving, it absorbs water to keep faeces soft and easy to pass, “works out” the body’s normal microflora, reduces frequency of constipation, lowers risk of colon and rectal cancers, lowers blood cholesterol, regulates blood sugar levels (slows absorption rate of glucose), and decreases hunger (aids in weight management/ prevention of obesity)
83
Chlorea toxin causes
Dehydration
84
Vibrio cholerae
bacterial pathogen that infects intestines
85
Why does cholera toxin cause dehydration?
V. cholerae releases a toxin that binds to a receptor on the epithelial cells in the intestine.