Unit D: The Digestive System Flashcards
(119 cards)
1
Q
What are carbohydrates?
A
main source of energy for the body
molecules → contain at least 1 carbon, 2 hydrogen and 1 oxygen atom.
2
Q
What are the 3 types of carbohydrates?
A
- Monosaccharides:
- Disaccharides:
- Polysaccharides:
3
Q
What are monosaccharides?
A
- Monosaccharides: single sugar unit → “reducing” sugars (3-8 carbons)
4
Q
What are disaccharides?
A
Disaccharides: 2 sugar units → type of reducing sugar formed by “linking together” (of monosaccharides) (7+ carbon atoms)
5
Q
What are the 3 types of disaccharides?
A
- Sucrose: formed by Rx b/w glucose and fructose
- Maltose: formed by Rx b/w 2 glucose molecules
- Lactose: formed by the reaction b/w glucose and galactose
Ex. Sucrose, maltose, lactose
6
Q
What are polysaccharides?
A
Polysaccharides: 2+ sugar units → “complex carbohydrates” (many simple sugars linked)
Ex. starch, cellulose (hard to eat/break down = complex)
7
Q
What are isomers?
A
carbohydrates with the same chemical formula but arranged differently
Ex. 3 monosaccharides - all contain 6C, 12H, 6O but have different configuration
8
Q
What is dehydration synthesis?
A
involves the combining of reacting molecules to make a large molecule, following the loss of water. This type of reaction is also classified as a condensation reaction.
- aka condensation = involves the loss of a hydroxide (OH-) ion from one monomer → bond w/ single sugar units
Result: release of water (byproduct)
9
Q
What are lipids
A
main component of cellular membranes, act as carriers for vitamins, synthesis for hormones. = essential for cellular functioning (used to stored produced energy)
carbon-based, non-polar, repel water, waxy/oily consistency
10
Q
what are fatty acid chains?
A
Fatty acid chains: (hydrocarbon chain + csrboxyl group) = lipid building blocks
11
Q
What are saturated fatty acids?
A
Saturated (‘bad’ fats): single-bonded carbon chain, rectangular shape → chains are packed together → difficult to break down (solid at room temp)
12
Q
What are unsaturated fatty acids?
A
Unsaturated ‘good fats’): one or more double bonds in the carbon chain = kinked shape → cannot easily be packed together → easy to break down (liquid at room temp)
13
Q
Which fatty acid is a single bond?
A
Saturated
14
Q
What shape is a saturated fat
A
rectangular
15
Q
What shape are unsaturated fats?
A
Kinked shape
16
Q
What is the state of saturates vs unsaturated fats at room temp
A
Saturated: solid
Unsaturated: liquids
17
Q
Which fatty acid is easier to break down?
A
unsaturated
18
Q
What are the 4 examples of lipids?
A
- Triglycerides
- Phospholipids
- Cholesterol
- Trans Fat
19
Q
What are triglycerides?
A
union of glycerol (3-carbon lipid) + 3 fatty acids
20
Q
What state are triglycerides at room temp?
A
- Solid at room temp = fats (saturated) (from animals)
- Liquid at room temp = oils (unsaturated) (from plants)
STORED ENERGY for cells (in fat cells released into bloodstream)
21
Q
What are phospholipids?
A
similar to triglycerides structurally
Difference = 1 fatty acid tail replaced by a phosphate group
Cell membranes
AMPHIPATHIC
22
Q
What are amphipathic?
A
(both hydrophobic and hydrophilic ends) → POLAR molecules (lipids)
23
Q
What is cholesterol and its purpose?
A
help maintain cell membrane fluidity → produces hormones
based on a carbon ring structure (NOT fatty acid chain) → produced in LIVER
AMPHIPATHIC
24
Q
What is considered BAD cholesterol?
A
BAD cholesterol = low-density lipoprotein
25
What is considered GOOD cholesterol?
GOOD cholesterol = high-density lipoprotein HDL
Carries low-density cholesterol → liver → breaks down (cops and robber analogy)
26
What are trans fats and how are they formed?
chemically altered unsaturated fatty acid
High in LDL(bad)
Formed through hydrogenation (unsaturated → saturated by breaking double bonds)
27
What are proteins?
form structural components of the cell (NOT primary source of energy)
28
What are the 3 purposes of proteins?
Repair damaged cells
Speed up chemical reactions (ENZYMES)
Help defend against disease (ANTIBODIES)
29
What are polypeptides?
protein building blocks --> chains of amino acids
30
How many polypeptides does a lysosome have?
1 polypeptide
31
where are lysozymes found in the body? (protiens)
found in nasal fluid, tears
32
What do lysozymes do?
Kills bacteria by breaking down their cell walls
33
How many polypeptides does integrin have?
2 polypeptides
34
What is integrin? (protein)
Membrane protein, makes connections b/w structures in and out of cell
35
How many polypeptides does collagen have?
3 polypeptides
36
What is collagen? (protein)
Structural protein → tendons, ligaments, skin + blood vessel walls
high tensile strength
37
How many polypeptides does hemoglobin have?
4 polypeptides
38
What is hemoglobin? (protein)
Transport protein, allows red blood cells to carry O2 through body
39
What do enzymes do to activate the energy of reactions
It decreases the activation of energy of reactions
40
What is the Lock and key method?
ALLOWS substrates (specific molecule) to fit into active site = enzyme-substrate complex
41
What are 3 factors that influence chemical reactions of enzymes?
1. Temperature
2. pH
3. Substrate concentration
42
How does temperature influence the reaction of enzymes
Increases the temperature = increase in the amount of energy in a chemical system/activity
43
What is denaturing? How does it happen
(beyond 37*C) when proteins break apart = decreased enzyme activity = precipitate (skin that forms on milk when heated)
44
How is pH and influencer for chemical reactions of enzymes?
Enzymes function best at a specific pH
Deviation of levels = possible denaturing
45
How is substrate concentration a factor influencing enzyme reactions?
enzymes can only catalyze a reaction if substrate (substance where an enzyme acts) binds → active site (receptor)
Substrate site increases = enzyme activity increases (limited by amount of enzymes)
46
What is hydrogenation?
The breaking of double bonds and addition of hydrogen used to convert unsaturated fats (oils) → saturated (butter)
47
-ase
enzyme
48
-ose
sugars
49
what does lipase do?
breaks down lipids
50
What does amylase do?
breaks down starch
51
what does protease do?
Breaks down proteins
52
What are accessory enzymes? (examples)
secrete enzymes DON’T handle food
Ex. salivary glands, liver, gallbladder, pancreas
53
3 types of enzymes in the pancreas
1. Trypsin and Chymotrypsin: digest proteins → amino acids
2. Pancreatic amylase: digests starch → disaccharides
3. Lipase: digests lipids → fatty acids
54
What does the pancreas do?
delivers fluid containing many enzymes → small intestine
55
What is the role of the liver?
secrete bile salts
56
What is the liver?
The largest gland in the body
- Directly under the diaphragm
57
Which accessory organ plays a key role in the digestion of fats?
Liver
58
What enzymes are secreted by the liver?
*Bile salts:
Emulsifying lipids:
59
How are bile salts helpful?
help lipases secreted(by pancreas) break down fats (w/ emulsifying lipids)
- Bile salts: doesn’t digest fat but keeps it in smaller clumps (helps maintain greater SA) → easier for enzymes to break down
60
What do emulsifying lipids do/help with?
make fats more accessible by lipase
61
what is the gallbladder?
Stores bile
Hormones tell bile to squirt and contract bile through bile ducts into duodenum
62
What does the digestive tract/alimentary canal do? (+ examples)
moves food through the body
Ex. mouth, esophagus, stomach, small/large intestine, rectum, anus
63
What is the first step to the movement of food ?
the mouth (where food enters)
64
What kinds of breakdown does the mouth do?
Mouth and teeth: mechanical breakdown (chew into smaller pieces)
Chemical breakdown: Salivary glands: enzymes secreted
65
What enzyme is secreted in the mouth?
salivary amylase
66
What is the enzyme, salivary amylase
enzyme → breaks down starch → disaccharides (chemical digestion)
67
What do the salivary glands do in the mouth?
*salivary glands: secrete saliva → contains salivary amylase
(support chemical digestion)
68
What does the tongue do for the digestive tract?
Tongue: pushes bolus to back of mouth for swallowing
69
What is bolus?
balls of food
70
What does the esophagus do?
moves partially digested food = pushed down → stomach
- bolus enters the esophagus --> stomach
71
Peristalsis
Wave-like contractions of the esophageal tissue
72
esophageal sphincter:
rings of muscle → remains tightly shut (prevents stomach acid splashing = heartburn)
73
What kind of breakdown does the esophagus do?
Physical(churning process by muscular layers) and chemical(stomach acid) digestion
74
What kind of digestion does the stomach do?
muscle contractions = physical digestion
Chemical digestion: Enzymes and stomach acids
75
What is dissolved from the stomach into the bloodstream?
Water + salts absorbed → bloodstream
76
What is pepsin?
*pepsin: protein-digesting enzyme → breaks down protein present in food
77
What does mucus for the stomach?
Mucus: stomach lining → prevents acid from digesting the stomach lining
78
What is chyme?
Nutrient absorption: chyme → forms when gastric juices mix with bolus.
79
what is the function of the small intestine?
to complete the digestion of MACROMOLEUCLES
80
What is secreted in the small intestines?
enzymes
81
What do enzymes do in the small intestine?
Enzymes from the pancreas and liver = secreted into → small intestine to finish chemically digesting food. (digests lipids, proteins, starches)
82
What do additional enzymes in the small intestine help to do?
completes digestion of nutrients
83
What are the 3 parts of the small intestine?
1. Duodenum
2. Jejunum
3. Ileum
84
What is the duodenum?
The first part of the small intestine connects to the stomach
85
What happens in the duodenum?
helps to further digest food coming from the stomach
- absorbs nutrients + water from food to be used
- receives partially digested food from the stomach, mixes with digestive --> breaks down
86
Which process happens in the duodenum?
The absorption of vitamins, minerals and other nutrients
87
What is absorbed in the duodenum
vitamins, minerals, carbohydrates, fats, proteins and water from food (can be used by the body when processed)
88
What is the jejunum?
The middle part of the small intestine
89
What happens in the jejunum?
helps to further digest food coming from the stomach
- Most nutrient absorption takes place
- also helps to further digest food by mixing it with digestive juices, moving it along the digestive tract
90
What is primarily absorbed by the jejunum
- important nutrients =
primarily carbohydrates, sugars, amino acids and fatty acids
91
What is the ileum, and what does it do?
The final, longest segment of the small intestine is responsible for the reabsorption of conjugated bile salts and absorption of vitamin B12
92
What is absorbed by the ileum?
bile acids, fluid, vitamin B-12
93
what are segmentations?
(small folds in small intestine) used to increase SA
- type of intestinal motility that involves the circular muscles contracting and relaxing to move food back and forth in the intestine.
94
What do segmentations contain to increase SA
Specialized structures (villi/microvilli) Absorb digested nutrients → bloodstream
95
what is the function of the large intestine?
concentrate/eliminate waste materials (rectum + anus)
- absorb water and electrolytes from undigested food matter, converting it into soild waste (feces)
96
What is primarily absorbed in the large intestine?
water and electrolytes from undigested material left over from the digestive process
97
What does the bacteria in the large intestine do?
Bacteria: release vitamins from food/breaking down undigested ( produces B-12 and K)
98
Does digestion occur in the large intestine?
NO
99
What are the 4 parts of the large intestine?
1. Cecum
2. Colon
3. Rectum
4. Anal canal
100
3 main functions of the large intestine
1. Absorb water and electrolytes
2. producing and absorbing vitamins
3. Forming and propelling feces toward the rectum for elimination
101
what is the rectum?
where waste enters and is held until secreted
102
What is the anus?
where the remaining food exists
103
What is the appendix? (vestigial and possible purpose)
Previously vestigial (no purpose) → now: serves as storage site for ‘good’ bacteria → aiding digestion
Food passes (si and li) → uses good bacteria from appendix to digest
104
What is cirrhosis?
formation of scar tissue on the liver
105
What is the possible result of cirrhosis?
result from expressing alcohol intake
106
What are the symptoms of cirrhosis:
weakness, exhaustion, nausea
107
What are gallstones?
hardened deposits that form in the gallbladder, a small organ that stores bile, a digestive fluid from the liver.
108
What is the cause of gall stones?
high cholesterol from fatty foods (causes gallstones to form)
109
What is the treatment for gall stones?
surgical removal (they are very painful)
110
What is appendicitis:
Absorption of bad bacteria = inflamed/infected
111
What are the symptoms of appendicitis?
pain/ tenderness un lower right abdomen/nausea/vomiting
112
What is the treatment for appendicitis?
= surgical removal (fail could = death)
113
What is Irritable Bowel Syndrome (IBS)
Inconsistent bowl movements in large intestine
114
Is IBS an acute or chronic condition?
chronic
115
What are the symptoms of IBS
Bloating, changing bowel movements, and abdominal pain
116
what is constipation
Difficulty passing stools (rectum and large intestine issues)
117
What is the treatment for constipation
- increase fibre intake
- more fluids
- regular exercise
118
What are peptic ulcers?
Sores in the lining of the stomach or duodenum
119
What is obesity
Increase in body mass or a person due to nutrition, genetics, athleticism etc.
