Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

biology 153 > digestive system (physiology) > Flashcards

digestive system (physiology) Flashcards

(59 cards)

Start Studying
1
Q

two forms of digestion

A

mechanical and chemical digestion

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

what is mechanical digestion

A

breakdown of large food particles into smaller food particles
-involves, teeth, stomach, small intestine
stomach is churning
small intestine is segmentation

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

what is chemical digestion

A

enzymatic breakdown of organic macromolecules into smaller molecules (monomers); chemical bonds broken

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

what are enzymes

A

proteins that catalyze biological reaction

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

how do enzymes facilitate chemical reactions in the body?

A

lower activation energy of biological reactions (allow them to take pace quickly at body temp)

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

can enzymes catalyze any reaction?

A

no they are very specific and bind to specific substrates

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

what are the reactants in an enzyme catalyzed reaction called

A

substrate

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

what are some factors that affect the rate of enzyme catalyzed reactions?

A

pH, enzyme concentration, temperature

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

enzyme has an active site for the substrate, and then..

A

enzyme-substrate complex forms, products are made.
products release energy when bonds are broken
energy is used to make ATP

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

enzyme is changed or unchanged

A

unchanged, can catalyze other reactions

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

chemical digestion involves _______ reactions

A

catabolic

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

catabolic reactions are ..?

A

exergonic/exothermic. energy is released when chemical bonds are broken, energy is used to make high energy phosphate bonds in ATP

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

what are the 3 main macromolecules in the diet that are digested chemically

A

protein, carbohydrate, fat (lipids)

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

chemical digestion of protein

A

very long polymer of amino acids- peptide with peptide bonds- amino acid

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

chemical digestion of carbohydrate

A

complex carb (starch, glycoge)- disaccharides (sucrose, maltose, lactose)- monosaccharides (glucose, fructose, galactose)

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

chemical digestion of fats (lipids)

A

triglyceride- glycerol and fatty acids

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

where does absorption of nutrients occur

A

mainly in small intestine (especially ileum and jejunum) across brush border membrane

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

the small nutrient molecules move into epithelial cells, then..

A

into blood or lymph capillaries (lacteals)

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

how are sugars and amino acids transported

A

by cotransport or facilitated diffusion

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

products of protein and carbohydrate digestion enter?

A

capillaries in the lamina propria- hepatic portal vein- liver

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

monoglycerides and fatty acids..

A

lipid soluble diffuse across brush border membrane, no transporters
-not water solube, must be coacted in proteins and phospholipids to be transported in blood or lymph

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

what are the lipoproteins called

A

chylomicrons

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

what are micelles

A

bile coated fat droplets containing fatty acids and monoglycerides

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

what happens when fatty acids and monoglycerides diffuse across c.m?

Study These Flashcards
A

reassembled into triglycerides then combined with cholesterol, phospholipids, and proteins to form chylomicrons

25
how do the chylomicrons leave into blood?
chylomicrons leave by exocytosis | -chylomicrons are too large to move into capillaries, so they are picked up by lacteals
26
what do lacteals do
deliver fatty chyle to cisterna chyli- thoracic duct- veins
27
where do chylomicrons go once they are in the blood?
-enzyme lipoprotein lipase in endothelium of capilaries breaks down the triglycerides into monoglycerides and fatty acids
28
fatty acids are stored?
in adipose tissue (as triglycerides) muscle (for energy) liver (processing center)
29
where are lipoproteins synthesized?
the liver
30
lipoprotein function
deliver lipids (triglycerides, cholesterol) to and from liver and tissues
31
LDL ?
low density lipoprotein (lots of lipid, less protein) | transports lipids from liver to tissues
32
how does LDL transport lipids
receptor mediated endocytosis (pulls lipids into cells) | can be deposited in endothelium (becomes plaque under endothelium)
33
HDH ?
high density lipoprotein (less lipid, more protein) good cholesterol transports lipids from cells to liver, can be excreted in bile
34
how are water soluble vitamins absorbed
``` facilitated diffusion (C and B vitamins) except B12 which must be bound to intrinsic factor glycoprotein secreted by parietal cells of stomach) ```
35
how are fat soluble vitamins absorbed
A,D,E,K diffusion with lipids (incorporated into chylomicrons)
36
what is pernicious anemia caused by
genetic defect in the gene that codes for intrinsic factors; individuals cannot absorb B12 which is required for cell division
37
how are ions/ electrolytes absorbed
transporters are required, facilitated diffusion or active transport
38
how does water enter the GI tract
from food/beverages and GI secretions
39
how much water is ingested a day
2000 mL
40
digestive secretions include?
saliva, gastric secretions, intestinal secretions, pancreatic secretions, bile
41
water is reabsorbed by?
process of osmosis
42
where is water reabsorbed
small intestine 97% large intestine 6-7% only about 150ml a day is excreted in feces
43
what is digestion regulated by
- hormones | - ANS: enteric plexus (network of sensory and motor neurons in GI tract)
44
three phases of digestion
1. cephalic phase 2. gastric phase 3. intestinal phase
45
cephalic phase of digestion
before food enters stomach | -sight, smell, touch, taste, thought- hypothalamus- parasympathetic increases saliva and gastric juice secretion
46
gastric phase of digestion
activated by arrival of food in the stomach - stimulates chemoreceptors and stretch receptors that increase gastric juice and gastric motility - gastrin secretion (hormone by G cells) - parasympathetic (vagus nerve)
47
what is the intestinal phase
activated by arrival of acid chyme in duodenum -chemoreceptors and stretch receptors -duodena endocrine cells secrete hormones (secretin and CCK- cholecystokinin) -parasympathetic activation
48
secretin causes
pancreatic NaHCO3 to increase bile secretion by liver to increase gastric secretion and motility to decrease
49
CCK (cholecystokinin) causes
``` pancreatic enzyme secretion to increase gallbladder concentration to increase relaxes hepatopancreatic sphincter increase pancreatic NaHCO3 decrease gastric secretion and motility ```
50
parasympathetic activation causes
increased intestinal motility, vagus nerve and reflexes
51
GIP (glucose dependent insulinotropic peptide)
- secreted when sugars and fats enter duodenum - stimulates insulin secretion by pancreas - stimulates lipogenesis in adipocytes
52
VIP (vasoactive intestinal peptide)
- stimulates intestinal glands to increase NaHCO3 and water secretion - dilates intestinal blood vessels to increase blood flow
53
how is defecation controled
mass movements (peristalsis) cause the urge to defecate, initiated by arrival of food in stomach and intestine
54
arrival of food causes which reflexes
gastrocolic and duodenocolic reflexes
55
distension of rectum with feces causes
defecation reflex, relaxation of internal anal sphincter
56
the internal sphincter is under what control?
parasympathetic, conscious control of external (voluntary)
57
regulation of appetite?
satiety centers in hypothalamus regulate feeding behaviours
58
short term regulation of appetite
stretch receptors in stomach decrease appetite | -ghrelin (hormone secreted by cells lining stomach when empty) increase appetite
59
long term regulation of appetite
leptin (hormone secreted by adipose tissue) | increase adipose tissue, increases leptin, decreases appetite

biology 153 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions