I M: Metabolism, glycolysis, TCA cycle; Metabolism of CHO Flashcards

0
Q

food passes into stomach via the? passes through the?

A

via the esophagus, through the fundus

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1
Q

enzyme in the oral cavity

A

amylase: breaks down CHO (starch –> dextrin –> maltose)

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2
Q

fundus

A

upper portion of stomach that holds bulk of the food to be digested

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3
Q

most digestion in the stomach occurs where?

A

pyloric (lower) region

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4
Q

food goes from the stomach to the SI via the _____ valve

A

pyloric valve

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5
Q

complete digestion and absorption of food takes place where?

A

in the small intestine

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6
Q

order of parts in the small intestine***

A

DJI –> duodenum, jejunum, ileum

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7
Q

the ____ duct from the liver joins with the ____ duct from the gallbladder

A

hepatic duct from liver + cystic duct from gallbladder

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8
Q

bile is produced where? stored where?

A

bile produced in liver, stored in gallbladder

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9
Q

pancreas lies between the ___ & ___

A

duodenum and stomach

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10
Q

undigested food and water pass through the _____ valve into the large intestine or colon

A

ileocecal

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11
Q

most chemical or enzymatic activity for digestion occurs where?***

A

mainly in the SI

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12
Q

what chemical/enzymatic activity occurs in the stomach? what hormones?**

A

PROTEOLYSIS (protein digestion) by protease pepsin and HCl

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13
Q

what enzyme helps to break down starch?

A

amylase (in the mouth) and pancreatic amylase (in small intestine)

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14
Q

intestinal enzymes that break down CHO are?

A

sucrase, maltase, lactase (breakdown sucrose, maltose, and lactase respectively into their monosaccharides)

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15
Q

hormones: gastrin

A

gastric secretions & motility

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16
Q

hormones: CCK cholecystokinin

A

(released from duodenum when fat enters) contracts gallbladder releasing bile, stimulates pancreas

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17
Q

hormones: secretin

A

(duodenum) stimulates flow of pancreatic juice (bicarbonate) and water into duodenum, inhibits gastric acid secretion

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18
Q

hormones: glucagon-like peptide 1 (GLP-1) & GIP

A

released from intestine in presence of glucose and fat, stimulates insulin synthesis and release

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19
Q

mastication

A

produces bolus (mass of masticated food)

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20
Q

gastric emptying of a meal takes how long?

A

usually between 2-6 hours

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21
Q

rate of emptying: CHO, PRO, FAT

A
  • CHO and PRO empty from stomach at about same rate

- high fat and complex CHO slow gastric emptying

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22
Q

type of fiber that slows gastric emptying**

A

soluble fiber

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23
Q

acidic chyme enters the _____ and mixes with _____***

A

DUODENUM; MIXES with fluids and BICARBONATE IONS (from pancreas), which NEUTRALIZE acid

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24
Q

peristalsis

A

rhythmic movements of small intestine

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25
Q

enzymes for CHO digestion are available in what order?***

A
  1. maltase, sucrase
  2. lactase
  3. pancreatic amylase
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26
Q

main function of the colon?***

A

bacterial digestion

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27
Q

what does the large intestine absorb?***

A

WATER, SALTS, VITAMINS SYNTHESIZED BY BACTERIA

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28
Q

what vitamins are synthesized by bacteria?***

A

1) vitamin K
2) B12
3) thiamin
4) riboflavin

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29
Q

what happens to the vitamins that are synthesized by bacteria?***

A

USED BY GI MUCOSAL CELLS

30
Q

what is colonic salvage?***

A

anaerobic FERMENTATION and ABSORPTION of end-products of CHO, fiber, and AA absorption

31
Q

the colon converts MALABSORBED CHO & FIBERS into?**

A

SCFA + GASES (hydrogen, CO2, N, methane)

32
Q

enzymes that breakdown PRO

A

trypsin, chymotrypsim, carboxypeptidase, aminopeptidase

33
Q

simple sugars: path of absorption

A

SI –> liver –> converted to glucose or glycogen

34
Q

what % of PRO and FAT convert to glucose?***

A

58% PRO & 10% FAT

35
Q

58% of PRO converts into glucose…how?***

A

glucogenic AAs: yield glucose after deamination

36
Q

most glucogenic AA is?

A

alanine (alanine-glucose cycle)

37
Q

10% of FAT converts into glucose..how?***

A

glycerol can be converted to glucose

38
Q

can FAs and muscle glycogen contribute to the body’s source of glucose?***

A

NO- do NOT contribute to body’s supply of glucose

39
Q

uses of glucose

A

1) energy
2) storage
3) converted into other CHO compounds such as ribose

40
Q

storage of glucose occurs how?

A

1) glycogenesis: deposition of glycogen in muscle and liver

2) lipogenesis: storage in adipose tissue and liver

41
Q

function of insulin vs. glucagon***

A
  • insulin = BETA cells, fosters glycogensis and lipogenesis/storage of glucose
  • glucagon = ALPHA cells, induces glycogenolysis: breakdown of glycogen –> glucose
42
Q

glucocorticoids***

A

protein –> glucose (gluconeogenesis = creation of glucose from non-CHO sources)

43
Q

epinephrine comes from what gland?

A

adrenal gland

44
Q

epinephrine stimulates?

A

sympathetic nervous system & release of glycogen –> glucose (glycogenolysis)

45
Q

what happens during catabolic stress with epinephrine?***

A

decreases release of insulin, BLOOD GLUCOSE RISES (increased BG…sympathetic…stress…glycogenolysis)

46
Q

growth hormone and ACTH (adrenocorticotropic) are?

A

insulin antagonists

47
Q

end products of metabolism?***

A

energy, carbon dioxide, water

48
Q

where does glycolysis occur? where does Krebs/TCA cycle occur?***

A
  • glycolysis = cytoplasm

- TCA = mitochondira

49
Q

purpose of glycolysis?**

A

produce PYRUVATE for the Krebs cycle by BREAKDOWN OF GLUCOSE, with or without oxygen, into pyruvate or lactate

50
Q

aerobic glycolysis - end product?***

A

pyruvate

51
Q

anaerobic glycolysis - end product?***

A

lactate

52
Q

an intermediate of glycolysis is? coenzyme that assists?**

A

glucose-6-phosphate; magnesium

53
Q

3 pathways that can result after glucose-6-phosphate intermediate**

A

1) PYRUVATE (enters into TCA cycle (aerobic) OR converts to lactic acid (anaerobic))
2) GLYCOGEN (stored glucose)
3) ribose and NADPH

54
Q

enzyme required to turn LIVER glycogen into glucose?***

A

glucose-6-phosphatase

55
Q

do muscle cells have the enzyme glucose-6-phosphatase?***

A

NO- muscle glycogen can only be used by that muscle

56
Q

glucose-6-phosphate & the pentose shunt is AKA? what is produced? does it require ATP?***

A
  • AKA SIDE-CHANNELING OF GLUCOSE
  • PRODUCED RIBOSE & NADPH
  • DOES NOT require ATP
57
Q

NADPH has what micronutrient?***

A

niacin

58
Q

pyruvate can go on to what 2 things?***

A

1) lactic acid

2) converted to form acetyl coA

59
Q

what is lactic acid used for?***

A

MUSCLE CONTRACTIONS when ENERGY NEEDS EXCEED SUPPLY OF OXYGEN/OXYGEN DEBT (anaerobic)

60
Q

what is the Cori cycle?***

A

LACTATE is released from tissue and CONVERTED BACK TO PYRUVATE

61
Q

most of pyruvic acid is converted to form what compound?***

A

acetyl coA

62
Q

what is the MAIN substrate for energy production within the Krebs cycle?

A

pyruvate

63
Q

what things are required for the conversion of pyruvic acid to acetyl coA?***** (must name all)

A

4 vitamins & 1 mineral:

1) THIAMIN (TDP)
2) NIACIN (NAD)
3) RIBOFLAVIN (FAD)
4) PANTOTHENIC ACID (coA)
5) MAGNESIUM
6) LIPOIC ACID

64
Q

what is acetyl coA?**

A

INTERMEDIATE BREAKDOWN PRODUCT of CHO, PRO, FAT

65
Q

TCA cycle is AKA

A

Krebs cycle, citric acid cycle

66
Q

the TCA cycle produces ___% of the body’s energy as ATP***

A

90%

67
Q

what is the main fuel needed to keep the TCA cycle going?***

A

CHO

68
Q

what is the main CHO fuel of the TCA cycle? what does it react with and form to start the cycle?**

A

oxaloacetic acid (OAA) + acetyl coA –> citric acid

69
Q

how is oxaloacetic acid (OAA) formed?

A

pyruvate + some amino acids = OAA

70
Q

what happens if there is not enough OAA coming in from CHO to maintain the cycle?***

A

acetyl coA from fats cannot be handled properly, DIVERTED TO FORM KETONE BODIES OR KETOSIS

71
Q

a-ketoglutaric acid needs what for decarboxylation?

A

thiamin

72
Q

full oxidation of 1 molecule of glucose yields ___ ATP***

A

38

73
Q

a thiamin deficiency presents as?***

A

INCREASED PLASMA PYRUVATE (b/c it is a coenzyme)