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

Question 0

food passes into stomach via the? passes through the?

Answer 0

via the esophagus, through the fundus

Question 1

enzyme in the oral cavity

Answer 1

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

Question 2

fundus

Answer 2

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

Question 3

most digestion in the stomach occurs where?

Answer 3

pyloric (lower) region

Question 4

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

Answer 4

pyloric valve

Question 5

complete digestion and absorption of food takes place where?

Answer 5

in the small intestine

Question 6

order of parts in the small intestine***

Answer 6

DJI –> duodenum, jejunum, ileum

Question 7

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

Answer 7

hepatic duct from liver + cystic duct from gallbladder

Question 8

bile is produced where? stored where?

Answer 8

bile produced in liver, stored in gallbladder

Question 9

pancreas lies between the ___ & ___

Answer 9

duodenum and stomach

Question 10

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

Answer 10

ileocecal

Question 11

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

Answer 11

mainly in the SI

Question 12

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

Answer 12

PROTEOLYSIS (protein digestion) by protease pepsin and HCl

Question 13

what enzyme helps to break down starch?

Answer 13

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

Question 14

intestinal enzymes that break down CHO are?

Answer 14

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

Question 15

hormones: gastrin

Answer 15

gastric secretions & motility

Question 16

hormones: CCK cholecystokinin

Answer 16

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

Question 17

hormones: secretin

Answer 17

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

Question 18

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

Answer 18

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

Question 19

mastication

Answer 19

produces bolus (mass of masticated food)

Question 20

gastric emptying of a meal takes how long?

Answer 20

usually between 2-6 hours

Question 21

rate of emptying: CHO, PRO, FAT

Answer 21

• CHO and PRO empty from stomach at about same rate

- high fat and complex CHO slow gastric emptying

Question 22

type of fiber that slows gastric emptying**

Answer 22

soluble fiber

Question 23

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

Answer 23

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

Question 24

peristalsis

Answer 24

rhythmic movements of small intestine

Question 25

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

Answer 25

1. maltase, sucrase 2. lactase 3. pancreatic amylase

Question 26

main function of the colon?***

Answer 26

bacterial digestion

Question 27

what does the large intestine absorb?***

Answer 27

WATER, SALTS, VITAMINS SYNTHESIZED BY BACTERIA

Question 28

what vitamins are synthesized by bacteria?***

Answer 28

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

Question 29

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

Answer 29

USED BY GI MUCOSAL CELLS

Question 30

what is colonic salvage?***

Answer 30

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

Question 31

the colon converts MALABSORBED CHO & FIBERS into?****

Answer 31

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

Question 32

enzymes that breakdown PRO

Answer 32

trypsin, chymotrypsim, carboxypeptidase, aminopeptidase

Question 33

simple sugars: path of absorption

Answer 33

SI --> liver --> converted to glucose or glycogen

Question 34

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

Answer 34

58% PRO & 10% FAT

Question 35

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

Answer 35

glucogenic AAs: yield glucose after deamination

Question 36

most glucogenic AA is?

Answer 36

alanine (alanine-glucose cycle)

Question 37

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

Answer 37

glycerol can be converted to glucose

Question 38

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

Answer 38

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

Question 39

uses of glucose

Answer 39

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

Question 40

storage of glucose occurs how?

Answer 40

1) glycogenesis: deposition of glycogen in muscle and liver | 2) lipogenesis: storage in adipose tissue and liver

Question 41

function of insulin vs. glucagon***

Answer 41

- insulin = BETA cells, fosters glycogensis and lipogenesis/storage of glucose - glucagon = ALPHA cells, induces glycogenolysis: breakdown of glycogen --> glucose

Question 42

glucocorticoids***

Answer 42

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

Question 43

epinephrine comes from what gland?

Answer 43

adrenal gland

Question 44

epinephrine stimulates?

Answer 44

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

Question 45

what happens during catabolic stress with epinephrine?***

Answer 45

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

Question 46

growth hormone and ACTH (adrenocorticotropic) are?

Answer 46

insulin antagonists

Question 47

end products of metabolism?***

Answer 47

energy, carbon dioxide, water

Question 48

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

Answer 48

- glycolysis = cytoplasm | - TCA = mitochondira

Question 49

purpose of glycolysis?**

Answer 49

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

Question 50

aerobic glycolysis - end product?***

Answer 50

pyruvate

Question 51

anaerobic glycolysis - end product?***

Answer 51

lactate

Question 52

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

Answer 52

glucose-6-phosphate; magnesium

Question 53

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

Answer 53

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

Question 54

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

Answer 54

glucose-6-phosphatase

Question 55

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

Answer 55

NO- muscle glycogen can only be used by that muscle

Question 56

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

Answer 56

- AKA SIDE-CHANNELING OF GLUCOSE - PRODUCED RIBOSE & NADPH - DOES NOT require ATP

Question 57

NADPH has what micronutrient?***

Answer 57

niacin

Question 58

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

Answer 58

1) lactic acid | 2) converted to form acetyl coA

Question 59

what is lactic acid used for?***

Answer 59

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

Question 60

what is the Cori cycle?***

Answer 60

LACTATE is released from tissue and CONVERTED BACK TO PYRUVATE

Question 61

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

Answer 61

acetyl coA

Question 62

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

Answer 62

pyruvate

Question 63

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

Answer 63

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

Question 64

what is acetyl coA?********

Answer 64

INTERMEDIATE BREAKDOWN PRODUCT of CHO, PRO, FAT

Question 65

TCA cycle is AKA

Answer 65

Krebs cycle, citric acid cycle

Question 66

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

Answer 66

90%

Question 67

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

Answer 67

CHO

Question 68

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

Answer 68

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

Question 69

how is oxaloacetic acid (OAA) formed?

Answer 69

pyruvate + some amino acids = OAA

Question 70

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

Answer 70

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

Question 71

a-ketoglutaric acid needs what for decarboxylation?

Answer 71

thiamin

Question 72

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

Answer 72

38

Question 73

a thiamin deficiency presents as?***

Answer 73

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