I N: Metabolism of PRO & FAT

Question 0

what are the branched chain amino acids?

Answer 0

valine, leucine, isoleucine

Question 1

___ is needed for the transport of amino acids

Answer 1

pyridoxine

Question 2

during exercise, oxidation of what AAs increase?

Answer 2

alanine and leucine

Question 3

_______ can be synthesized from phenylalanine; ________ from methionine

Answer 3

phenylalanine –> tyrosine

methionine –> cysteine

Question 4

what does nitrogen balance measure?

Answer 4

body equilibrium - compares intake to output

Question 5

N balance: 0 balance

Answer 5

maintenance, nitrogen equilibrium

Question 6

N balance: + balance

Answer 6

NET GAIN of protein = infant, teenager, pregnancy, healing

Question 7

N balance: negative balance

Answer 7

erosion of body protein; inadequate intake

Question 8

Nitrogen balance formula***

Answer 8

(protein intake in grams / 6.25) - (urinary urea nitrogen + 4)

Question 9

methods to determine protein quality

Answer 9

1) biological value (BV)
2) net protein utilization (NPU)
3) PDCAAS (protein digestibility corrected amino acid score)

Question 10

what is biological value?

Answer 10

uses N BALANCE to determine FRACTION OF ABSORBED NITROGEN

Question 11

eggs have a BV of?

Answer 11

100% = all the nitrogen absorbed is retained

Question 12

what is net protein utilization?

Answer 12

measures the amount of protein ACTUALLY USED

Question 13

what is PDCAAS?

Answer 13

(protein digestibility corrected amino acid score)

estimates % of protein in each food category that is ACTUALLY DIGESTED

Question 14

plant vs. animal proteins

Answer 14

protein from animal products is generally better used and digested than that from plants

Question 15

anabolism of DNA

Answer 15

DNA forms RNA on ribosomes, which forms the template which carries the plan to the cytoplasm

Question 16

catabolism of proteins: what AA is involved?**

Answer 16

pyridoxine

Question 17

first step of catabolism in proteins?***

Answer 17

deamination- splitting off of NH2 by hydrolysis in liver

Question 18

after deamination of proteins, what happens?**

Answer 18

1) NH2 –> NH3/ammonia, toxic

2) keto acid –> oxidized for energy

Question 19

what happens to the NH3/ammonia?**

Answer 19

1) UREA –> EXCRETED BY KIDNEYS = WASTE
2) purine –> uric acid
3) transamination to make NEW AA (non-essential ones)

Question 20

what is deamination?

Answer 20

splitting off of NH2 by hydrolysis in liver

Question 21

what is transamination?

Answer 21

transfer of amino group to a keto acid to form a new AA

Question 22

hormones involved in protein anabolism

Answer 22

pituitary growth hormone, thyroid, insulin, testosterone

Question 23

hormones involved in protein catabolism

Answer 23

adrenal steroids (glucocorticoids = protein –> glucose) stimulate gluconeogenesis (creation of glucose from non-CHO sources)

Question 24

end products of fat digestion are?

Answer 24

monoglycerides, diglycerides, glycerol, fatty acids

Question 25

what fat products from digestion are directly absorbed into the portal blood?

Answer 25

1) glycerol 2) SCFA (<12 Cs) 3) some phospholipids

Question 26

monoglycerides, diglycerides, LCFA combine with bile salts to form what?

Answer 26

micelles

Question 27

micelles bind to protein to form ________?

Answer 27

LIPOPROTEINS (chylomicron), which penetrate intestinal mucosa, travel through lymph, into the thoracic duct into the blood

Question 28

how is cholesterol absorbed?

Answer 28

some w/ bile salts; MOST with CHOLESTEROL ESTERASE

Question 29

how is cholesterol excreted?***

Answer 29

by LIVER as BILE

Question 30

what is lipogenesis? 2 forms?

Answer 30

synthesis or deposition of fat; can be via adipose tissue or the liver

Question 31

adipose tissue lipogenesis- what occurs?

Answer 31

most ACTIVE site: FA + glycerol --> TGs (needs NADPH)

Question 32

liver lipogenesis- what occurs?

Answer 32

liver synthesizes fat, but should NOT store it

Question 33

how can fat accumulation be prevented in the liver?

Answer 33

lipotropic factors (choline) produce lipoproteins which transfer FA out of the liver

Question 34

what is lipolysis?

Answer 34

oxidation of fats --> forms acetyl coA which enters Krebs cycle to be broken further into ENERGY

Question 35

hormones for lipogenesis

Answer 35

insulin (anabolic)

Question 36

hormones for lipolysis: insulin antagonists

Answer 36

growth hormone, glucagon

Question 37

glucocorticoids, thyroxine, epinephrine, and ACTH are all hormones that do what?

Answer 37

increase rate of fat mobilization

Question 38

normal fat metabolism requires what for complete fat oxidation?***

Answer 38

CARBOHYDRATES

Question 39

what occurs in abnormal fat metabolism?***

Answer 39

INADEQUATE CHO = incomplete fat oxidation & BUILDUP OF KETONES --> buildup of acetyl coA as there is NO OAA to combine with it

Question 40

active transport is used to transport what nutrients?****

Answer 40

MOST NUTRIENTS (glucose, AA, Na, K, Mg, Ca, FE)

Question 41

what is an example of active transport?***

Answer 41

sodium pump

Question 42

what does a sodium pump do?***

Answer 42

form of active transport: uphill pumping from LOWER TO HIGH concentration across a membrane AGAINST AN ENERGY GRADIENT (need ATP)

Question 43

what is simple diffusion? what is transported via it?

Answer 43

higher to lower concentration, intestine to blood to lymph; some water and electrolytes

Question 44

what is carrier-facilitated passive diffusion? what is transported via it?***

Answer 44

HIGHER TO LOWER CONCENTRATION; WATER-SOLUBLE NUTRIENTS

Question 45

factors that aid in vitamin A, D, E/K absorption

Answer 45

- A = bile salts, pancreatic lipase, fat - D = bile salts, acidity of chyme, accompanies Ca and P absorption - E, K = bile salts, fat

Question 46

factors that aid in thiamin absorption

Answer 46

acid

Question 47

factors that aid in riboflavin absorption

Answer 47

phosphorous

Question 48

factors that aid in B12 absorption

Answer 48

ileum, stomach secretions (HCl, IF)

Question 49

factors that aid in calcium absorption

Answer 49

acid, vitamin D, lactose

Question 50

factors that aid in iron absorption**

Answer 50

HCl, calcium (binds oxalates)

Question 51

central regulation of food intake is via what gland?***

Answer 51

hypothalamus gland

Question 52

what are glucoreceptors?***

Answer 52

thought to regulate desire to eat

Question 53

other functions of hypothalamus gland

Answer 53

- satiety and feeding center | - regulates body temperature