Lipids - Nutrition

Question 1

categories of fatty acids

Answer 1

1. saturated
2. monounsaturated (MUFA)
3. polyunsaturated (PUFA)

Question 2

where is the caloric content of macronutrient lipids mainly fount

Answer 2

the fatty acids -> acetyl CoA and generate ATP

9 kcal/g

Question 3

different chain lengths of FA, what is the significance?

Answer 3

Long 14+ carbons
Medium 6-12 C
Short 2-4

absorbed in intestine differently

Question 4

what kinds of fats are found in what plants (generally speaking)?

Answer 4

PUFAs - plants grown in cooler areas
ie soybeans

tropical plants have higher temps of saturated fats w/o having fluidity problems

olive oil, avocados, peanuts, pecans, almonds - monounsaturated fatty acids MUFAs

Question 5

what fats are found in amimals?

Answer 5

more variability;
warm blooded - saturated fats (beef & pork)
cold water fish - polyunsat FA (esp Omega-3)

Question 6

what are fats?

Answer 6

triglycerides

dont have phosphate in them

Question 7

the importance of trans double bond vs cis?

Answer 7

trans bonds dont put a kink in the chain
so act more like saturated FA

some in meat and dairy due to bacterial fermentation

are hydrogenated to form margarine

Question 8

whats the prob w trans FA?

Answer 8

well, sat and trans unsat fatty acids raise LDL levels

trans unsat FA also lower HDL

so margarine can be worse for you than butter

Question 9

Linoleic acid

Answer 9

18:2 (n-6)

essential

Question 10

alpha-linolenic acid

Answer 10

18:3 (n-3)

essential

Question 11

arachidonic acid

Answer 11

20:4 (n-6)

derived from linoleic acid

Question 12

why are essential fa important?

Answer 12

bc they are made into prostaglandins and leukotrienes

Question 13

most of the EFA’s in the brain are…

Answer 13

linolenic (n-3)

Question 14

essential fa deficiency symptoms;

Answer 14

prominent; scaly skin (n-6 more effective for fixing)
infertility (male and female)
reduced growth rates
increased RBC fragility
etc
(rest can be fixed w either n-3 or n-6 supp)

Question 15

triene/tetraene ratio

Answer 15

EFA deficiency -> use oleat to make 20:3 n-9 a Triene

Tetraene (20:4) - eicosanoid form from n-6 and n-3

> 0.2 = EFA deficiency

Question 16

triene/tetraene ratio criterion;

Answer 16

1. geriatric, poor diet, esp w peripheral vasc disease
2. fat malabsorption
3. prolonged parenteral alimentation w formula deficient in EFAs
4. burn pts

Question 17

are EFA’s PUFAs or MUFA’s?

Answer 17

PUFAs

note; not all PUFA are essential

Question 18

DHA (docosahexaenoic acid)

Answer 18

imp constituent of breastmilk

LCFA imp for neurla development

Question 19

colipase

Answer 19

protein that anchors the pancreatic lipase to the bile acid emusified droplets to help it do its job

Question 20

monoacylglycerol (2-MG)

Answer 20

primary digestion products are this + FFA

Question 21

how are med chain triglycerides absorbed

Answer 21

directly into cells
dont need bile acids
FA bound to albumin

Question 22

how are cholesterol esters absorbed?

Answer 22

they arent
pancreatic cholesterol esterase must make it into free cholesterol
free cholesterol is absorbed after being solubilized in bile salt micelles

Question 23

how much of dietary cholesterol is excreted?

Answer 23

2/3

Question 24

describe plant sterol absorption

Answer 24

high dietary plant sterols interfere w cholesterol absorption

found in butter-replacement products

Question 25

steatorrhea

Answer 25

fatty and malodorous stools

Question 26

situations assoc w steatorrhea

Answer 26

1. pancreatic disease
2. insufficient bile production - gall bladder, cystic duct obstruction, poor liver secretion
3. loss of lrg seg of small intestine
4. damage to intestinal villae (ie celiac)
5. failure of chylomicron synthesis

Question 27

72h fecal fat test

Answer 27

greater than 7% excretion than intake = fat malabsorption

Question 28

problem w having unabsorbed digestion products like FA in the lumen of the intestine

Answer 28

interfere w absorption of various divalent cations

ie Ca, Mg, Zn

Question 29

what is most imp interms of increased incidence of atherosclerosis

Answer 29

dietary fat

far moreso than cholesterol

Question 30

___ are more atherogenic

Answer 30

saturated FA & trans FA

PUFA and MUFA are less atherogenic

Question 31

antiatherogenic

Answer 31

fish oil fatty acids (20:5 and 22:6, omega-3 PUFA)

Question 32

mediterranean diet

Answer 32

?

Question 33

homocysteine and artherosclerosis

Answer 33

correlated for inc risk for cardiovascular disease
inc in thrombosis

folate normalizes levels
B6 B12 deficiencies predispose to hyperhomocysteinemia

currently believe CV risk doesnt respond to B-vitamins