Lecture Slides - Lipids I

Question 1

Dietary Lipids = _____ _____

Answer 1

Fatty Acids

Question 2

Saturated fatty acids are in ____ form at room temperature

Answer 2

solid

Question 3

Unsaturated fatty acids are in ____ form at room temperature

Answer 3

liquid

Question 4

Are fats/oils composed of saturated or unsaturated fatty acids?

Answer 4

both!

Question 5

What is the degree of saturation in saturated fatty acids?

Answer 5

single carbon bonds - all carbon bonds are saturated

Question 6

Describe a monounsaturated fatty acid structure in terms of bonds?

Answer 6

there is one double bond ( C=C )

Question 7

Describe a polyunsaturated fatty acid structure in terms of bonds?

Answer 7

there is greater than two double bonds ( >2 C=C )

Question 8

What does the ‘3’ in “omega-3” tell you about the structure?

Answer 8

tells you where the first double bond is located - it is the 3rd carbon from the omega end

Question 9

In what product are omega-6 polyunsaturated fatty acids generally found?

Answer 9

vegetable oils

Question 10

Every C=C creates an opportunity for what to occur? Why is this bad?

Answer 10

Degree of saturation matters, for every C=C there is an opportunity for oxidation - this can be bad if it is happening outside the mitochondria

Question 11

What happens when you cook with olive oil?

Answer 11

You destroy the aromatics (nice smell) and char the phytochemicals

Question 12

most butter is __% oil and fat, what is the rest of it?

Answer 12

80%

20% = water or protein

Question 13

What does it mean to “clarify” butter?

Answer 13

removing the water

Question 14

How are large lipid droplets in the small intestine digested?

Answer 14

Bile acids emulsify fat into smaller droplets, then lipase released from pancreas breaks down fat into fatty acids, diacylglycerols and monoacylglycerols, then absorption through villi via micelles happens

Question 15

Where do bile acids for fat digestion come from?

Answer 15

the gallbladder

Question 16

2 characteristics of micelle that we discussed?

Answer 16

hydrophobic heads and hydrophilic tails

Question 17

Micelles act as ____

Answer 17

ferries

Question 18

most of the fats we consume are _____ chain

Answer 18

long

Question 19

What three things are in a Chylomicron?

Answer 19

• TAG
• cholesterol
• phospholipids

Question 20

Fats are moved into the blood using ____

Answer 20

chylomicron

Question 21

Why is medium/short chain fatty acid transport less dependant?

Answer 21

They don’t require a channel, they can travel independently

Question 22

Chylomicrons move their contents to the _____

Answer 22

lymph

Question 23

What types of fats doe micelle transport?

Answer 23

long chain

Question 24

Medium/short chain fatty acids end up where?

Answer 24

hepatic portal vein

Question 25

Coconut oil is an example of what type of fatty acid?

Answer 25

medium chain

Question 26

Fatty acids can be used in the muscle to produce what? What part of the muscle cell does this?

Answer 26

ATP; mitochondria

Question 27

When IMTG creates fatty acids at the muscle, what is a byproduct and where does it go?

Answer 27

glycerol - goes into the blood then into the liver

Question 28

What does lipoprotein lipase do to the very-low-density lipoproteins?

Answer 28

it is an enzyme that cleaves off fatty acids from the glob of glycerol so that they can be used

Question 29

What happens if LPL is not functioning properly?

Answer 29

VLDL will accumulate in the blood = not good

Question 30

In the muscle, where are the lipid droplets with regard to the mitochondria?

Answer 30

They are right beside them! This is so it has access to energy stores.

Question 31

How does oxidation of medium chain fatty acids and long chain fatty acids differ when in a fasted vs non-fasted state (fed with glucose)?

Answer 31

``` MCFA -fasted = 99% -glucose cond = 98% -virtually no impairment LCFA -fasted = 86% -glucose cond = 70% -reduction in fat oxidation is apparent ```

Question 32

"disease in which plaque builds up inside your arteries"

Answer 32

atherosclerosis

Question 33

What is plaque made up of?

Answer 33

fat, cholesterol, calcium, inflammatory immune factors

Question 34

_____ occurs mainly by the effect of several reactive oxygen species (eg. hydrogen peroxide), and can also be generated by the action of phagocytes

Answer 34

oxidation (lipid peroxidation)

Question 35

What did the Framingham Heart Study (1961) reveal?

Answer 35

high serum cholesterol was a major risk factor for coronary heart disease - it became widely accepted that dietary saturated fats increased serum cholesterol

Question 36

Omega-_ PUFA is inflammatory while Omega-_ PUFA is anti-inflammatory.

Answer 36

6 ; 3

Question 37

Safflower, sunflower, corn, soybean, canola, peanut, walnut, and cottonseed oil are all examples of Omega-_ PUFA

Answer 37

6

Question 38

Fish and flaxseed are examples of Omega-_ PUFA

Answer 38

3

Question 39

In the current "western" diet, what is the ratio of N-6 to N-3?

Answer 39

15:1 or 16.7:1 Until about 150 years ago, this ratio used to be 1:1

Question 40

What are the implications for health of a high N-6 to N-3 ratio?

Answer 40

``` CV disease cancers osteoporosis inflammatory disease autoimmune disease ```

Question 41

An increase in dietary intake of N-6 PUFAs leads to oxidation of ____ , _____ aggregation, and it interferes with the incorporation of what?

Answer 41

LDLs; platelet; essential fatty acids in cell membrane phospholipids

Question 42

When plaque forms, part of it is due to a bad feedforward system. What is this system?

Answer 42

When the endothelium is damaged due to oxidation, there are small tears that occur - the body responds with platelets, sending clotting factors and immune response to the area - these components contribute to plaque build up

Question 43

Omega-3 fatty acids suppress interleukin 1B. What do these interleukins do?

Answer 43

They are responsible for immune response - they repair damaged cells

Question 44

Omega-3 fatty acids have tumor necrosis factor-a. What does TNF do?

Answer 44

target tumor cells and break them down - interfering with this may contribute to cancer formation

Question 45

Genetic defects in LDL receptors of people with familial ________

Answer 45

hypercholesterolemia

Question 46

LDL and VLDL is heavily influenced by ____

Answer 46

genetics

Question 47

"reverse-cholesterol transport, bringing cholesterol from arterial deposits to the liver for processing - converted to useful metabolites and eventually cleared form the body via bile secretions"

Answer 47

HDL

Question 48

____ is talking about the genetic variant of the LDL receptor

Answer 48

LPA

Question 49

_____ density lipoproteins are the "good cholesterols"

Answer 49

high

Question 50

_____ are responsible for transport, they are like a scavenger that gathers and removes things from blockages and brings them back to the liver

Answer 50

HDL

Question 51

When N-6 PUFA are oxidized they generate _____ substances

Answer 51

antigenic

Question 52

antigenic substances created from the oxidization of N-6 PUFA are recognized by ______ and cause what type of response?

Answer 52

interleukins; inflammatory response

Question 53

Why can consuming antigenic substances have a negative influence on immune response?

Answer 53

Consuming antigenic substances has immune response last 5-15 days - you don’t get this same response every time, if you get a second exposure then you get a much larger immune response (especially if you have antibodies too - like from a cold) - the bodies response is heightened every time and is worse as you have more exposure

Question 54

What type of proteins do N-6 PFUS interfere with?

Answer 54

sterol regulatory element binding proteins

Question 55

What do SREBPs do?

Answer 55

-move to the nucleus in cholesterol-depleted cells to alter transcription of several genes involved in lipid metabolism, which results in increased serum cholesterol

Question 56

SREBPs are implicated in the metabolism of ______ cells

Answer 56

cancerous

Question 57

N-6 PUFA make LDL more susceptible to what?

Answer 57

- lipid peroxidation | - subsequent deposition of the oxidized LDL in macrophages lining the arteries

Question 58

_____ fats are not susceptible to lipid peroxidation and have not been found to be involved in the mechanisms affecting serum cholesterol.

Answer 58

saturated

Question 59

Oxidative stress and lipid peroxidation products are known to promote what?

Answer 59

Heart disease, cancer, and several other chronic diseases

Question 60

Cooking at high temperatures in traditional sources of SFAs converts PUFA and CHO's to disease promoting _____ ______

Answer 60

oxidation products

Question 61

Sugars readily undergo oxidation to products: - - -

Answer 61

- glyoxal - methylglyoxal - formaldehyde

Question 62

Methlglyoxal has been shown to promote what 4 things?

Answer 62

1. Endothelial dysfunction 2. Hypercholesterolemia 3. Atherosclerosis 4. Hypertension

Question 63

Formaldehyde and Methylglyoxal have been implicated in what 3 things?

Answer 63

- Endothelial injury - Oxidative Stress - Angiopathy (damage to blood vessels)

Question 64

What two factors should you consider when choosing a fat?

Answer 64

1. how is it being used | 2. can you manage the risk

Question 65

When something says "fat-free" what does this usually mean?

Answer 65

it often has large amounts of added sugar to make it more palatable

Question 66

Young children who consumed more fruit juice than their peers were what?

Answer 66

shorter in stature and had greater BMI

Question 67

____ is more strongly associated with obesity than dietary fat

Answer 67

HFCS - high fructose corn syrup

Question 68

Solutions of fructose are highly susceptible to _____, producing toxic products.

Answer 68

autoxidation

Question 69

____ is highly resistant to oxidation

Answer 69

sucrose