Exam #1: Lipids Flashcards
What are the roles of fatty acids?
- Texture, aroma, and flavor for food
- Structural building blocks (molecules) of cellular membranes and are the starting materials for other molecules
- Fat-soluble vitamin absorption
- Insulation, cushioning, and lubrication
- Provide energy
*Note that fat is also essential for development
How much energy comes from fat vs. carbohydrates?
Fat= 9 Cal Carb= 4 Cal
What type of fat in the body is used for energy?
Triglycerides
Describe the structure of a triglyceride.
Glycerol backbone + 3x fatty acids
Describe the structure of a phospholipid.
Glycerol backbone + 2x fatty acids + 1x phosphate group
What is a sterol?
Cholesterol/ ring structure based fat
What is the difference between saturated and unsaturated?
Saturated= no double bonds, all hydrogen
Unsaturated= some double bonding
What are the major dietary sources of saturated fat? What are the health consequences of consuming this kind of fat?
Meat, dairy, coconut palm, cocoa butter
- Increased risk of:
- CVD
- Hyperlipidemia
What are the major dietary sources of monounsaturated fat? What are the health consequences of consuming this kind of fat?
Olive oil, avocado, canola oil
- May:
- Decrease LDL
- Cardioprotective
What are the major dietary sources of polyunsaturated fat (omega-6)? What are the health consequences of consuming this kind of fat?
Corn, soy, sunflower, safflower
- Essential fatty acid
- Increases some inflammatory cytokines
What are the major dietary sources of polyunsaturated fat (omega-3)? What are the health consequences of consuming this kind of fat?
Oily ocean fish, flax seed oil, canola & soy oils
- **Essential
- Decreased TGs
- Cardioprotective
- Brain health
What are the major dietary sources of trans fat? What are the health consequences of consuming this kind of fat?
Frying and baking oils, margarine
- *****Worst for health:
- Increased LDL
- Decreased HDL
- Increased inflammatory cytokines
What enzyme is essential for the digestion of fat?
Lipase (lingual, gastric, & pancreatic)
What is the function of bile?
Pancreatic lipase rxn is highly reversible- bile keeps fat broken down
Review the process of fat absorption.
N/A
What are the consequences of lipid malabsorption?
Lipid soluble vitamin malabsorption
What is the treatment for lipid malabsorption? Why?
Medium chain fatty (8-12) acids b/c they do not require micelles or bile salts for absorption
Review the process of fat circulation in the body.
N/A
What is chyluria?
Abnormal connection between urinary tract and lymphatic drainage system
*Milky urine
What is a chylothorax?
Abnormal connection between pleural space and lymphatic drainage of small intestine
*Milky pleural effusion
What are the products of B-oxidation? Where are these products entering the TCA cycle?
Even FA= acetyl-CoA
Odd= acetyl CoA & propionyl-CoA
- Succinyl-CoA
How much total dietary fat is recommended per day?
~30g
What is the ideal ratio for omega 6 & 3 consumption?
1:1 or 1:5
*****Note that we obtain much more omega-6 in our diet than omega-3; thus, omega-3 needs to be supplemented
Aside from CAD, what diseases can be beneficially impacted by omega-3 supplementation?
Autoimmune
- Psoriasis
- RA
- Asthma
- MS
- DM-I
Depression
Dementia
What is the difference between a cis and trans fat?
Cis= natural, unsaturated fatty acid
Trans= linear & similar to saturated fatty acids
What is the argument for banning trans fat?
“Extension in shelf-life not matched by extension of human life
What are the negative effects of dietary trans fat?
Dyslipidemia Abdominal fat Systemic inflammation Endothelial dysfunction DM Membrane dysfunction
What enzymes break down alcohol in the liver?
1) Alcohol dehydrogenase
2) Acetaldehyde dehydrogenase
What are the four major metabolic effects of excess alcohol consumption?
1) Acetaldehyde toxicity
2) High NADH:NAD ratio
3) Metabolic competition
4) Induced metabolic intolerance
What are the stages of liver damage?
1) Healthy
2) Fatty
3) Fibrosis
4) Cirrhosis
What are the benefits of moderate alcohol consumption?
- Elevate HDL
- Slowed atherogenesis
- Decreased CAD
