Metabolism-Lipids Flashcards
(26 cards)
Examples of lipids
Triglycerides, phospholipids, cholestrol
Basic building block of lipids
FA (long chain hydrocarbon organic acids
Fxn of lipids
Provide E for metabolic processes and form cell membranes.
Cis unsaturated vs trans unsaturated fat
Cis unsaturated FA has bend in structure. Found in olive oil.
-Oleic acid
Trans unsaturated FA does not have bend in structure and can get stuck to vasculature in body. Found in vegetable oils.
-Elaidic acid
Basic chemical structure of lipid
3 FA
glyceride backbone
What transports lipids from GI tract to blood? How?
Chylomicrons via lymph
Explain how lipids are absorbed into cells
Chylomicrons bring lipids to cell membrane. Cellmembranes have lipoprotein lipase (LPL) that hydrolyzes TG into FA and glycerol so they can be transported across cell membrane. Once diffused into cell, resynthesized into TG.
What can transport FA released from adipose tissue?
Albumin
What do lipoproteins transport and where are they formed and what is their fxn?
Transport cholesterol, phospholipids, TG
Lipoproteins are formed almost entirely in liver.
-Fxn=transport specific type of lipid throughout body
Describe lipoproteins
Very low density lipoproteins (VLDL)-largest
- TG
- CHOL
- PHOS
Low density (LDL)
- CHOL
- PHOS
High density (HDL)-smallest
- PROTEIN
- CHOL
- PHOS
Fxns of adipose tissue
Storage of glycerides E Insulation Cushion Endocrine organ
Fxns of liver tissue
Storage of TG, phospholipids, cholesterol
Degrade FA
Make TG and other lipids
How are TG made to ATP
1-TG hydrolyzed into FA and glycerol (enters glycolysis)
2-FA carred to mitochondria (carnitine is carrier)
3-Inside mito, FA degraded and goes through beta oxidation
4-2 C segments are released to form acetyl-CoA
5-Acetyl-CoA enters CAC and degraded into CO2 and H atoms
6-H is oxidized to make ATP
Beta oxidation of FA makes
acetyl-CoA
What does liver do w/xs acetyl-CoA?
Forms acetoacetic acid which can be made into ketone bodies
- Beta-hydroxybutric acid
- Acetone
Where do you see ketosis/ketoacidosis?
Starvation
Type I diabetes
High-fat diets
How does ketosis/ketoacidosis happen?
When peripheral tissue can’t use ketone bodies (based on decreased concentration of oxaloacetic acid) and ketons build up in the blood.
How are xs CH2O stored in adipose tissue?
As TG
Where does TG synthesis occur
Majority in liver
Some in fat cells
Overall scheme for synthesis of TG from glucose
70% glucose goes through glycolysis
- alpha-glycerophosphate can make TG
- NADH can make FA which then can make TG
30% of glucose goes through PPP
-NADPH made to make FA which then can make TG
Importance of FA synthesis (3)
- Long term E storage reserve
- Grams of glycogen vs Kg of fat
- ->1 gram fat=2.5 as much E as glycogen.
Why is insulin important?
Helps make fat and CH2O
W/o insulin, glucose would not be able to enter cells.
What are some hormones that increase release of free FA?
Epinephrine and norepinephrine
Corticotropin
Growth hormone
Thyroid hormone
Insulin
What is important to make lecithins, cephalins, and spingomyelins?
Phospholipids
