Fatty acid degradation
9 important questions on Fatty acid degradation
What are the 4 functions of fatty acid?
- Building blocks
- phospholipids and glycolipids constituents of membrane
- Targeting
- bind to protein directing them to designated location in membrane
- Messengers
- serve as hormones and intracellular messenger molecules
- Energy
- stored as triacyglycerols (TAG)
What is the structure of triglycerides? Where are they stored?
- glycerol is the hook where the fatty acid are attached to
- stored in fat cells/lipid droplets, called adipocytes
How are triglycerides (fat) taken up from the food?
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
What are the steps when fat is being burned due to fasting/hunger state?
- Mobilization
- Activation and transport
- Degradation
How are long fatty acids (>C20) degraded?
- first step of fatty acid degradation in peroxisome, which is catalyzed by a FAD containing dehydrogenase, the electrons are directly transferred to molecular oxygen to yield hydrogen peroxide H2O2
- electrons are lost and will produce less ATP in the later TCA cycle
- H2O2 is degraded by catalase in H2O and O2
- The remaining of the reaction are the same
- peroxisome have no TCA cycle, the formed acetyl-CoA is transported to mitochondria for degradation to CO2 and H2O
What happens when a fatty acid degradation occurs with an odd number of carbon atoms?
- Propionyl-CoA is converted into succinyl-CoA (C4-CoA), which is an intermediate of the TCA cycle and can be converted into oxaloacetate (C4) to make glucose
- Propionyl-CoA carboxylase
What happens when a fatty acid degradation occurs which is unsaturated?
for odd carbon atom
- isomerase: shifts the position of the double bond from an odd carbon atom to a even carbon atom.
for even carbon atom
- isomerase
- reductase
Each unsaturated fatty acid can be completely degraded with only 2 additional enzyme
What is the use of ketone bodies?
How are ketone bodies formed and where?
- Only in liver
- are formed from acetyl-CoA when fat breakdown predominates used as a source of energy in the body
- Acetoacetate(C4) can be converted to acetyl-CoA and is an important fuel in some tissues (heart muscle, skeletal muscle, brain)
- 2 acetyl groups attached to each other
- can be converted to acetyl-CoA
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding