Beta Oxidation Flashcards
Beta oxidation of lipids
- called beta oxidation because the oxidation and splitting of ________ atoms occur at the ____ carbon
- occurs in the ______
2 carbon
beta
mitochondria
PREPARATIVE STAGES of beta oxidation
(1) fatty acids are activated to their ___ forms in the _______
(2) ___________________ CoA can’t pass through the _____ membranes therefore a transporter called _____ help
CO-A ; cytoplasm
long chain fatty acyl ; inner mitochondria; carnitine
PREPARATIVE STAGES of beta oxidation
(3) _____ transfers the fatty acyl to the ____ group of the ____ to form ________
Occurs in the cystolic side of ____
Carnitine acyl transferase 1(CAT1)
hydroxyl
carnitine
acyl carnitine. ; IMM
PREPARATIVE STAGES of beta oxidation
(4)______ carries the acyl carnitine through the membrane to the _____. Then ___ transfers the ___ group back to the coenzyme.
translocase
matrix
CAT2
acyl
At the end of the PREPARATIVE STAGES of beta oxidation
Carnitine goes back to the _____ side
cystolic
BETA OXIDATION STEPS
(1) ________________
(2) ________
(3) __________
(4) ________
FAD linked Dehydrogenase
Hydration
NAD+ dependent state
Cleavage
BETA OXIDATION STEPS
(1) FAD linked Dehydrogenase o
- fatty acyl coA is dehydrogenated to _______ (unsaturated)
- ___ to ____
- ________________ enzyme
(2) Hydration
- ___________ to ______
- __________
(3) NAD+ dependent state
- _______ is oxidized to ______
- ______ is formed
(4) Cleavage
- __________ undergoes ____ Cleavage to give ______ and a fatty acyl coA with __ carbon less
transenoyl coA: FAD to FADH2; acyl coA dehydrogenase
transenoyl coA to beta hydroxy fatty acyl coA
; enoyl coA hydratase
beta hydroxy fatty acyl co A ; beta keto fatty acyl coA; NADH
beta keto fatty acyl coA ; thiolytic
acetyl coA ; 2
_______ inhibits CAT-I activity.
Malonyl CoA
The odd chain fatty acids are oxidised exactly in the same manner as even chain fatty acids. However, after successive removal of 2-carbon units, at the end, one ____-carbon unit, _____ is produced
3
propionyl CoA
Proprionyl coA is converted to ______ then enters TCA cycle, finally converted to _____, and is used for _____ pathway .
succinyl CoA
oxaloacetate
gluconeogenesis
DE NOVO SYNTHESIS OF FATTY ACIDS
The pathway is referred to as ______.
It (is or is not?) a reversal of oxidation.
Lynen’s spiral
Not
Fatty acids are synthesized mainly by a _______ pathway operating in the _____.
So it is referred to as extramitochondrial or cytoplasmic fatty acid synthase system.
de novo synthetic
cytoplasm
The starting material for de novo synthesis is ______ that is formed inside the _____ from _____.
the acetyl CoA units are delivered to the cytoplasm as ____ that is transported from mitochondria by a tricarboxylic acid transporter.
In the cytoplasm, citrate is cleaved to ______ and _____ . The enzyme is _________
The oxaloacetate can return to the mitochondria as ______ or ______
acetyl CoA
mitochondria
pyruvate
citrate
oxaloacetate and acetyl CoA
ATP citrate lyase.
malate or pyruvate
The inner membrane of mitochondria is freely permeable to acetyl CoA.
T/F
F it’s
not freely permeable to acetyl CoA.
citrate is an allosteric (stimulator or inhibitor ?) of acetyl coA carboxylase
palmitoyl coA (stimulates or inhibits?) acetyl coA carboxylase
Stimulator
Inhibits
In de novo synthesis of fatty acids
Acetyl CoA to ______
- ______ is required
- ______________ is the rate limiting enzyme
Acetyl coA to acetyl SH CE
- acetyl ______
- transfer of ___ to the ______ enzyme molecule
Malonyl coA to malonyl SH ACP
- malonyl ____
- transfer of _____ to __ by ____
malonyl Co A
biotin
acetyl Co A carboxylase
transcyclase; acetyl; SH condensing
transcyclase; malonyl; S; ACP
Now, de novo synthesis gan gan
A+ M = _______ ACP/_______ ACP
- _C + _C combine and condense and __ is let out
- condensing enzyme /_______
______ to _______
- _____ reaction
- _______ is used
- ________________
- ________ to _______
- ______ reaction
- _______
______ to ____
- _______ enzyme
- second molecule of nadph is used
Pass on butyryl (4C) to the ___ of ____ of another monomer an pick up another malonyl coA and repeat the sequence from condensation to reduction again . For palmitate, it does it seven times
______ to ______
- _______ releases palmitate from the multi enzyme complex
- palmitate ends up in liver and adipose tissue
- breast is ____(10C) and _____(12C)
aceto acetyl ; beta keto acyl
2;3 ; co2; keto acyl synthetase
Aceto acetyl ACP=beta hydroxy butyryl ACP; reduction; 2 NADPH ; beta keto acyl reductase
beta hydroxy butyryl ACP to Enoyl ACP ; dehydration; dehydratase
Enoyl ACP to butyryl ACP; Enoyl reductase
SH of condensing enzyme
Butyryl ACP to palmitate; thio esterase
capric; lauric
The acetyl CoA formed from fatty acids can enter and get oxidized in TCA cycle only when _____ are available.
During _____ and ____ , the acetyl CoA takes the alternate fate of formation of ketone bodies.
carbohydrates
starvation and diabetes mellitus
________ is the primary ketone body while _____________ and ________ are secondary ketone bodies.
They are synthesised exclusively by the _________.
Acetoacetate
beta-hydroxy butyrate and acetone
liver mitochondria
Ketogenesis
Step 1. Condensation :___ molecules of _____ are condensed to form _____
Step 2.
One more ____ is added to ____ to form _______ . The enzyme is ________.
Step 3. Lysis
Then ______ is lysed to form _____.the _____ enzyme is used
Step 4. Reduction
_________ is formed by reduction of ____.
Step 5.
By _______, ______ is formed
Two; acetyl CoA ; acetoacetyl CoA.
acetyl CoA; acetoacetyl CoA; HMG CoA ; HMG CoA synthase
HMG CoA ; acetoacetate; HMG CoA lyase
Beta-hydroxy butyrate; acetoacetate
Spontaneous decarboxylation ; acetone
Full meaning of HMG CoA
beta hydroxy beta methyl glutaryl CoA
_______ HMG CoA is used for ketogenesis, while _____ fraction is used for cholesterol synthesis.
Mitochondrial
cytosolic
HMG CoA lyase is present in few organs
T/F
F
It’s only in 1 organ, the liver
Ratio between acetoacetate and beta hydroxy butyrate is decided by the cellular ___:____ ratio.
NAD:NADH
Ketolysis
The ketone bodies are formed in the _____; but they are utilised by ______ tissues.
The ____ muscle and_____ prefer the ketone bodies to glucose as fuel.
Tissues like ____ muscle and ____ can also utilise the ketone bodies as alternate sources of energy, if glucose is not available.
_________ is activated to _____ by ____ enzyme and then it enters the ______ pathway to produce energy.
liver
extrahepatic
heart ; renal cortex
skeletal; brain
Acetoacetate; acetoacetyl CoA; thiophorase
beta oxidation
___________ is the most common cause for ketosis.
Uncontrolled diabetes mellitus
TAG synthesis
in liver it’s by _______
in adipose tissue, it’s by _______ gotten from _____ because adipose tissues lack _____
glycerol 3 phosphate
dihydroxylacetone phosphate; glycolysis
glycerol kinase
TAG synthesis in adipose tissue
(1) ________ to _______
- _____________
(2) _______ to _______
- ______ enzyme
- ______ is used
(3) ________ to ____
- _______
(4) ________ to _________
- _______
(5) __________ to ______
- __________
Dihydroxyacetone phosphate - acyl dihydroxyacetone phosphate ; acyl transferase
Acyl dihydroxyacetone phosphate to lysophosphatidic; reductase; nadph
Lysophosphatidic to phosphatidic; acyl transferase
Phosphatidic to 1,2di acyl glycerol; phosphatidate phosphatase
1,2di acyl glycerol to triacylglycerol; acyl transferase
