PRELIMS LEC 2: STAGE 3 & 4 Flashcards
Citric acid cycle was first elucidated by __________
HANS KREBS
It is called the CITRIC ACID CYCLE because it refers to the first molecule/intermediate that forms during the cycle reaction which is the?
CITRATE
Protonated form of citrate?
CITRIC ACID
Citric acid cycle occurs in
MITOCHONDRIA
CITRIC ACID CYCLE/ KREBS CYCLE
is also known as _________ because of the 3 carboxyl groups of the first 2 intermediate which are the _________
TRICARBOXYLIC ACID; CITRATE AND ISOCITRATE
KREB CYCLE falls under
A ANAEROBIC CELL RESPIRATION
B AEROBIC CELL RESPIRATION
ANAEROBIC CELL RESPIRATION
KREBS CYCLE occurs in the mitochondria which uses __ molecules of _______ to produce energy
A 4, PYRUVIC ACID
B 6, PYRUVIC ACID
C 2, PYRUVIC ACID
D 3, PYRUVIC ACID
C 2, PYRUVIC ACID
KREB CYCLE products per 2 molecules of pyruvic acid
2 ATP molecules
2 FADH2 molecules
4 CO2
6 NADH molecules
reduced form of NADH and FADH2 are used in the ______ which is the stage 4 after citric acid cycle
ELECTRON TRANSPORT SYSTEM (ETS)
what do you call the process wherein carbohydrates are converted into pyruvate?
GLYCOLYSIS
what do you call the process where proteins are converted into amino acids?
PROTEOLYSIS
what do you call the process where lipids are converted into fatty acids?
LIPOLYSIS
STEPS IN KREB CYCLE/TRICARBOXYLIC ACID
- CONDENSATION AND HYDROLYSIS OF CITRATE
- ISOMERIZATION OF ISOCITRATE
- OXIDATION AND DECARBOXYLATION OF a-KETOGLUTARATE
- OXIDATION AND DECARBOXYLATION OF SUCCINYL CoA
- CLEAVAGE AND PHOSPHORYLATION OF SUCCINATE
- OXIDATION OF FUMARATE
- HYDRATION OF MALATE/L MALATE
- OXIDATION OF OXALOACETATE
(Can Intelligent Kreb Save Science From Mad Oblivion)
1ST STEP: CONDENSATION OF OXALOACETATE WILL RELEASE THE FORMING GROUP OF CoA WHICH ENABLE THE FORMATION OF _______
(C4 + C2 = C6)
A ISOCITRATE
B CITRATE
C SUCCINYL CoA
D MALATE
B CITRATE
1ST STEP: THE CONDENSATION AND HYDROLYSIS OF CITRATE IS FACILITATED BY THE ENZYME ________
A a-KETOGLUTARATE DEHYDROGENASE
B CITRATE SYNTHASE
C ISOCITRATE DEHYDROGENASE
D ACONITASE
B CITRATE SYNTHASE
IN THE 2ND STEP, CITRATE IS CONVERTED INTO ITS ISOMER (ISOCITRATE-2nd alcohol group) because CITRATE IS A TERTIARY ALCOHOL and is not readily oxidized, ISOCITRATE will make the intermediate readily oxidized.
THIS PROCESS IS FACILITATED BY THE ENZYME _______
A ISOCITRATE DEHYDROGENASE
B a-KETOGLUTARATE
C ACONITASE
D CoA SYNTHETASE
C ACONITASE
3RD STEP:
- ISOCITRATE IS OXIDIZED AND RELEASES MOLECULE OF CO2 (1st molecule Co2 produced in TCA)
- C6 to C5 forming
A a-KETOGLUTARATE
B FUMARATE
C SUCCINYL CoA
D SUCCINATE
A a-KETOGLUTARATE
3RD STEP:
- a NAD+ IS REDUCED TO FORM NADH AND THE ENZYME THAT CATALYZES THIS STEP IS
A ISOCITRATE DEHYDROGENASE
Ba-KETOGLUTARATE DEHYDROGENASE
C FUMARASE
D CoA SYNTHETASE
A ISOCITRATE DEHYDROGENASE
4TH STEP:
- a-KETOGLUTARATE IS OXIDIZED
- THEREBY REDUCING NAD+ TO NADH
- RELEASE CO2 (2nd CO2 molecule produced)
- LEFT WITH C4 (will pick up CoA group to form______)
A SUCCINATE
B MALATE
C SUCCINYL CoA
D FUMARATE
C SUCCINYL CoA
4TH STEP IS FACILITATED BY THE ENZYME
A ACONITASE
B MALATE DEHYDROGENASE
C FUMARASE
D a-KETOGLUTARATE
D a-KETOGLUTARATE
2 IMPORTANT ENZYME THAT REGULATE THE CITRIC ACID CYCLE
a-KETOGLUTARATE & ISOCITRATE DEHYDROGENASE
5TH STEP:
- CoA CONTAINED BY SUCCINYL CoA WILL REPLACED BY __________ (because Succinyl CoA is unstable - need to be stabilized)
PHOSPHATE GROUP
5TH STEP:
______ WILL SERVE AS THE DONOR OF PHOSPHATE
- it is use in some cells instead of ADP in order to form GTP as product
GDP (GUANOSINE DIPHOSPHATE/TRIPHOSPHATE)
5TH STEP:
AFTER REPLACING CoA WITH PHOSPHATE GROUP WILL FORMED __________ (which is a 4 carbon molecule)
A MALATE
B OXALOACETATE
C SUCCINATE
D FUMARATE
C SUCCINATE
5TH STEP IS CATALYZED BY THE ENZYME
A FUMARASE
B MALATE DEHYDROGENASE
C SUCCINATE DEHYDROGENASE
D SUCCINYL - CoA SYNTHETASE
D SUCCINYL - CoA SYNTHETASE
6TH STEP:
- SUCCINATE IS OXIDIZED IN 4 CARBON MOLECULE ______
- 2 HYDROGEN IONS WITH THEIR ELECTRONS ARE TRANSFERRED TO FAD PRODUCING FADH2
A FUMARATE
B MALATE
C OXALOACETATE
D CITRATE
A FUMARATE
6TH STEP:
ENZYME THAT CARRIED THE STEP FAD PRODUCING FADH2 IS EMBEDDED IN THE ……
A INNER MEMBRANE OF THE MITOCHONDRIA
B OUTER MEMBRANE OF THE MITOCHONDRIA
C SMOOTH ER
D ROUGH ER
A INNER MEMBRANE OF THE MITOCHONDRIA
FADH2 CAN TRANSPORT ITS ELECTRON DIRECTLY INTO THE
ELECTRON TRANSPORT CHAIN (ETC)
ENZYME THAT CATALYZES THE REACTION IN 6TH STEP IS THE
A SUCCINATE DEHYDROGENASE
B MALATE DEHYDROGENASE
C SUCCINYL - CoA DEHYDROGENASE
D FUMARASE
A SUCCINATE DEHYDROGENASE
7TH STEP:
- FUMARATE IS ADDED WITH WATER FORMING _____
(C4 is added with another 4 carbon molecule ___ when added with water)
A CITRATE
B OXALOACETATE
C SUCCINATE
D MALATE
D MALATE
8TH STEP
- MALATE IS CONDENSED AGAIN INTO OXALOACETATE
- IS FACILITATED BY THE ENZYME
A MALATE DEHYDROGENASE
B CITRATE SYNTHASE
C FUMARASE
D ISOCITRATE DEHYDROGENASE
A MALATE DEHYDROGENASE
7TH STEP IS FACILITATED BY THE ENZYME
A CITRATE SYNTHASE
B MALATE DEHYDROGENASE
C FUMARASE
D ISOCITRATE DEHYDROGENASE
C FUMARASE
THE PROCESS OF KREB CYCLE IS CONTINUOUS AS LONG AS THERE IS THE PRESENCE OF….
COENZYME A (CoA)
IN 1 CYCLE OF KREB CYCLE PRODUCES…
2 CARBON DIOXIDE MOLECULES
3 NADH MOLECULES
1 FADH2 MOLECULE
1 MOLECULE OF ATP/GDP
KREB CYCLE DOES NOT DIRECTLY PRODUCES ATP/GDP HOWEVER IT CAN MAKE A LOT OF ATP INDIRECTLY BECAUSE ___ AND ____ WILL ENTER THE ELECTRON CARRIERS THAT IS CONNECTED TO THE LAST STAGE OF CELLULAR RESPIRATION
3 NADH, 1 FADH2
ELECTRON TRANSPORT CHAIN AND OXIDATIVE PHOSPHORYLATION TAKES PLACE IN
MITOCHONDRIA
1
NADH AND FADH2 IS OXIDIZED TO RELEASE …
HYDROGEN IONS
2
FOLLOWING THE RELEASE OF H+ IONS INTO THE INTERMEMBRANE SPACE OF MITOCHONDRIA WILL FACILITATE THE ENERGY PRODUCTION OF ________
ATP
2 ELECTRONS THAT EXITS THE ELECTRON TRANSPORT CHAIN WILL BIND TO THE 2 FREE H IONS AND ____ OF OXYGEN MOLECULE THEREFORE PRODUCING WATER (2x happens so there are 2 H2O molecules
EQUATION:
2 H+ ions + 2 electrons + __O = H2O(x2 will bind w/ energy)
1/2
_______ is the ultimate receiver in ETC
- it is estimated that 95% of _____ used by cells serve as the final electron acceptor for the ETC.
OXYGEN
WHEN H IONS ARE GONE TO ATP SYNTHASE, ADP (Adenosine diphosphate) WILL BE CONVERTED INTO ___
ATP (ADENOSINE TRIPHOSPHATE)
________ FACILITATES THE PROCESS OF ELECTRONS WHICH IS TRAPPED IN NADH AND FADH2 MOLECULE DURING TCA CYCLE
- IT IS A SERIES OF BIOCHEMICAL REACTION IN WHICH INTERMEDIATE CARRIERS AID THE TRANSFER OF ELECTRONS AND H IONS FROM NADH & FADH2
- IS NAMED BECAUSE OF THE FACT THAT ELECTRONS ARE TRANSFERRED TO OXYGEN VIA RESPIRATION
ELECTRON TRANSPORT CHAIN
ELECTRON TRANSPORT CHAIN IS AN _______________
A ANAEROBIC CELLULAR RESPIRATION
B AEROBIC CELLULAR RESPIRATION
B AEROBIC CELLULAR RESPIRATION
It is estimated that _______ of the oxygen used by cells serves as the final electron acceptor for the electron transport chain.
95%
This is the process where your ADP molecule + inorganic phosphorus
OXIDATIVE PHOSPHORYLATION
these are pairs of biochemical reactions that occur concurrently in which energy released by one reaction is used in the other reaction.
COUPLED REACTIONS
For every 2 electrons that pass through the electron transport chain:
✓ 4 protons cross the inner mitochondrial membrane through complex 1.
✓ 4 through complex 3
✓ 2 through the complex 4
they serve as proton pumps
Complexes 1,3 and 4
how many moles of ATP are formed for each mole of NADH oxidized in the electron transport chain?
2.5
how many moles of ATP are formed for each mole of FADH2 oxidized in the electron transport chain?
1.5
how many moles of ATP are formed for each mole of GTP oxidized in the electron transport chain?
1
how many ATP is produced for each Acetyl Coenzyme A that is metabolized by your citric acid cycle.
10
3 NADH x 2.5
1 FADH2 x 1.5
1 GTP x 1
= 10
