L5+7 Biochem Flashcards
also known as Embden-Meyerhof Pathway or Embden– Meyerhof-Parnas Pathway
Glycolysis
Aerobic Glycolysis:
1-end product is ___
2-cells have ____ and ___
1- Pyruvate
2-mitochondria and oxygen
Anaerobic Glycolysis:
1-end product is ____
2- allows the production of ATP in cells that don’t have ____ and ___
3-e.g happens in ____ and ____
1- Lactate
2-mitochondria and oxygen
3-RBC and exercising muscle
entry of glucose into cells happens using carriers:
1-____: for muscle cells, heart cells, adipocytes (insulin-dependent)
2-___ : for liver cells, kidney (insulin-independent)
3-___ : for neurons (insulin-independent)
4-___ : for RBCs, brain (insulin-independent)
–
all enzymes required for glycolysis are present in the ______
1- GLUT4
2-GLUT2
3-GLUT3
4-GLUT1
–
CYTOSOL
A) Energy investment/Preparatory Phase:
- reactions from 1-5
1- glucose to _________ , __ ATP were invested
B) Energy Payoff Phase:
-reactions from 6-10
1- two glyceraldehyde 3-phosphate molecules to __________ plus ___ ATP molecules.
A1- two glyceraldehyde 3-phosphate molecules, two
–
B1- Two Pyruvate PLUS four ATP
Aerobic glycolysis 1st reaction:- 1-substrate: glucose 2-****enzyme: \_\_\_\_\_ 3-end product: \_\_\_\_\_ 4- ATP to \_\_\_
2-Hexokinase OR (glucokinase for hepatocytes)
3-Glucose 6-phosphate
4- ADP (energy-consuming)
Aerobic glycolysis 2nd reaction:- 1- substrate:glucose 6-phosphate (aldose) 2- enzyme: \_\_\_\_\_ 3- end product: \_\_\_\_\_
2- Phosphoglucose isomerase
3- Fructose 6-phosphate (ketose)
Aerobic glycolysis 3rd reaction:- 1-substrate: Fructose 6-phosphate 2- ****enzyme: \_\_\_\_\_ (allosteric/regulatory) 3- end product: \_\_\_\_\_ 4- ATP to \_\_\_
2- Phosphofructokinase-1
3-Fructose 1-6-bisphosphate
4- ADP (energy-consuming)
Aerobic glycolysis 4th reaction:- 1-substrate: Fructose 1-6-bisphosphate 2- enzyme: \_\_\_\_\_ 3- end product: \_\_\_\_\_
2- Aldolase
3- one molecule of Glyceraldehyde 3-phosphate
one molecule of Dihydroxyacetone phosphate
Aerobic glycolysis 5th reaction:- 1-substrate: Dihydroxyacetone phosphate 2- enzyme: Trios phosphate isomerate 3- end product: \_\_\_\_\_
Glyceraldehyde 3-phosphate
Aerobic glycolysis
6th reaction:- (substrate-level phosphorylation)
1-substrate: Glyceraldehyde 3-phosphate
2-*** enzyme: ___
this enzyme has 2 functions that are
a. Adding one Pi to C1 (~high energy bond)
b. Oxidation/dehydration (needs H+ carrier called NAD)
3-end product:______ ~high energy~
along with NADH + H
2- Glyceraldehyde 3-phosphate dehydrogenase
3- 1,3-Bisphosphoglycerate
Aerobic glycolysis 7th reaction:- (substrate-level phosphorylation) 1-substrate: 1,3-Bisphosphoglycerate 2- enzyme: \_\_\_\_\_ 3-end product: 3-Phosphoglycerate 4- from ADP to \_\_
2- Phospho-glycerate kinase
4- ATP (energy releasing)
A- Aerobic glycolysis results in __ ATP, 2 ___ and ___ NADH
B- Anaerobic glycolysis (in RBC/exercising muscle/cornea)
results in :
1- if NO 2,3-BPG is formed: __ ATP
2- if 2,3-BPG is formed: __ ATP
A- 8 ATP, 2 pyruvate, 2 NADH
B- 2 , ZERO
Inhibitors of glycolysis:
***1- ____: inhibits glyceraldehyde-3-phosphate by replacing Pi at C1, leads no net production of ATP
2- ____: inhibits glyceraldehyde-3-phosphate
3- ____: inhibits Enolase to decrease dental caries (lactic acid from bacteria)
1- Arsenate
2- Iodoacetate
3- Flouride
Regulatory enzymes (glycolysis):
1- Glucokinase/hexokinase
***2-_____
3-pyruvate kinase
2-PFK-1
Regulatory Mechanisms (glycolysis): A) \_\_\_\_\_\_\_\_: a1-Allosteric b1-Covalent modifications B) \_\_\_\_\_\_\_\_: b1-Induction by \_\_\_\_/repression by \_\_\_\_
A- Rapid, short term
B- Slow, long term
b1-insulin (stimulation), Glucagon (inhibition)
Effect of hormones on glycolysis:
1) Insulin: ____ the synthesis of the 3 irreversible enzymes.
a. _____ (activates) the enzymes through activation of protein phosphatase
2) Glucagon: ____ the synthesis of the 3 irreversible enzymes.
a. ______ (inactivates) the enzymes mediated by cAMP activation of protein kinase
1) Induces
a. dephosphorylates
- -
2) Represses
a. phosphorylates
1-_____:
-high affinity (low Km), it is active at low glucose concentration
2-____:
- low affinity (high Km) only active at high glucose concentration.
- found in Liver Only
1- Hexokinase
2-Glucokinase
regulation of PFK-1 ***:
- inhibited allosterically by ATP and _____
- stimulated by AMP and ________
- ATP and Citrate
- Fructose 2,6-bisphosphate
indicator of high energy state?
High citrate (product of citric acid cycle)
it is formed from fructose 6-phosphate by phosphofructokinase-2 (PFK-2)
Fructose 2-6 bisphosphate
- during well-fed state, elevated levels of ____
Insulin
regulation of pyruvate kinase (PK)
- Feedforward regulation by _________ (the product of PFK-1)
- covalent modification by PK
**Q. if PK was NOT able to function?
1- Fructose 1,6- bisphosphate
A. there will be accumulation of PEP (phosphoenolpyruvate)
importance of Glycolysis:
1- ___ _____: under aerobic and anaerobic conditions
2-importance of glycolytic intermediates:
2a. pyruvate in making:
- ____(citric acid cycle and gluconeogenesis)
- ____
2b. _____is very important in lipid biosynthesis
3- synthesis of non essential protein
3a. 3-phosphoglycerate—> ___
3b. pyruvate—>___
1- energy production
2a.
- Oxaloacetate (the prime of krebs cycle)
- Acetyl CoA
- -
2b. Dihydroxyacetone phosphate (DHAP) - -
3a. Serine
3b. Alanine
PK deficiency is resricted to RBCs and produces mild to severe _______
Chronic hemolytic anemia
fate of \_\_\_\_\_ : 1- Lactate 2-Alanine 3-oxaloacetate 4-Acetyl Coa
Pyruvate
formation of alanine (cytosol)
substrate: Pyruvate
enzyme: ALT (alanine transaminase)
coenzyme: ________
PLP: pyridoxal phosphate
