Metabolic pathways and ATP production I Flashcards Preview

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Flashcards in Metabolic pathways and ATP production I Deck (28)
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What are the net products of glycolysis?

2 ATP + 1 NADH


Which steps of glycolysis use and produce ATP?

Glucose --> G6P (-ATP)

Fructose-6-phosphate --> Fructose-1,6-bisphosphate (-ATP)

1,3-bisphosphoglycerate --> 3-phosphoglycerate (+ATP)

Phosphoenolpyruvate -->Pyruvate (+ATP)


What are the three fates of pyruvate?

Alcoholic fermentation Generation of lactate Generation of Acetyl-CoA


What does the pyruvate dehydrogenase complex consist of?

Lipoamide Reductase Transacetylase (Lipoamide)
Dihydrolipoyl Dehydrogenase (FAD)
Pyruvate Decarboxylase (Thiamine Pyrophosphate)
Other co-factors: NAD+ and CoA


what are the three stages of metabolism?

explain them

- digestion
enzymes breaking down larger molecules into smaller molecules

- cellular metabolism 1
oxidation of small molecules within the cytosol generating ATP and NADH

- cellular metabolism 2
Oxidation of small molecules generated in Cellular Metabolism 1 within mitochondria of cells. Generates ATP and waste products.


****show a cartoon of the three stages of cellular metabolism :



how is the large activation energy of glucose overcome?

- overcome by having several enzyme - catalysed reactions with small activation energies


how does glycolysis work?

- this is an anaerobic process where 6 carbon glucose is broken down into 2x3 carbon pyruvate
- it consists of 10 different reactions with 2 main concepts

- formation of high energy compound
(investing ATP)

- splitting of a high energy compound
(generating ATP)


define substrate level phosphorylation:

The production of ATP by the direct transfer of a high energy phosphate group from an intermediate substrate in a biochemical pathway to ADP, such as occurs in glycolysis.


what is oxidative phosphorylation?

The production of ATP using energy derived from the transfer of electrons in an electron transport system


what is lactate dehydrogenase a sign of?

o Stroke
o Heart Attack
o Liver Disease
o Muscle Injury
o Muscular
o Pulmonary


what is creatine phosphate?

creatine phosphate is a large reservoir of phosphate which can be used to phosphorylate ADP to ATP.


what does high levels of creatine phosphate show?

- muscle damage causes creatine phosphate to leak into blood stream

o Diagnose myocardial infarction
o Determine the extent of muscular disease
o Evaluate cause of chest pain
o Help discover carriers of muscular dystrophy


where does the generation of Acetyl CoA happen?

what happens to it?

- This occurs in the mitochondria

- The acetyl CoA formed enters the Krebs Cycle and ultimately produces ATP by oxidative phosphorylation in the electron transport chain


what does the pyruvate dehydrogenase complex consist of?

o 3 Enzymes
o 5 Co-factors


what enzymes are involved in Pyruvate Dehydrogenase?

1. Lipoamide reductase-transacetylase

2. Dihydrolipoyl dehydrogenase

3. Pyruvate decarboxylase


what cofactors are involved in pyruvate dehydrogenase?

1. Thiamine pyrophosphate (TPP)
2. Lipoamide
3. FAD
4. CoA
5. NAD+


what is TPP?

- Derivative of Vitamin B

- Readily loses proton and resulting carbanion attacks that of pyruvate to produce hydroxyethyl-TPP.

- Deficiency of Vitamin B1 causes Beri-Beri


symtoms of beri beri?

damage to peripheral nervous system, weakness of musculature and decreased cardiac output.


what is lipoamide?

- Functional group undergoes oxidation and reduction
- Long arm allows dithiol group to swing from one active site to another


what can inhibit
pyruvate dehydrogenase?

Arsenite and mercury


what does FAD do?

FAD accepts and donates 2 electrons + 2 protons


how much ATP does anaerobic respiration make?



how much ATP does aerobic respiration make?

38 ATP


explain alcoholic fermentation?

pyruvate ------> acetaldehyde
using pyruvate decarboxylase

acetaldehyde ------> ethanol
using alcohol dehydrogenase

also makes Co2 and Nad+


explain the generation of lactate?

Pyruvate ------> lactate

uses lactate dehydrogenase

also makes NAD+


explain the generation of acetyl CoA?

creatine phosphate ------> creatine + ATP

uses creatine phosphate pyruvate dehydrogenase complex

also makes NADH and CO2


why is NAD+ essential?

The dehydrogenation of glyceraldehyde-3-phopshate needs NAD+,

so glycolysis keeps happening