PBIO FINALS - Metabolic Pathways of Biomolecules Pt. 4

white blood cell

produce a significant amount of superoxide free radicals via the following reaction to destroy the invading bacteria and viruses

>95%

ROS formed are quickly converted to nontoxic species in the ff rxns.

5%

ROS escape destruction by superoxide dismutase and catalase enzymes

1. Vit. K

2. Vit. C

3. Glutathione

4. Beta-carotine

Antioxidant molecules present in the body help trap ROS species.

flavonoids

are also good antioxidants and have shown promise in the management of many disorders associated with ROS production

Glycerol-3-phosphate-dihydroxyacetone phosphate

transport system shuttles electrons from NADH, but not NADH itself, across the membrane

1. Dihydroxyacetone phosphate

2. Glycerol phosphate

freely cross the mitochondrial membrane

30 ATP

number of molecules are produced in muscle and nerve cells

26

from oxidative phosphorylation of ETC

2

from oxidation of glucose to pyruvate

2

from conversion of GTP to ATP

aerobic oxidation

15x more efficient in the ATP production as compared to anaerobic lactate and ethanol processes

glycogen

branched polymer form of glucose that serves as the storage form of carbohydrates

glycogen in muscles

source of glucose for glycolysis

glycogen in liver tissues

source of glucose to maintain normal blood sugar levels

glycogenesis

metabolic pathway by which glycogen is synthesized from glucose

Formation of glucose-1-phosphate

Glycogenesis Step 1

Formation of UDP-Glucose

Glycogenesis Step 2

Glucose transfer to a glycogen chain

Glycogenesis Step 3

degradation of glycogen

several glucose residues can be released simultaneously, one from each end of a branch, rather than one at a time as would be the case in a linear polymer

glycogenolysis

In the degradation of glycogen, several glucose residues can be released simultaneously, one from each end of a branch, rather than one at a time as would be the case in a linear polymer.

Formation of Glucose-1-phosphate

Glycogenolysis Step 1

Isomerization of glucose-1-phosphate to glucose-6-phosphate

Glycogenolysis Step 2

glycolysis pathway

The locally produced glucose 6-phosphate directly enters the _____.

Low glucose levels

______ stimulates glycogenolysis in liver cells

glucose

Enzyme glucose 6-phosphatase found in liver, kidneys, and intestine convert glucose 6-phosphate to ____.

blood

The free glucose is then transported to muscle and brain via ______.

gluconeogenesis

Metabolic pathway by which glucose is synthesized from non-carbohydrate sources.

12-18 hours

Glycogen stores in muscle and liver tissues are depleted within ____ from fasting or from heavy or strenuous physical activity.

gluconeogenesis

Without _____, the brain, w/c is dependent on glucose as a fuel, would have problems functioning if food intake were restricted for even one day.

Gluconeogenesis

helps to maintain normal blood glucose levels in times of inadequate dietary carbohydrate intake

Glycogenesis

- 2-step process

- (Glu 6-PO4 to Glycogen)

Gluconeogenesis

- 11-step process

- (Pyruvate to Glucose)

Glycolysis

- 10-step process

- (Glu to Pyruvate)

glycogenolysis

(Glycogen to Glu 6-PO4)

pentose phosphate pathway

alternative to glycolysis

pentose phosphate pathway

Involves oxidation reactions that produce NADPH and five-carbon sugars.