Carbohydrates Metabolic Pathways: Generation of Energy Flashcards by KYNA MAE MERILLES

breakdown of glucose into 2 pyruvate
molecules to form ATP (Embden Meyerhoff Pathway)

Glycolysis

How well did you know this?

Not at all

Perfectly

conversion of non-glucose hexoses (like mannose, fructose and galactose), lipids, amino acids to form more ATPs

Gluconeogenesis

How well did you know this?

Not at all

Perfectly

synthesis of glycogen (stored in the liver and muscles) from excess glucose. (INSULIN)

Glycogenesis

How well did you know this?

Not at all

Perfectly

Glycogenesis is stimulated by what hormone

INSULIN

How well did you know this?

Not at all

Perfectly

breakdown of glycogen to glucose for ATP production

Glycogenolysis

How well did you know this?

Not at all

Perfectly

Gluconeogenesis:
____ + a-ketoglutarate —>____ + glutamate

Alanine; pyruvate

How well did you know this?

Not at all

Perfectly

Gluconeogenesis:
____ + a-ketoglutarate —> ____ + glutamate

Aspartate; oxaloacetate

How well did you know this?

Not at all

Perfectly

Most human tissues cannot utilize ____ and ____

galactose & fructose

How well did you know this?

Not at all

Perfectly

The both phosphorylates fructose to fructose-6-
PO4

Fructokinase & hexokinase

How well did you know this?

Not at all

Perfectly

has a much higher affinity for glucose than fructose

hexokinase

How well did you know this?

Not at all

Perfectly

utilizes fructose-1,6 biphosphate as substrate

Aldolase

How well did you know this?

Not at all

Perfectly

It lacks of fructokinase

Fructosuria

How well did you know this?

Not at all

Perfectly

Is benign and asymptomatic

Fructosuria

How well did you know this?

Not at all

Perfectly

It may be misinterpreted as glucosuria, (positive reducing sugar test)

Fructosuria

How well did you know this?

Not at all

Perfectly

It lacks of aldolase (F-1,6
biPO4 cleavage)

Fructose Intolerance

How well did you know this?

Not at all

Perfectly

In Fructose Intolerance what happens upon sucrose or fructose intake

Hypoglycemia & vomiting

How well did you know this?

Not at all

Perfectly

is obtained from milk sugar.

galactose

How well did you know this?

Not at all

Perfectly

The most important organs that can metabolize galactose

liver and erythrocytes

How well did you know this?

Not at all

Perfectly

The 2 enzyme defects resulting to galactosemia

Lack of galactokinase
Lack of galactose-1-phosphate uridyl transferase

How well did you know this?

Not at all

Perfectly

the synthesis of glycogen from monosaccharides

GLYCOGENESIS

How well did you know this?

Not at all

Perfectly

Main storage for glycogen

Liver, muscle cells

How well did you know this?

Not at all

Perfectly

Glycogen storage in normal tissues

300-320 grams/day

How well did you know this?

Not at all

Perfectly

Group of inherited metabolic disorders that involve the lack of or abnormality of enzymes regulating glycogen catabolism and anabolism

Glycogen Storage Diseases

How well did you know this?

Not at all

Perfectly

Glycogen Storage Diseases Abnormality in _____ and ____

glycogenesis & glycogenolysis

How well did you know this?

Not at all

Perfectly

Accumulation of abnormal glycogen by-products can damage

liver, muscles, heart and other organs

Enzyme Deficiency in VON GIERKE’S

Glucose-6-phosphatase

Enzyme Deficiency in POMPE’S

Alpha-1,4-glucosidase

Enzyme Deficiency in CORI’S

Amylo-1,6-glucosidas

Enzyme Deficiency in ANDERSEN’S

Alpha-1,4-glucan, 6-glucosyl- transferase

Enzyme Deficiency in McARDLE’S

Muscle phosphorylase

Enzyme Deficiency in HER’S

Hepatic phosphorylase

Enzyme Deficiency in TARUI’S

Muscle phosphofructokinase

Enzyme Deficiency in VIII

Adenyl kinase

Enzyme Deficiency in IX

Hepatic phosphorylase b kinase

Enzyme Deficiency in X

Cyclic AMP-dependent kinase

severe hepatomegaly, and hypoglycemia, lactic acidosis, hyperlipidemia, failure to thrive

VON GIERKE’S

Infant-cardiomegaly, muscle, early death Adult-muscle weakness

POMPE’S

Hepatomegaly, muscle weakness and hypoglycemia

CORI’S

Hepatomegaly, cirrhosis, failure to thrive, early death

ANDERSEN’S

Muscle cramps after exercise, myoglobinuria in some patients

McARDLE’S

Hepatomegaly, mild clinical course

HER’S

Muscle cramps after exercise, myoglobinuria in some patients

TARUI’S

HORMONES THAT REGULATE BLOOD SUGAR LEVEL

Insulin, Glucagon, Somatostatin, Growth hormone, Thyroxine, Cortisol and Corticosteroids, Epinephrine and Norepinephrine, ACTH: (anterior pituitary), Somatomedins

It enhances entry of glucose into the liver, muscle and adipose tissues.

Insulin

Glucagon

Ø promotes hepatic glycogenolysis and gluconeogenesis Ø ↑ Blood glucose

Ø inhibits secretion of insulin and glucagon Ø inhibits the release of GH Ø ↑ Blood glucose

Somatostatin

Ø antagonist to insulin; Ø it stimulates lipolysis (gluconeogenesis) Ø ↑ Blood glucose

Growth hormone

Ø Stimulates glycogenolysis and the rate of gastric emptying and intestinal absorption of glucose Ø ↑ Blood glucose

Thyroxine/Tetraiodothyronine

Ø Stimulates gluconeogenesis Ø ↑ Blood glucose

Cortisol and Corticosteroids

Ø ↑ Blood glucose Ø gestational diabetes

Human Placental Lactogen (hPL)

Øpromotes both liver and skeletal glycogenolysis

Epinephrine and Norepinephrine

Øphysical or emotional stress cause increase production of epinephrine and an immediate production of glucose for energy Ø↑ Blood glucose

Epinephrine and Norepinephrine

glucose breakdown to form pyruvate and with the release of ATP molecules as the source of biochemical energy.

Glycolysis: aka- Embden Meyerhoff Pathway

Alternative pathway where glucose molecules can also be catabolized and form ATP molecules.

Pentose Phosphate Pathway/ Hexose Monophosphate Shunt/Phosphogluconate Oxidative Pathway

It is the final common pathway for the breakdown of foodstuff where acetyl coA is utilized to generate this cycle in repoducing ATP.

Kreb’s Cycle/Citric Acid cycle/Tricarboxylic Acid cycle

ØHydrolysis of glucose; major pathway for the utilization of glucose

GLYCOLYSIS

Importance of glycolysis

Production of Adenosine triphosphate (ATP)

FATE OF PYRUVATE in Glycogenesis

converted to glucose-6-PO4

FATE OF PYRUVATE in Gluconeogenesis

ammonia —> alanine

FATE OF PYRUVATE in Citric acid Cycle

Oxidative decarboxylation and combine with CoA —> acetyl CoA

FATE OF PYRUVATE in Fermentation

Lactic acid

oThe RBCs contain low concentration of the glycolytic intermediates, including the precursor, 2,3- Diphosphoglycerate (2,3-DPG)

HEXOKINASE DEFICIENCY

oAll RBCs are completely dependent upon glycolytic activity for ATP production oFailure of the pyruvate kinase reaction drastically impedes the production of ATP

PYRUVATE KINASE DEFICIENCY (Hemolytic Anemia)

the values for blood lactate may be ≥5.0 mM

LACTIC ACIDOSIS

common cause of hyperlactidemia

ANOXIA

The shortage of O2 reduces mitochondrial production of ATP with the consequent activation of PFK, causing increased glycolysis and lactate production

ANOXIA

Øprocess where the pyruvate produced in glycolysis undergoes further breakdown. Ørequires oxygen and yields much more energy than glycolysis.

AEROBIC RESPIRATION

Two processes in AEROBIC RESPIRATION

Krebs cycle Electron Transport Chain and Oxidative Phosphorylation

Final common pathway of oxidative catabolism of all fuel molecules in aerobic cells (mitochondrial matrix)

TRICARBOXYLIC ACID CYCLE/CAC/KREB’S CYCLE

Glycolysis is also known as

Embden Meyerhoff Pathway

Regulator for Glycogenesis

Insulin

Regulator for Glycogenolysis

Glucagon

Secretes Growth/ somatotrophic hormone

Anterior pituitary gland

Secrets glucagon hormone

Alpha cells

Secretes insulin

B-cells/ beta cells

Secrets Somatostatin

Delta cells

Secretes Thyroxine

Thyroid gland

Secretes Cortisol and Corticosteroids

Adrenal cortex = chromaffin cells

Secretes Adrenocorticotropic hormone

Anterior pituitary

Secretes epinephrine and norepinephrine

Adrenal medulla = chromaffin cells

Secretes somatomedins

Liver