Chapter 27: Specific Catabolic Pathways

Flashcards covering carbohydrate, lipid, and protein metabolism

What are the products of carbohydrate catabolism?

Monosaccharides

What are lipids hydrolyzed into?

Glycerol and fatty acids

What are products of protein hydrolysis?

Amino acids

What comprises the common pathway in the convergence of catabolic pathways?

Citric acid cycle and oxidative phosphorylation

Where does glycolysis occur?

Cytosol of all cells

Is glycolysis aerobic or anaerobic?

Can function either aerobically or anaerobically

What is the net conversion during glycolysis?

2 ADP to 2 ATP

What is the end product of glycolysis?

Two molecules of pyruvate

How many ATP are used to split glucose?

2 ATP

How many ATP and NADH are produced during the oxidation of 2 glyceraldehyde-3-phosphate to 2 pyruvate?

4 ATP and 2 NADH

What are the products of glycolysis?

2 Pyruvate, 2 NADH, 2 ATP, 2H2O, and 2H+

What yields are produced in the net of glyocolysis?

2 ATP and 2 NADH per glucose

What enzyme catalyzes the first step of glycolysis?

Hexokinase

What does cleavage of Fructose 1,6-bisphosphate yield?

An aldose and a ketose

What is the product when Dihydroxyacetone phosphate is reversibly converted to?

Glyceraldehyde 3-phosphate

Which substrate is used in the last step of glycolysis?

Phosphoenolpyruvate

What happens to pyruvate under anaerobic conditions?

It converts to Lactate

What happens to pyruvate under aerobic conditions?

It converts to acetly CoA

What is the most important pathway for the regeneration of NAD+ in vertebrates under anaerobic conditions?

Reduction of pyruvate to lactate

How do yeast regenerate NAD+?

Decarboxylation of pyruvate to acetaldehyde, followed by reduction to ethanol

What happens to pyruvate under aerobic conditions?

Undergoes oxidative decarboxylation to form acetyl CoA

What is the role of hexokinase, phosphohexose isomerase, phosphofructokinase, aldolasem and phosphotriose isomerase?

Spliting glucose to form 2 glyceraldehyde-3-phosphate

What do Phosphoglycerate kinase, Phosphoglycerate mutase Enolas e Pyurvate kinase Dihydrogenase do?

Oxidize to 2 pyruvate producing 4 ATP and 2 NADH

What is the main function of pentose phosphate pathway?

To produce NADPH ,H+ and pentoses for the synthesis of nucleotides.

What is the destination of Glyceraldehyde 3-phosphate?

Enters glycolysis after step 5

What is ketogenesis?

synthesis of ketone bodies from acetyl CoA which is derived mainly from B-oxidation of fatty acids

Where does ketogenesis take place?

Mitochondria in the liver cells

Where does Ketolysis Occur?

Extrahepatic tissues ( Non-Liver tissue)

What is the product of transamination?

New amino acid and new ketoacid

What happens to excess amino acids?

They are degraded via: Removal of α-amino group Ammonia (NH3) Remaining carbon skeleton Energy metabolism

Where does nitrogen catabolism in the liver occur?

Transamination, Oxidative Deamination, and the Urea Cycle

Where location of the Urea cycle in the body?

Liver cells

What acid are Amino acids whose carbon skeletons are degraded to?

Pyruvate or oxaloacetate

What acid are Amino acids whose carbon skeletons are degraded to?

acetyl CoA or acetoacetyl CoA

What happens when red blood cells are destroyed?

Globin is hydrolyzed to amino acids to be reused. Iron is preserved in ferritin and reused and Heme is converted to bilirubin.

What is β-Oxidation?

A series of five enzyme-catalyzed reactions that cleaves carbon atoms two at a time from the carboxyl end of a fatty acid