BIOCHEM PART 2 - METABOLISM OF CARBOHYDRATES

one sugar unit

one sugar unit

Monosaccharides has ____ sugar unit

two sugar units

Disaccharides has ____ sugar unit

3-10 sugar units

Oligosaccharides has ____ sugar unit

more than 10 sugar units

polysaccharides has ____ sugar unit

Mouth

Polysaccharides → oligosaccharides are broken down in ___

Salivary Amylase

This enzyme helps in breaking down Polysaccharides → Oligosaccharides

Small Intestines

Oligosaccharides → Disaccharides and Monosaccharides are broken down in

Pancreatic Amylase

This enzyme helps in breaking down Oligosaccharides → Disaccharides and Monosaccharides

Hydrolytic Enzymes

1. Maltase

2. Sucrase

3. Lactose

This enzyme helps in breaking down Disaccharides —> Monosaccharides

2 glucose

Maltose is formed from __

1 glucose and 1 fructose

Sucrose is formed from __

1 glucose and 1 galactose

Lactase is formed from __

Monosaccharides

They are absorbed by simple passive diffusion into the portal blood system for METABOLISM or STORAGE as glycogen in the liver

Glucose

Major form of carbohydrate that enters the cell after absorption from the gut

Glucose

It is the major fuel used by the BRAIN cells

Glucose Transporters

transmembrane proteins that specifically bind glucose and transports it inside the cell from the blood

GLUT 1,3

• Found in almost all cell types (specifically brain cell)

• Transport glucose even if the level is LOW

GLUT 2

• Liver and pancreatic cells

• Works only when glucose level is HIGH

HINT: DUA LIPA

GLUT 4

Muscle and adipose tissues

HINT: I AM #4

GLUT 5

Glucose transporter that is found in Fructose

GLUT 7

Glucose transporter that is found in Fructose and Glucose

Glycolysis

Embden Meyerh of Parnas Pathway is also known as __

Oxygen

Anaerobic (no direct use of__________)

Break down of Glucose

Glycolysis means what?

Hexokinase

An enzyme that helps to catalyze:

glucose → glucose-6- phosphate

Phosphoryl Group Transfer

glucose → glucose-6- phosphate is what type of reaction?

Phosphoglucoisomerase or Glucose-6-isomerase

An enzyme that helps to catalyze:

glucose-6-phosphate —> fructose-6-phosphate

Isomerization

glucose-6-phosphate —> fructose-6-phosphate is what type of reaction?

Phosphofructokinase

An enzyme that helps to catalyze:

fructose-6-phosphate —> fructose-1,6- biphosphate

Phosphoryl Group Transfer

fructose-6-phosphate —> fructose-1,6- biphosphate is what type of reaction?

Aldolase

An enzyme that helps to catalyze:

fructose-1,6- biphosphate —> glyceraldehyde 3-phosphate & dihydroxyacetone phosphate

Aldol Cleavage

fructose-1,6- biphosphate —> glyceraldehyde 3-phosphate & dihydroxyacetone phosphate is what type of reaction?

TRUE

TRUE OR FALSE

dihydroxyacetone phosphate can’t be oxidized, so they are also metabolized to glyceraldehyde 3-phosphate

Triose Phosphate Isomerase

An enzyme that helps to catalyze dihydroxyacetone phosphate —>glyceraldehyde 3-phosphate

Isomerization

dihydroxyacetone phosphate —>glyceraldehyde 3-phosphate is what type of reaction?

glyceraldehyde 3-phosphate Dehydrogenase

An enzyme that helps to catalyze:

glyceraldehyde 3-phosphate —> 1,3 biphosphoglycerate

Oxidation Reduction Phosphorylation

glyceraldehyde 3-phosphate —> 1,3 biphosphoglycerate is what type of reaction?

phosphoglycerate kinase

An enzyme that helps to catalyze:

1,3 bisphosphoglycerate —> 3-phosphoglycerate

Phosphoryl Group Transfer

1,3 bisphosphoglycerate —> 3-phosphoglycerate is what type of reaction?

phosphoglycerate mutase

An enzyme that helps to catalyze:

3-phosphoglycerate —> 2 phosphoglycerate

Phosphoryl group shift

3-phosphoglycerate —> 2 phosphoglycerate is what type of reaction?

Enolase

An enzyme that helps to catalyze:

2-phosphoglycerate —> phosphoenolpyruvate

Dehydration

2 phosphoglycerate —> phosphoenolpyruvate is what type of reaction?

Pyruvate Kinase

An enzyme that helps to catalyze: phosphoenolpyruvate —>pyruvate

Phosphoryl Group Transfer

phosphoenolpyruvate —>pyruvate is what type of reaction?

Energy Investment

Step 1-5 of Glycolysis is known as

Pay Off

Step 6-10 of Glycolysis is known as

• 2 Pyruvate

• 2 ATPs

• 2 NADH

Products of Glycolysis

Rate Limiting Enzymes

This controls and limit the rate of glycolysis

Steps 1, 3, 10

• Hexokinase

• PFK

• Pyruvate Kinase

In which stages of Glycolysis do Rate Limiting Enzymes occur?

Phosphofructokinase 1

Activated by: AMP and fructose-1,6-bisphosphate

Inhibited by: ATP

Hexokinase

Activated by: Glucose

Inhibited by: Glucose-6-Phosphate

Pyruvate Kinase

Activated by: PEP

Inhibited by: ATP and alanine

GLUCONEOGENESIS

Formation of glucose from non-sugar (non-carbohydrate) precursors, which during conditions of starvation, it becomes the major source of glucose for muscle and brain cells

• Glycerol

• Amino acids

• Lactic acid

what are the non-sugar (non-carbohydrate) precursors?

Liver

Gluconeogenesis occurs mostly in the ________

Alanine Transferase

An enzyme that helps to catalyze

Alanine (and other amino acids) -> pyruvate

Pyruvate Carboxylase

An enzyme that helps to catalyze:

Pyruvate + CO2 —> Oxaloacetate

Malate dehydrogenase

An enzyme that helps to catalyze:

Oxaloacetate (mitochondria) —> Malate (mitochondria)

Malate dehydrogenase

An enzyme that helps to catalyze

Malate (cytosol) —> Oxaloacetate (cytosol)

PEP Carboxykinase

An enzyme that helps to catalyze:

Oxaloacetate → PEP (Phosphoenolpyruvate)

Fructose-1,6- biphosphaTASE

An enzyme that helps to catalyze:

Fructose 1,6-bisphosphate→ Fructose-6-phosphate

Glucose-6- phosphaTASE

An enzyme that helps to catalyze:

Glucose-6-phosphate —> Glucose