Carbohydrate Metabolism Flashcards
Organic molecules made up of carbon, hydrogen and oxygen atoms are called?
Carbohydrates
The two major types of carbohydrates include both?
Simple sugars
Complex sugars
Simple sugars are made up of?
Glucose and fructose etc
Complex sugars are made up of?
Starch
Glycogen
Cellulose
The classification of carbohydrates are?
Monosaccharides
Disaccharides
Oligosaccharides
Polysaccharides
Complex sugars are also called?
Polysaccharides
Polysaccharides are made up of multiple?
Monosaccharides
The two major functions of polysaccharides are?
Serve as energy storage (starch and glycogen)
Serve as structural components (chitin & cellulose)
Salivary amylase digests polysaccharides into?
Smaller oligosaccharides
Maltose is broken down into__1__ & __2__ by __3__
- Glucose
- Glucose
- Maltase
Lactose is broken down into__1__ & __2__ by __3__
- Galactose
- Glucose
- Lactase
Sucrose is broken down into__1__ & __2__ by __3__
- Fructose
- Glucose
- Sucrase
Amylase is denatured in the stomach by?
HCl
The dietary carbohydrates are the?
Monosaccharides
The dietary carbohydrates are the?
Monosaccharides
Disaccharides
Polysaccharides
Three examples of Monosaccharides are?
Glucose
Fructose
Galactose
The process by which cells break down fuel molecules through different metabolic pathways to transfer their energy into high energy compounds is called?
Cellular respiration
Examples of high energy compounds are?
ATP GTP NADH FADH2 NADPH
ATP means?
Adenosine-5-triphosphate
GTP means?
Guanosine-5-triphosphate
NADH means?
Reduced nicotinamide adenine dinucleotide
FADH2 means?
Reduced flavin adenine dinucleotide
NADPH means?
Reduced nicotinamide adenine dinucleotide phosphate
Why is glucose the body’s most readily available source of energy?
It is relatively rich in potential energy(energy stored in chemical bonds)
It supplies a huge array of metabolic intermediates for biosynthetic reactions
It can be used to produce ATP aerobically or anaerobically from its intercellular storage polymers
Glucose has three major pathways of utilisation, namely?
Glucose to pyruvate(oxidation via glycolysis)
Glucose to ribose-5-phosphate & NADH(oxidation via PPP)
Glucose to polysaccharides
What stores excess glucose as glycogen in the liver?
Hepatocytes
In glycolysis, a molecule of glucose is converted into?
Two molecules of pyruvate
In glycolysis, some of the free energy released from glucose is conserved in the form of?
ATP
NADH
The two phases of glycolysis are?
Preparatory phase
Pay-off phase
In the preparatory phase of glycolysis, how many molecules of ATP are used?
2
In the pay-off phase of glycolysis, how many molecules of ATP are produced?
4
The net yield of glycolysis is?
2 ATP
2 NADH
Examples of Phosphorylated derivatives of hexose sugars are?
D-fructose
D-mannose
D-galactose
Hexoses can enter into the glycolytic pathway by being converted into?
A Phosphorylated derivative
D-fructose is present in its free from in?
Fruits
D-fructose is formed from the ____ in the small intestine
Hydrolysis of sucrose
D-fructose is phosphorylated by__1__ to give__2__
- Hexokinase
2. fructose-6-phosphate
The metabolism of D-fructose occurs in the?
Muscle
Kidney
Liver
In the liver, fructose is phosphorylated by __1__ to give __2__
- Fructokinase
2. Fructose-1-phosphate
Fructose -1-phosphate is converted into __1__ & __2__ by Fructose -1-phosphate aldolase
- Glyceraldehyde
2. Dihydroxyacetone phosphate
Phosphorylated derivatives are also called?
Intermediates of the glycolytic pathway
Dihydroxyacetone phosphate is converted into __1__ by the glycolytic enzyme __2__
- Glyceraldehyde-3-phosphate
2. Triose phosphate isomerase
Glyceraldehyde is converted into glyceraldehyde-3-phosphate by?
ATP & triose kinase
Fructoses enter the glycolytic pathway at step ___ of glycolysis
5
Fructoses enter the glycolytic pathway as?
Fructose-6-phosphate and glyceraldehyde-3-phosphate
D-mannose can be found in?
Glycoproteins of food
Various polysaccharides
D-mannose is phosphorylated by __1__ to give __2__
- Hexokinase
2. Mannose-6-phosphate
Mannose-6-phosphate is isomerized by ___ to give fructose-6-phosphate
Phosphomannose isomerase
Mannose enters the glycolytic pathway at step __ of glycolysis
3
Mannose enters glycolysis as?
Fructose-6-phospate
Galactose is converted into glucose in the ____ pathway
Leloir
Galactose is converted into galactose -1-phosphate by?
Galactokinase
UDP galactose is converted into UDP glucose by?
UDP glucose epimerase
galactose -1-phosphate is converted into UDP galactose by?
Galactose-1-phosphate uridyltransferase
3 problems of galactose metabolism are?
Galactose-1-phosphate uridyltransferase deficiency
Galactokinase deficiency
Uridine diphosphate-galactose-4-epimerase deficiency
The inability of the body to use galactose to produce energy is called?
Galactosemia
Galactosemia is a rare disease in?
Infants
Classical Galactosemia is caused by the deficiency of?
Galactose-1-phosphate uridyltransferase
Galactosemia is inherited as ?
Autosomal recessive disorder
Mutation in the ___ on chromosome 9 is responsible for galactosemia
GALT gene
Increased galactose levels in the urine is called?
Galactosuria
Accumulated galactose is diverted for the production of___ by the enzyme aldol reductase
Galactitol
Galactitol has been implicated in the development of?
Cataract
Galactitol and galactose-1-phosphate accumulation in body tissues leads to ___ in their functions
Impairment
Four clinical symptoms of galactosemia are?
Jaundice
Mental retardation
Weight loss(infants)
Cataract (severe cases)
The diagnosis of galactosemia is done by measuring galactose-1-phosphate uridyltransferase activity in the?
Erythrocytes
The treatment of galactosemia is carried out by?
Supplying diet lacking in galactose and lactose
Galactokinase deficiency or GALK is caused by?
Mutation of GALK1 gene
GALK symptom is?
Cataract
GALK is treated by?
Eating food lacking galactose and lactose
Uridine diphosphate galactose-4-epimerase deficiency (GALE) symptoms are?
Cataracts
Liver disease
Kidney problems
GALE is caused by?
Mutation in GALE gene
Non- classical galactosemia is caused by?
Deficiency of UDP galactose-4-epimerase