Category: Biology Second Paper

(i) Glucose is a simple sugar.
(ii) It is a white granular substance.
(iii) It has a sweet taste.
(iv) It is soluble in water.
(v) It is slightly soluble in alcohol, but insoluble in ether.
(vi) It contains aldehyde group. Dr. Siddiq Publications
(vii) It is called aldose sugar.
(viii) It is a reactive sugar.
(ix) Glucose binds to proteins in the animal body to form glycoproteins.
(x) It reacts with phosphoric acid to form esters.
(xi) Its melting point is 146 degrees Celsius. (α- D glucose) and 150 degrees C. (β-D glucose).

Glucose is a six-carbon monosaccharide. It is a reducing sugar. Its molecular signal. It is called aldohexose as it contains aldehyde group. Ripe fruits and honey contain high amounts of glucose. As the ripe fruit contains 12-30% glucose, it is called grape sugar. It is called dextrose, corn sugar, grape sugar, blood sugar and D-glucose. Its relative sweetness is 74. Glucose is produced in the plant body in the process of photosynthesis. However, sugars are never stored in plant bodies. It acts as the primary component of respiration.

Glucose is a six-carbon monosaccharide. It is a reducing sugar. Its molecular signal. It is called aldohexose as it contains aldehyde group. Ripe fruits and honey contain high amounts of glucose. As the ripe fruit contains 12-30% glucose, it is called grape sugar. It is called dextrose, corn sugar, grape sugar, blood sugar and D-glucose. Its relative sweetness is 74. Glucose is produced in the plant body in the process of photosynthesis. However, sugars are never stored in plant bodies. It acts as the primary component of respiration.

Properties of Glucose
(i) Glucose is a simple sugar.
(ii) It is a white granular substance.
(iii) It has a sweet taste.
(iv) It is soluble in water.
(v) It is slightly soluble in alcohol, but insoluble in ether.
(vi) It contains aldehyde group. Dr. Siddique Publications
(vii) It is called aldose sugar.
(viii) It is a reactive sugar.
(ix) Glucose binds to proteins in the animal body to form glycoproteins.
(x) It reacts with phosphoric acid to form esters.
(xi) Its melting point is 146 degrees Celsius. (α- D glucose) and 150 degrees C. (β-D glucose).

Different types of glucose
(i) D Glucose (Dextrorotatory): If the hydroxyl (OH) group is attached to the right side of the 5th carbon of glucose.
It is called dextrorotatory or D glucose. Its rotation direction is to the right of the chiral center. It is a light activator. All natural glucose is D glucose. Dr. Siddique Publications
(ii) L Glucose (Laevorotatory): If the hydroxyl (OH) group is attached to the left side of the 5th carbon of glucose, it is called Laevorotatory or L glucose. Its rotation direction is to the left of the chiral center. It is a light activator. L-glucose is synthetically produced for use in diabetes medication and endoscopy. (The center along which the carbon molecules are linked is called the chiral center). Dr. Siddique Publications
(iii) α-D glucose and β-D glucose: Carbon 1 of glucose forms an oxygen bridge near carbon 5. A ring structure is formed as a result. An -OH group is generated due to the ring structure. If the -OH group is below the 1st carbon of glucose, it is called α-D glucose and if it is above the 1st carbon of glucose, it is called β-D glucose. α-glucose forms starch and β-glucose forms cellulose. D glucose is always present in the plant body.

Use of glucose
(i) Glucose is used as patient food. Quickly energizes the patient.
(ii) It is used in fruit preservation. Prevents fruit rot.
(iii) D-glucose is used to produce vitamin C from bacteria in the Richstein process.
(iv) Glucose is used in the preparation of calcium gluconate drugs.
(v) It plays a role in carbohydrate metabolism in the organism.
(vi) It is used to make citric acid, gluconic acid, bio-ethanol, sorbital etc.
(vii) It acts as a source of energy for sick people. Dr. Siddique Publications
(viii) Glycoproteins and glycolipids are formed from glucose.
(ix) Glucose is used in the process of glycolysis to generate energy.

Ribulose is a five-carbon monosaccharide. It is a reducing sugar. Its molecular symbol is C5H10O5. Since it contains a keto group, it is called a ketopentose sugar. Ribulose acts as a CO2 consumer in photosynthesis and produces ribulose 1, 5 bisphosphate. Ribulose 1, 5 bisphosphate is oxidized to form carboxyl compounds. Dr. Siddiq Publications

Ribose is a monosaccharide with five carbons. It is called D-ribose. Ribose was discovered by scientist Emil Fisher in 1891. Its molecular symbol is C5H10O5. Its melting point is 95 degrees Celsius. It is a reducing sugar. It is called aldopentose sugar as it contains aldehyde group. Capable of ribose oxidation. It reacts with Hcl to produce furfuric acid. Ribose acts as the building block of RNA. A purine or pyrimidine base combines with ribose to form a nucleoside. Nucleosides combine with inorganic phosphates to form nucleotides. Nucleotides are then combined to form RNA. Ribose helps in the formation of sugars in the photophosphorylation process. Ribose is attached to biomolecules like ATP, NAD+, NADP+, FAD, Co-A etc. Dr. Siddiq Publications

The muscular membrane between the thoracic and abdominal cavities of mammals

The word Eutheria is formed from the Greek word eu meaning nature and ther meaning mammal. Mammals that possess true immortality are called immortalized mammals or eutheria. They are spread throughout the world. Dr. Siddique Publications
(i) They are true immortal mammals. Their embryo consists of chorion and allantois.
(ii) Immortals provide nutrients during their flowering. The gestation period is long lasting.
(iii) Their embryos remain in the uterus for some time and give birth to mature neonates.
(iv) Mammary glands of female animals are highly developed. It contains nipples.
(v) Their vagina is one. The testes are located in the scrotal sac.
Example: Human (Homo sapiens), Shushuk (Platanista gangetica), mouse (Mus musculus), Rusa deer (Rusa unicolor), tiger (Panthera tigris), fruit bat (Pteropus giganteus).

The word Metatheria is formed from the Greek word meta meaning medium and ther meaning mammal. Mammals that have a pouch called a marsupium are called marsupials or metatheria. They live in Australia, Tasmania, New Guinea, Central and South America.
(i) They are simple immortal mammals.
(ii) They give birth to very immature neonates.
(iii) Female animals have pouch called marsupium. In this pouch the new-born attain fullness. Hence they are called marsupials.
(iv) Mammary glands including nipples are exposed in marsupium.
(v) They have two uteri and two vaginas.
Examples: Red kangaroo (Osphranter rufus/Macropus rufus), Virginia opossum (Didelphis virginiana), Koala (Phascolarctos cinereus).

The word Prototheria is formed from the Greek word protos meaning first and ther meaning mammal. Mammals that lay eggs are called ovipositors or prototheria. They live in Australia and New Guinea. Dr. Siddique Publications
(i) They are primitive egg-laying mammals. They are not immortal.
(ii) They lay eggs with a leathery covering. A newborn is born from an egg.
(iii) Newborns suck the mother’s milk. Because their mammary glands do not have nipples.
(iv) They have sharp lips, no teeth and no external ears.
(v) There is only one mucous membrane for excretory, reproductive and digestive system. Hence they are called monotrims.
Examples: Goose-billed Platypus (Ornithorhynchus anatinus), Short-billed Echidna (Tachyglossus aculeatus)

Class Mammalia is divided into three subclasses based on the nature of reproduction. These are Prototheria, Metatheria and Eutheria.
1. Prototheria: The word Prototheria is formed from the Greek word protos meaning first and ther meaning mammal. Mammals that lay eggs are called ovipositors or prototheria. They live in Australia and New Guinea. Dr. Siddique Publications
(i) They are primitive egg-laying mammals. They are not immortal.
(ii) They lay eggs with a leathery covering. A newborn is born from an egg.
(iii) Newborns suck the mother’s milk. Because their mammary glands do not have nipples.
(iv) They have sharp lips, no teeth and no external ears.
(v) There is only one mucous membrane for excretory, reproductive and digestive system. Hence they are called monotrims.
Examples: Goose-billed Platypus (Ornithorhynchus anatinus), Short-billed Echidna (Tachyglossus aculeatus)
2. Metatheria: The word Metatheria is formed from the Greek word meta meaning medium and ther meaning mammal. Mammals that have a pouch called a marsupium are called marsupials or metatheria. They live in Australia, Tasmania, New Guinea, Central and South America.
(i) They are simple immortal mammals.
(ii) They give birth to very immature neonates.
(iii) Female animals have pouch called marsupium. In this pouch the new-born attain fullness. Hence they are called marsupials.
(iv) Mammary glands including nipples are exposed in marsupium.
(v) They have two uteri and two vaginas.
Examples: Red kangaroo (Osphranter rufus/Macropus rufus), Virginia opossum (Didelphis virginiana), Koala (Phascolarctos cinereus).
3. Eutheria: The word Eutheria is formed from the Greek word eu meaning nature and ther meaning mammal. Mammals that possess true immortality are called immortalized mammals or eutheria. They are spread throughout the world. Dr. Siddique Publications
(i) They are true immortal mammals. Their embryo consists of chorion and allantois.
(ii) Immortals provide nutrients during their flowering. The gestation period is long lasting.
(iii) Their embryos remain in the uterus for some time and give birth to mature neonates.
(iv) Mammary glands of female animals are highly developed. It contains nipples.
(v) Their vagina is one. The testes are located in the scrotal sac.
Example: Human (Homo sapiens), Shushuk (Platanista gangetica), mouse (Mus musculus), Rusa deer (Rusa unicolor), tiger (Panthera tigris), fruit bat (Pteropus giganteus).