B1.1 - Carbohydrate and lipids - IB Bio

Question 1

State the nature of a covalent bond

Answer 1

A covalent bond is a type of chemical bond that involves the sharing of electrons between two atoms. In a covalent bond, the atoms are held together because they share one or more pairs of electrons, with each atom contributing electrons to the shared pair(s). This sharing of electrons allows both atoms to achieve a more stable electron configuration, usually resembling the noble gas configuration, by filling their outermost electron shells. Covalent bonds typically occur between nonmetals or between nonmetals and hydrogen in molecules and compounds.

Question 2

How many bonds can a carbon atom have?

Answer 2

A carbon atom can have up to 4 single bonds or a combination of single and double bonds with other carbon atoms or atoms of non-metallic elements.

Question 3

State two examples of each molecule that’s branched and unbranched

Answer 3

Unbranched Alkane: Ethane (C2H6)Unbranched Amino Acid: Glycine (C2H5NO2)Branched Alkane: IsobutaneBranched Amino Acid: Valine

Question 4

State two examples of each molecule that’s single and multiple rings

Answer 4

Single ring: - Benzene (C6H6)- Cyclohexane (C6H12)Double ring: - Naphthalene (C10H8)- Biphenyl (C12H10)

Question 5

What does organic mean?

Answer 5

This refers to a molecule containing Carbon and Hydrogen such as methane and glucose. Carbon-Hydrogen bond

Question 6

What does inorganic mean?

Answer 6

This refers to a molecule not containing Carbon and hydrogen such as carbon dioxide and water.No Carbon-Hydrogen bond

Question 7

What type of bond does a carbon atom form?

Answer 7

Carbon atoms can form 4 stable non-polar covalent bonds with other atoms. These 4 covalent bonds allow the molecules to branch off in 4 different directions and make large and complex molecules. Carbon atoms readily bond with each other producing chains or rings of carbon atoms. Carbon chains form the backbones of most organic molecules, which can vary in length, branching, placement of double bonds, and location of atoms of other elements.

Question 8

State the functional groups that Carbon can combine with

Answer 8

• Hydroxl group - OH (common in alcohols)- Carboxyl group - COOH (found in fatty acids and amino acids)- Amine group - NH2 (found in amino acids)- Phosphate group - PO2-4 (found in ATP and ADP which are used to transfer energy between molecules)

Question 9

What is a polymer?

Answer 9

Polymers are chains of subunits (monomors)

Question 10

How are monomers joined to form a polymer?

Answer 10

Monomers are joined together to form a polymer through condensation. This involves the production of water and also involves the use of ATP.

Question 11

When does a condensation reaction occur?

Answer 11

Condensation reaction occurs when molecules are covalently joined together and water is formed as a by-product. In carbohydrates, the bond that is formed is called a glycosidic linkage.

Question 12

What is a monosaccharide?

Answer 12

A monosaccharide is the simplest form of a carbohydrate, often referred to as a single sugar molecule. Monosaccharides are organic compounds composed of carbon (C), hydrogen (H), and oxygen (O) atoms in a specific ratio. Monosaccharides have a basic, unbranched structure consisting of a single sugar molecule. They cannot be hydrolyzed (broken down) further into simpler sugars.Some examples of monosaccharides are glucose, fructose, galactose, ribose and dioxyribose.

Question 13

What is a disaccharide?

Answer 13

A disaccharide is a type of carbohydrate composed of two monosaccharide (simple sugar) molecules linked together through a covalent bond known as a glycosidic bond. When two monosaccharides combine through a condensation reaction, where a molecule of water is removed, they form a disaccharide. Disaccharides are a class of sugars and are a common component of many foods.Some examples of disaccharides are sucrose and lactose.

Question 14

What is a polysaccharide?

Answer 14

A polysaccharide is a type of carbohydrate, often referred to as a complex carbohydrate, composed of multiple monosaccharide (simple sugar) molecules linked together through glycosidic bonds. Polysaccharides are large, long-chain molecules that serve various important functions in living organisms, including energy storage. Some examples of polysaccharides are starch, glycogen, and cellulose.

Question 15

What is a macromolecule?

Answer 15

macromolecule is a large, complex molecule typically composed of repeating subunits called monomers. These molecules are often essential to biological processes and can be found in living organisms. Macromolecules are classified into four main categories: proteins, carbohydrates, lipids and nucleic acids. For example, Nucleic acids, such as DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are macromolecules made up of nucleotide monomers. They store and transmit genetic information, allowing for the inheritance of traits and the synthesis of proteins.

Question 16

What is a polymer?

Answer 16

A polymer is a large molecule composed of repeating subunits called monomers. These monomers are covalently bonded together in a chain-like fashion, forming a long and often complex macromolecule. Polymers can vary in size, structure, and properties, depending on the type of monomers and the way they are linked.The process of forming a polymer from monomers is called polymerization. There are two primary types of polymerization: Addition and condensation.

Question 17

Explain the condensation reaction

Answer 17

A condensation reaction, also known as a dehydration synthesis reaction, is a chemical process in which two molecules combine to form a larger molecule, accompanied by the elimination of a smaller molecule, often water. In condensation reactions, functional groups within the molecules interact, resulting in the formation of new covalent bonds and the release of a byproduct, typically water or another simple molecule.ELIMINATION OF WATER

Question 18

Explain a hydrolysis reaction

Answer 18

Hydrolysis is the opposite of condensation. This reaction requires a water molecule to break a covalent bond between two subunits. ADDITION OF WATER

Question 19

The chemical formula of glucose

Answer 19

C6H12O6

Question 20

Physical properties of glucose

Answer 20

It’s soluble and a relatively small molecule, so it can be easily transported into the blood. It can also circulate in the blood and it’s dissolved in the plasma. Chemically stable molecule which makes it useful for food storage. If there are large quantities of glucose in a cell it can cause water to move into the cell through osmosis. This is why glucose if often converted into starch for plants and glycogen for animals. In this form, it doesn’t affect the osmotic potential of the cell.