Chemical Nature Of Cells

Question 1

What is metabolism?

Answer 1

Metabolism refers to all of the chemical reactions that take place inside of organisms to allow life to occur.

Question 2

What is an atom?

Answer 2

An atom is the smallest particle of a chemical element that can exist.

Question 3

What does water consist of?

Answer 3

Each water molecule consists of a combination of a single oxygen atom with two hydrogen atoms.

Question 4

What is a covalent bond?

Answer 4

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.

Question 5

Define hydrophilic

Answer 5

Having a tendency to mix with, dissolve in, or be wetted by water.

Question 6

Define hydrophobic

Answer 6

Hydrophobic refers to tending to repel or fail to mix with water.

Question 7

What is pH?

Answer 7

pH is a scale that provides a measure of hydrogen ions in a solution and hence the state of the acidity or alkalinity of a solution. The range of the pH scale is from 0 to 14.

Question 8

What is water?

Answer 8

Water is the most abundant compound in our bodies and is the main solvent for many of the organic molecules present.

Question 9

What are organic molecules? Give examples.

Answer 9

Organic molecules are often large molecules made up of smaller sub-units that are bonded together in various ways.
Examples of organic molecules would be carbohydrates, proteins, lipids and nucleic acids.

Question 10

What are monomers?

Answer 10

Monomers are small molecules which may be joined together in a repeating fashion to form more complex molecules called polymers.

Question 11

Define carbohydrates

Answer 11

Carbohydrates are organic compounds, composed of carbon (C), hydrogen (H) and oxygen (O). The basic unit of carbohydrates is a sugar molecule.

Question 12

Define simple carbohydrates

Answer 12

Simple carbohydrates contain one or two sugar units causing them to be either monosaccharides or disaccharides.

Question 13

Define complex carbohydrates

Answer 13

Complex carbohydrates contain many sugar molecules causing them to be polysaccharides.

Question 14

What is a monosaccharide?

Answer 14

A monosaccharide is a molecule that comprises a single sugar unit.

Question 15

What is a disaccharide?

Answer 15

A disaccharide is formed when two monosaccharides combine.

Question 16

Define polysaccharides

Answer 16

Polysaccharides are polymers of sugar molecules.

Question 17

What is glycogen?

Answer 17

Glycogen is the form of energy storage in animals

Question 18

Define starch

Answer 18

Starch is a carbohydrate consisting of a large number of glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants as an energy store.

Question 19

Define cellulose

Answer 19

Cellulose is a structural polysaccharide.

Question 20

Define proteins

Answer 20

Proteins are organic compounds that contain the element nitrogen as well as carbon, hydrogen, and oxygen. Proteins are the most diverse group of biologically important substances and are often considered to be the central compound necessary for life.

Question 21

Define amino acids

Answer 21

Amino acids are the building blocks of all biological proteins. Amino acids link together via peptide bonds in a particular order as defined by genes.

Question 22

What is the primary structure of proteins?

Answer 22

The primary structure of proteins is the specific linear sequence of amino acids in the protein.

Question 23

What are the secondary structures of proteins?

Answer 23

There are regions within long protein chains that are organised into structures known as alpha-helices and beta pleated sheets.

Question 24

What does tertiary structure for proteins refer to?

Answer 24

The tertiary structure refers to the total irregular folding held together by ionic or hydrogen bonds forming a complex shape e.g. myoglobin.

Question 25

What is quaternary structure for proteins refer to?

Answer 25

Quaternary structure describes a structure in which two or more polypeptide chains interact to form a protein the resulting structure can be e.g. a globular as in haemoglobin.

Question 26

What is the function of a structural protein? Give an example.

Answer 26

Fibrous support tissue in skin, bone, tendons, cartilage, blood vessels, heart valves and the cornea of the eye. For example collagen and keratin.

Question 27

What is the function of an enzyme? Give an example.

Answer 27

Enzymes catalyse reactions, e.g. ATP synthase.

Question 28

What is the function of contractile proteins? Give an example.

Answer 28

They cause muscle movement, e.g. Myosin and actin.

Question 29

What is the function of immunoglobulin proteins? Give an example.

Answer 29

They defend against diseases, an example would be antibodies.

Question 30

What are conjugated proteins?

Answer 30

A conjugated protein is a protein that functions in interaction with other (non-polypeptide) chemical groups attached by covalent bonding or weak interactions. Many proteins contain only amino acids and no other chemical groups, and they are called simple proteins.

Question 31

What is insulin?

Answer 31

Insulin is produced by beta cells in the pancreas, it’s a protein hormone that controls the level of glucose in the blood by facilitating the uptake of glucose from the blood into tissue cells.

Question 32

What are lipids?

Answer 32

Lipid is the general term for fats, oils and waxes. They have little affinity for water.

Question 33

What are fats made up of?

Answer 33

A fat molecule is made up of two kinds of molecules: fatty acids and glycerol.
Fats and other compound insoluble in water are hydrophobic because the fatty acid have little or no attraction for water.

Question 34

What are phospholipids?

Answer 34

Phospholipids are a type of fat that have two fatty acids attached to a glycerol molecule. They also have a phosphate group attached to a glycerol molecule to make other kinds of phospholipids.

Question 35

What are nucleic acids?

Answer 35

A complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.

Question 36

What is DNA?

Answer 36

Deoxyribonucleic acid, which is located in chromosomes in the nucleus of eukaryotic cells. It is the general material that contains hereditary information and is transmitted from generation to generation.

Question 37

What is RNA?

Answer 37

Ribonucleic acid, is a polymer of nucleotides, it differs from DNA in that it is an unpaired chain of nucleotide bases and consists in three different forms.