Biological Molecules

Question 1

What is metabolism

Answer 1

All of the chemical reactions that occur within an organism’s cells

Question 2

What is monomer

Answer 2

Small chemical unit that makes up a polymer

Question 3

What is polymer

Answer 3

Large molecule formed from combination of many monomers bonded together

Question 4

What are the examples of monomers

Answer 4

Monosaccharides, amino acids and nucleotides

Question 5

What are the examples of polymers

Answer 5

Carbohydrates, proteins and nucleic acids

Question 6

What is condensation reaction

Answer 6

A reaction in which two molecules become bonded to each other through the loss of water

Question 7

What is hydrolysis reaction

Answer 7

A chemical reaction that breaks apart a larger molecule by adding a molecule of water

Question 8

Monosaccharides examples

Answer 8

Glucose, fructose, galactose

Question 9

The properties of monosaccharides

Answer 9

Soluble in water
Sweet-tasting
Form crystal

Question 10

Disaccharide examples

Answer 10

Maltose, sucrose and lactose

Question 11

What is polysaccharide and the examples

Answer 11

Carbohydrates that are made up of more than two monosaccharides
Starch, glycogen, cellulose function of starch energy storage in plants

Question 12

Structure and function of starch

Answer 12

Made from Amylose and Amylopectin. Amylose is a long straight chain of alpha glucose which is coiled. Amylopectin is a straight chain of alpha-glucose with side branches ( 1,6-glycosidic bond)
Insoluble - which means it doesn’t affect osmosis-good for energy storage in plants e.g in seeds & storage organs, such as potato cells- coiled so compact, lots of alpha glucoses stored in a small space. Can be hydrolysed to release alpha glucose for respiration

Question 13

Function and structure of glycogen

Answer 13

F: good for energy storage in animals e.g muscle and liver cells can be hydrolysed to release alpha glucose for respiration
S: straight chain of alpha-glucose (1,4-glycosidic bond) with side branches (1,6- glycosidic bond). Shorter and more highly branched

Question 14

Triglycerides

Answer 14

An energy-rich compound made up of a single molecule of glycerol and three molecules of fatty acid

Question 15

Phospholipid

Answer 15

A lipid that contains phosphorus, 2 fatty acids and one glycerol and is structural component in cell membrane

Question 16

Function of lipids
Saturated triglycerides & unsaturated fatty acid

Answer 16

F: insulation, energy storage, structural (cholesterol and phospholipid in membrane), protection, non-polar
ST: no double carbon bonds composed of saturated fatty acids, typically have high melting points, tend to be hard at room temperature
USF: a fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to carbon skeleton

Question 17

Hydrophobic and hydrophilic

Answer 17

Water hating (fatty acids) and water loving ( phosphate head)

Question 18

Functions of proteins
Polar and Non- polar

Answer 18

Structural support, catalyst, hormones, antibodies and enzymes
Polar-molecule with partial charges and mixes with water
Non-polar: equal sharing of electron, no charge

Question 19

What are the levels of protein structure

Answer 19

Primary protein structure: sequence of amino acids
Secondary protein structure: coiling or folding of a polypeptide due to H-bonding between amino acids. Alpha helices or beta pleated sheets
Tertiary structure: the third level of protein structure; the overall, three dimensional shape of a polypeptide due to interaction of the R groups of the amino acids making up the chain. Held together by hydrogen bonds, disulphide bridges and ionic bonds

Question 20

What are other level of protein

Answer 20

Quaternary structure: the fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits
Haemoglobin structure: large, globular conjugation protein made of four polypeptide chains,each with an iron-containing haem groups
Collagen structure: 3 proteins chains twisted into a triple helix. High glycine and proline content. Cross links tie fibres together

Question 21

What are globular and fibrous protein and glycoproteins (function)

Answer 21

Globular proteins are spherical, water- soluble proteins
Fibrous proteins: long, insoluble, structural proteins
Glycoproteins: A protein with one or more covalently attached
Functions: acts as recognition sites, help cells to attach to one another and so form tissues, allows cells to recognise one another

Question 22

Nucleic acids

Answer 22

DNA stands for: deoxyribonucleic acid
RNA stands for: ribonucleic acid
The monomers of nucleic acid are called: nucleotides
3 components of a nucleotide: sugar, phosphate and base
Adenine and thymine, guanine and cytosine. The bond formed between the adjacent nucleotides are phosphodiester bonds

Question 23

DNA

Answer 23

consists of two long, chains of nucleotides twisted into a double helix and joined by hydrogen bonds between complementary bases adenine and thymine or guanine and cytosine. Long molecule which stores a lot of genetic info in a small space

Question 24

RNA structure

Answer 24

*short and single stranded
*ribose sugar, bases are A,U,C,G
* nitrogenous base and a phosphate group.
3 types of RNA: mRNA , tRNA and rRNA

Question 25

mRNA and tRNA
ATP structure

Answer 25

messenger RNA: Every 3 bases is called a codon. It is RNA molecule that carries copies of instructions for the assembly of amino acid into proteins from DNA to the rest of the cell
Transfer RNA: type of RNA molecule that transfers amino acids to ribosomes during protein synthesis. It has an amino acid binding site and a anticodon.
ATP: adenine, ribose and 3 phosphate groups. Can be used in phosphorylation, active transport, metabolic processes , exocytosis and movement.