Metabolic Molecules

Question 1

what is molecular Biology?

Answer 1

Molecular Biology is a field of study that focuses on investigating biological activity at a molecular level

Question 2

biological process

Answer 2

Biological processes are tightly regulated by enzymes whose expression is controlled by gene activation. Changes in activity are typically determined by signalling molecules

Question 3

organic compounds

Answer 3

An organic compound is a compound that contains carbon and is found in living things
(exceptions: Carbides, carbonates, oxides of carbon and cyanides)

Question 4

Carbon

Answer 4

Carbon forms the basis of organic life due to its ability to form large and complex molecules via covalent bonding

Question 5

4 main groups of organic compounds

Answer 5

1) Carbohydrates
2) Lipids
3) Nucleic acids
4) Proteins

Question 6

Carbohydrates

Answer 6

• most occurring
• functions as a source of energy
• Important as a recognition molecule and structural component

Question 7

Lipids

Answer 7

• Non polar, hydrophobic molecules
• may come in a variety of forms (simple, complex, derived)
• serve as a major component of cell membranes (phospholipids and cholesterol)
• long term energy storage (fats and oils)
• signalling molecule (steroids)

Question 8

Nucleic acids

Answer 8

• genetic material of all cells and determines the inherited features of an organism
• DNA functions as a master code for protein assembly, while RNA plays an active role in the manufacturing of proteins

Question 9

Proteins

Answer 9

• Make over 50% of the dry weight of cells (composed of C,H,O and N atoms)
• all enzymes are proteins, so molecules involves in catalysis
• may function as a structural molecule or play a role in cellular signalling

Question 10

monomers

Answer 10

complex macromolecules that are comprised of smaller recurring subunits

Question 11

examples of monomers joined to form larger polymers

Answer 11

1) Carbohydrates
2) Nucleic acids
3) Proteins
not Lipids (Fatty acids and Monoglycerides)

Question 12

Monosaccharides

Answer 12

Carbohydrates are composed of monomers called Monosaccharides, they are:
- building blocks of disaccharides and polysaccharides
- most monosaccharides form ring structures and can be 3D

Question 13

examples of common Monosaccharides

Answer 13

1) Ribose
2) Glucose alpha
3) Glucose beta

Question 14

why do Lipids not have a recurring monomer?

Answer 14

Lipids exist as many different classes that vary in structure. However several types of lipids (phospholipids) contain fatty acid chains as part of their overall structure

Question 15

Fatty acids

Answer 15

Fatty acids are long chains of hydrocarbons that may or may not contain double bonds (unsaturated vs saturated)

Question 16

Amino Acids

Answer 16

Proteins are composed of monomers called amino acids which join together to form polypeptide chains

Question 17

nucleic Acids

Answer 17

Nucleic acids are composed of monomers called nucleotides, which join together to form polynucleotide chains. Each Nucleotide consists of 3 components: A pentose sugar, A phosphate group, A nitregenous base

Question 18

Carbohydrates

Answer 18

the structure of complex carbohydrates may vary depending on the composition of monomeric subunits.

Question 19

Glucose monomers

Answer 19

They can be combined to form a variety of different polymers including glycogen, cellulose and starch

Question 20

Polymers of Glucose

Answer 20

Liver tissue = Glycogen (in granules)
Leaf tissue = Cellulose (in cell wall) and Starch
(in granules)

Question 21

Lipids

Answer 21

Lipids can be roughly organised into one of three main characters

Question 22

three main types of Lipids

Answer 22

1) Simple lipids =Esters of fatty acids and alcohol (triglycerides)
2) Compound lipids = Ester of faty acids, alcohol and additional groups (phospholipids)
3) Derived lipids = Substances derived from simple or compound lipids (steroids)

Question 23

Proteins

Answer 23

Amino acids join together by peptide bonds which form between the amine and carboxyl groups of adjacent amino acids.

Question 24

Dipeptide

Answer 24

The fusion of two amino acids + water creates a dipeptide

Question 25

Nucleic acids

Answer 25

Nucleotides form bonds between the pentose sugar and phosphate group to form long polynucleotide chains

Question 26

Polynucleotide chains

Answer 26

Nucleotides form bonds between the pentose sugar and phosphate group to form a long polynucleotide chain.

Question 27

Double Helix

Answer 27

when two complementary chains (polynucleotide) pair up via hydrogen bonding between nitrogenous bases to form a double helix

Question 28

vitalism theory

Answer 28

Vitalism was a doctrine that dictated that organic molecules could only be synthesised by living systems.
It has been disproven

Question 29

Frederick Woehler

Answer 29

In 1828 he disproved the theory by producing urea from inorganic salt

Question 30

Urea

Answer 30

It is a waste product of nitrogen metabolism and is eliminated by the kidneys in mammals

Question 31

Metabolism

Answer 31

Metabolism describes the totality of chemical processes that occur within a living organism in order to maintain life.
It is the web of all enzyme catalysed reactions that occur within a cell or organism

Question 32

Anabolic reactions

Answer 32

Anabolic reactions are the set of metabolic reactions that build up complex molecules from simpler ones. The synthesis of organic molecules via anabolism typically occurs via condensation reactions

Question 33

Condensation reactions occur:

Answer 33

when monomers are covalently joined and water is produced as a by product

Question 34

via what linkages are the monomers joined

Answer 34

1) Monosaccharide are joined via glycosidic linkages to form disaccharides and polysaccharides
2) Amino acids are joined via peptide bonds to make polypeptide chains
3) Fatty acids and glycerol are joined via an ester linkage to create triglycerides
4) Nucleotides are joined via phosphodiester bonds to form polynucleotide chains

Question 35

Anabolism

Answer 35

Purpose = Synthesizing complex molecules from simpler ones
Energetics = uses energy to construct new bonds
Mechanism = typically involves reduction reactions
Examples = Gluconeogenesis

Question 36

Catabolic reactions

Answer 36

Catabolic reactions describe the set of metabolic reactions that break complex molecules down into simpler molecules. this occurs via hydrolysis reactions which need water molecules to break the bonds within the polymer

Question 37

Catabolism

Answer 37

Purpose = Breaking down complex molecules into simpler ones
Energetics = Release energy when bonds are broken
Mechanism = Typically involves oxidation reactions
Examples = Glycolysis