2.1 METABOLIC MOLECULES

Question 1

organic compound

Answer 1

contains carbon and is found in living things. exceptions: carbides, carbonates, carbon oxides and cyanides

Question 2

carbon

Answer 2

forms the basics of organic life because it can form large complex molecules via covalent bonding. carbon atoms form 4 covalent bonds.

Question 3

classes of carbon compounds

Answer 3

carbohydrates
lipids
nucleic acids
proteins

Question 4

carbohydrates

Answer 4

most abundant in nature
composed of C, H, and O atoms in common ratio
store of energy
recognition molecule and structural component of DNA and RNA

Question 5

lipids

Answer 5

non-polar, hydrophobic molecules
main component of cell membranes
long term energy storage molecules
signaling molecules

Question 6

nucleic acids

Answer 6

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

Question 7

proteins

Answer 7

over 50% of the dry weight of cells.
composed of C, H, O, and N atoms.
regulatory molecules involved in catalysis (enzymes)
structural molecules
cell signalling

Question 8

complex macromolecules may be comprised of…

Answer 8

monomers: small, recurring subunits

Question 9

carbohydrate monomers

Answer 9

monosaccharides
building blocks of disaccharides and polysaccharides
they form ring structures and can exist in different 3D configurations.

e.g. ribose and glucose

Question 10

lipid monomers

Answer 10

no recurring monomer
fatty acid chains instead
these are long chains of hydrocarbons that may or may not contain double bonds
unsaturated has double bonds, saturated does not

Question 11

nucleic acid monomers

Answer 11

nucleotides join to form polynucleotide chains
each contains a pentose sugar, a phosphate group and a nitrogenous base
the type of sugar and composition of bases differs between DNA and RNA

Question 12

protein monomers

Answer 12

composed of amino acids, which form a polypeptide chain.
each consists of a central carbon connected to an amine group and an opposing carboxyl group
amino acids may be polar or non polar

Question 13

carbohydrate polymers

Answer 13

polysaccharides differ according to the type of monosaccharide they possess and the way the subunits bond together
glucose monomers can be combined to form a variety of different polymers

Question 14

lipid polymers

Answer 14

simple lipids - esters of fatty acids and alcohol (e.g. triglycerides and waxes)
compound lipids - esters of fatty acids, alcohol and additional groups
derived lipids - substances derived from simple and compound lipids

Question 15

nucleic acid polymers

Answer 15

nucleotides form bonds between the pentose sugar and phosphate group to form long polynucleotide chains
in DNA, two complementary chains will pair up via hydrogen bonding between nitrogenous bases to form double strands
the double stranded molecule may twist to form a double helix arrangement

Question 16

protein polymers

Answer 16

amino acids join by peptide bonds which form between amine and carboxyl groups of adjaced amino acids.
the fusion creates a dipeptide, with further additions resulting in a polypeptide chain
the folding of the chain depends on the order of amino acids in a sequence

Question 17

vitalism

Answer 17

this theory dictated that organic molecules could only be synthesised by living systems. it was believed that all living things possessed a “vital force” needed to make organic molecules

Question 18

how was vitalism falsified

Answer 18

in 1828, Frederick Woehler heated an inorganic salt and produced urea, a waste product of nitrogen metabolism which is eliminated by the kidneys in mammals. the artificial synthesis of urea demonstrates that organic molecules are not fundamentally different to inorganic molecules.

Question 19

metabolism

Answer 19

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

Question 20

2 key functions of metabolism

Answer 20

1. provide source of energy for cellular processes.
2. enable the synthesis and assimilation of new materials for use within the cell

Question 21

anabolic reactions

Answer 21

the set of metabolic reactions that build up complex molecules from simpler ones. occur via condensation reactions

Question 22

condensation reactions

Answer 22

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

Question 23

monosaccharides condensation reaction

Answer 23

joined via glycosidic linkages to form disaccharides and polysaccharides.

Question 24

amino acids condensation reactions

Answer 24

joined via peptide bonds to make polypeptide chains

Question 25

glycerol and fatty acid condensation reaction

Answer 25

joined via an ester linkage to create triglycerides

Question 26

nucleotides condensation reaction

Answer 26

joined by phosphodiester bonds to form polynucleotide chains

Question 27

anabolism: purpose, energetics, and mechanism

Answer 27

purpose: synthesizing complex molecules from simpler ones
energetics: uses energy to construct new bonds
mechanism: typically involves reduction reactions

Question 28

catabolic reactions

Answer 28

the set of metabolic reactions that break complex molecules down into simpler molecules. typically occurs via hydrolysis reactions.

Question 29

catabolism: purpose, energetics, and mechanism

Answer 29

purpose: breaking down complex molecules into simpler ones
energetics: releases energy when bonds are broken
mechanism: typically involves oxidation reactions