MODULE 2: Biological Molecules !! Flashcards
Elemental components of carbohydrates:
Carbon, hydrogen, oxygen
Elemental components of lipids:
Carbon, hydrogen, oxygen
Elemental components of proteins:
Carbon, hydrogen, oxygen, nitrogen and sulphur
Elemental components of nucleic acids:
Carbon, hydrogen, oxygen, nitrogen and phosphourous
Formation of polymers:
Biological molecules are often made up of many monomers to form a long chain polymer:
monomer –condensation–> polymer
polymer –hydrolysis–> monomer
Examples of monomers and polymers in biological molecules:
Sugar as a monomer to carbohydrates, amino acids as monomers to proteins
Properties of water:
- High boiling point
- Less dense as a solid
- Cohesive-adhesive properties
Why does water have a high boiling point?
Hydrogen bonding increases the energy required to break the intermolecular forces
Why is water less dense as a solid?
Hydrogen bonds have a fixed position slightly further away than as a liquid, causing an increase in volume but the same mass (D=m/v)
Why does water have cohesive and adhesive properties?
Polarity allows molecules to be attracted to each other and other materials
How is water essential for life?
- Acts as a solvent
- Water acts as a transport medium
- Water acts as a coolant
- Water acts as a habitat
How is water acting as a solvent essential for life? (example needed)
- Polarity of water allows solutes (that are often polar) to be dissolved
- Allows water to act as a medium for chemical reactions
- Aids transport of dissolved substances in and out of cells
E.G. cystol (aqueous component of a cytoplasm) of prokaryotes and eukaryotes mainly water
How is water acting as a transport medium essential for life? (example needed)
- Cohesion and adhesion cause CAPILLARY ACTION, so water (containing dissolved substances) can rise against gravity in narrow tubes
E.G. blood in vessels of multicellular animals, transporting necessary substances (oxygen, waste products)
How is water acting as a coolant essential for life? (example needed)
- Very stable, as does not change temperature easily and is not very volatile
- Therefore, is able to maintain a stable temperature within an organism during environmental changes and in chemical reactions (large amounts of energy used/given out)
- Important to maintain internal temperatures to maintain enzyme activity (active in narrow ranges) that catalyse metabolic processes
E.G. membrane proteins (channel + carrier) for active transport, DNA polymerase and helicase in DNA replication, ATP synthase in respiration
How is water acting as a habitat essential for life? (example needed)
- Very stable, as does not change temperature easily and is not very volatile
- Therefore maintains a temperature that aquatic organisms can live in with little variation despite seasonal changes
- During colder seasons, ice forms- but due to lower density, floats to the top of aquatic environments and forms an insulating layer for the habitats below
- Surface tension also supports small insects walking/travelling on top of the water
E.G. aquatic organisms in lakes/ponds and pond skaters using surface tension
Difference between alpha and beta glucose:
Position of -OH group on carbon one (alpha on bottom, beta on top)
Properties of glucose:
Polar, small and soluble
Hexose monosaccharides:
Fructose, galactose and glucose
Pentose monosaccharides:
Ribose and deoxyribose
Formation of disaccharides/polysaccharides:
Condensation reactions that form a glycosidic bond
Glycosidic bonds:
Covalent bonds that link ring-shaped sugar molecules
Formation of maltose:
Maltose (disaccharide)
glucose + glucose
Formation of sucrose:
Sucrose (disaccharide)
glucose + fructose
Formation of lactose:
Lactose (disaccharide)
glucose + galactose