Topic 3.1 Chemical Elements and Water Flashcards
What are the most frequently occurring chemical elements in living things?
carbon, hydrogen, oxygen and nitrogen.
State the role of sulfur.
in some amino acids.
States five elements that are needed by living organisms.
SIP Salty Cola:
Sulfur, calcium, phosphorus, iron and sodium.
State the role of calcium.
cofactor in some enzymes and component of bones.
State the role of phosphorus.
phosphate groups in ATP.
State the role of iron.
in cytochromes and in hemoglobin.
State the role of sodium.
in membrane function and sending nerve impulses.
Outline the thermal properties of water.
high specific heat: can absorb and release Great amount of heat without changing temperature greatly
high heat of vaporization: water absorbs great deal of heat to break hydrogen bonds when it evaporates
high boiling point: 100°C to change from liquid to gas; all hydrogen bonds you to be broke
outline the cohesive properties of water.
- Molecules of the same type are attracted to each other due to polar covalent bonding.
- Water molecules will also tend to stick to other molecules that are charged or polar (adhesion)
outline the solvent properties of water.
- excellent solvent of other polar molecules (like dissolves like)
- Majority of molecules typically found inside and outside of cell are polar molecules; most organisms have special strategies to manage transport and biochemistry of non-polar lipids
- Water is an excellent medium in which most or the biochemistry of a cell occurs
explain the relationship between the properties of water and its uses in living organisms as a coolant.
thermal – specific heat: all living things are composed of great deal of water; water is relatively stable in temperature; prevents organism from being too hot or too cold.
thermal – heat of vaporization: plants and animals use evaporation of water from surfaces of bodies to facilitate cooling (sweating in animals, transpiration in plants
explain the relationship between the properties of water and its uses in living organisms as a medium for metabolic reactions.
solvent: water can dissolve many substances to facilitate chemical reactions.
thermal - boiling point: most cases is below boiling point and above freezing point on earth; therefore liquid, therefore good medium.
explain the relationship between the properties of water and its uses in living organisms as a transport medium.
cohesion: strong pulling forces can be exerted to suck columns of water up the roots of a plant in their transport systems; vascular tissue implants carries water and variety of dissolve substances.
solvent: solvent properties of water allow many substances to be carried (dissolved) in water in the blood of animals and the sap of plants.
thermal – specific heat: blood can carry heat from warmer parts of body to cooler parts.
