Biological Molecules

why is water a polar molecule?

uneven distribution of charge within the molecule

how are hydrogen and oxygen atoms held together in water?

covalent bonds

what is a hydrogen bond

a weak electrostatic force of attraction between slightly positively charged hydrogen of one water molecules with slightly negatively charged oxygen of another

what are the 5 roles of water in living organisms

solvent,temperature buffer,habitat,metabolite,transport medium

why is water know as the universal solvent

it dissolves more substances than any other liquid

why is water being a good solvent useful

most biological reactions take place in solutions and dissolved substances can be transported around the body

what does it mean for water to have a high specific heat capacity

a lot of energy is required to raise the temperature of water

why does water have a high specific heat capacity

there are many hydrogen bonds between water molecules which can absorb lots of energy before breaking

how does a high specific heat capacity benefit living organisms

maintains a fairly stable temperature as their bodies are made up of mostly water

what does it mean for water to have a high latent heat of vaporisation

a lot of energy is required to break the hydrogen bonds to change water from a liquid to a gas

why is a high latent heat of vaporisation important for living organisms

allows organisms to use evaporation as a method of cooling without losing too much water

why is water a suitable habitat for many organisms

has a high specific heat capacity and high latent heat of vaporisation which means it doesn’t change temperature or evaporate easily

why does ice float on water

ice is less dense than water due to the water molecules being further apart from one another

why is ice important for organisms living in bonds and lakes

it forms an insulating later that prevents the water below from freezing

what is cohesion

the tendency of water molecules to stick together

how does cohesion help transport water in plants

water forms a continuous column up the xylem driven by transpiration pull without the column breaking

what is adhesion

the tendency of water molecules to stick to other materials

what is the role of adhesion in plants

helps the water cling to xylem walls

what is capillary action

process where water can rise up a narrow tube against the force of gravity

what type of chemical reaction uses water to break down molecules

hydrolysis

what causes high surface tension in water

stronger cohesive forces between surface water molecules than with air molecules above

what elements make up carbohydrates

carbon,hydrogen,oxygen

what is a monomer

smaller units from which larger molecules are made

give 3 examples of a monomer

monosaccharide, amino acids and nucleotides

what is a polymer

large molecules made from many monomers joined together in a chain

give 3 examples of a polymer

polysaccharide,polypeptide,polynucleotide

what’s a condensation reaction

when 2 molecules are joined together with the formation of a chemical bond with water as a by product

what’s a hydrolysis reaction

when a chemical bond between 2 molecules is broken using water

what type of bond is formed from 2 monosaccharides

glycosidic