Biological molecules Flashcards
what is hydrogen bonding?
a hydrogen bond is a weak interaction that occurs between a slightly negatively charged atom and a slightly positively charged atom
list 4 important functions of water inside and outside of the cells
reactant in most chemical reactions - hydrolysis
solvent- substances can dissolve in it as most biological reactions take place in solution
its a habitat- helps with temperature control, less dense when freezes so many organisms can survive and reproduce in it
transports substances- its a liquid and solvent so easily transports all sorts of material around animal and plant cells.
how is waters structure related to its functions?
hydrogen bonds give water a high specific heat capacity- hydrogen bonds between water molecules can absorb lots of energy so water takes a lot of energy to heat up meaning it does not experience rapid temperature changes making it a good habitat.
hydrogen bonds give it a high latent heat of evaporation- takes a lot of energy to break hydrogen bonds between water molecules, so a lot of heat is used up when water evaporates meaning waters great for cooling things as we sweat when we are hot and when sweat evaporates it cools the surface of the skin
waters polarity makes it a good solvent- ions can be be dissolved as the slightly positive end of a water molecule will be attracted to a negative ion and vice versa. (important ions can dissolve in water in blood and be transported around the body
water is less dense when it freezes- water molecules are held further apart in ice as it forms 4 H bonds with other water molecules making a lattice structure so ice floats. it forms an insulating layer on top of water so water does not freeze.
what is specific heat capacity?
is the energy needed to raise the temperature of 1 gram of a substance by 1 degree
what is glucose
it is a monosaccharide with six carbon atoms, hexose monosaccharide
what is a ribose
is a monosaccharide with five carbon atoms, pentose monosaccharide
what do all carbohydrates contain?
carbon, hydrogen and oxygen
what are monosaccharides joined together by?
glycosidic bonds
what is sugar a general term for
monosaccharides and disaccharides
condensation reaction
a hydrogen atom on one monosaccharide bonds to a hydroxyl group OH on the other, releasing a molecule of water.
hydrolysis reaction
a molecule of water reacts with the glycosidic bond, breaking it apart
what glucose molecules from maltose?
2 alpha molecules
what glucose molecules form sucrose?
alpha glucose and fructose
what glucose molecules form lactose?
either alpha glucose or beta glucose and galactose
name 3 polysaccharides
starch
glycogen
cellulose
what is the structure and function of starch
starch is a mixture of 2 polysaccharides of alpha glucose, amylose and amylopectin
starch is the main energy storage material in plants. its insoluble in water so it does not cause water to enter cells by osmosis which can make them swell ideally making them good for storage
what is the structure and function of amylose?
long, unbranched chain of alpha glucose the angles of glycosidic bonds give it a coiled structure
compact, good for storage as a lot can fit in small spaces
what is the structure and function of amylopectin?
a long, branched chain of alpha glucose.
its side branches allow the enzymes that break down the molecule to get at the glycosidic bonds easily, meaning glucose can be released quickly.
what is the structure and function of glycogen?
the main energy storage material in animals
polysaccharide of alpha glucose and its structure is similar to amylopectin but has a lot more side branches, more branches=more glucose can be released quickly. very compact
what is the structure and function of cellulose?
the major component of cell walls in plants
made of long, unbranched chains of beta glucose and the cellulose chains are linked together by hydrogen bonds to from strong fibres called microfibrils, means cellulose provides structural support for cells.
what are triglycerides?
are a kinds of lipid, macromolecules
what bonds do triglycerides contain?
they contain ester bonds
how many molecules of glycerol and fatty acids do triglycerides have
1 molecule of glycerol and 3 fatty acids