3 molecules in living organisms
carbohydrate
proteins
lipids
chemical elements of carbohydrates
carbon, hydrogen, and oxygen (CHO)
chemical elements of proteins
carbon, hydrogen, oxygen, nitrogen (CHON) (sometimes nitrogen and phosphorus)
chemical elements of lipids
carbon, hydrogen, oxygen (CHO)
structure of carbohydrates
polymers that break down into simple sugars
structure of protein
polymers that break down into their monomers: amino acids
structure of lipids
large polymers that break down into 3 fatty acid molecules and a glycerol molecule
enzymes
biological catalysts, usually proteins whose shape is vital to their function.
biological catalysts
substances that speed up a reaction without being changed itself
structure of enzyme
each enzyme has its own uniquely shaped active site and substrate
lock and key hypothesis
shape of substrate complements active site so the bound reacts and products are released from enzyme surface
factors affecting enzyme activity
temperature and pH
temperature
optimum temperature (37 degrees C)
rate of reaction increases with an increase in temperature up to optimum
above optimum, rate of reaction decreases and eventually stops
enzyme becomes denature above optimum
denatured enzyme
when the temperature is too hot, the bonds in the structure break.
changed shape of active site and substrate can no longer fit in
enzyme no longer works
pH
optimum pH (7)
too high or low pH will affect the amino acids that make up the protein
this changes the shape the active site and denatures the enzyme
monosaccharide
simple sugar molecule e.g. glucose, fructose
glucose
glucose molecules contain lots of energy which can be released in respiration by breaking the bonds between the carbon atoms
disaccharide
made when 2 monosaccharides join together e.g. maltose, sucrose
maltose
2 glucose molecules
sucrose
1 glucose and 1 fructose molecule
polysaccharide
formed from many monosaccharides e.g. starch, glycogen, cellulose
polysaccharide formation
insoluble and useful as storage molecules
triglyceride
a lipid made of three fatty acid molecules and one glycerol molecule