Biological molecules Flashcards
what do molecules in living organisms contain
carbohydrates
proteins
lipids
what elements do carbohydrates contain
C, H, O
What is a monosaccharide + examples
simple sugar
- glucose and fructose
What is a disaccharide + examples
when 2 monosaccharides join together
what does maltose contain
two glucose molecules
what does sucrose contain
one glucose and one fructose molecule
What is a polysaccharide + examples
when lots of monosaccharides join together
- starch, glycogn and cellulose
why are polysaccharides used as storage molecules
insoluble
what are most fats made up of
triglycerides
what do fats contain
one glycerol chemically bonded to 3 fatty acid chains
2 types of lipids
fats and oils
what are proteins made up from
long chains of amino acids
who many amino acids are they
20
examples of proteins
enzymes
haemoglobin
what determines a proteins function
its shape
how do enzymes work
- they have a specifically shaped active site
- for a specific substrate
- if shape of active site does not fit the reaction does not take place
test for glucose
- add Benedicts solution
- heat in boiling water bath for 5mins
- take test tube and observe color
- positive test= blue to brick red
test for starch
- add drops of iodine solution
- positive test= orange to blue black
test for protein
- add drops of bieuret solution
- positive test= blue to lilac
test for lipids
- mix 4cm3 of ethanol and shake
- strain ethanol solution into other test tube
- add the ethanol solution to equal volume of cold distilled water
- positive test= cloudy emulsion forming
safety test for protein test
- wear goggles because biuret solution contains copper (II) sulfate
- biuret is corrosionve
what are enzymes
biological catalyst to speed up the rate of reaction without being changed or used up
enzyme-substrate complex
when substrate moves into the enzymes active site
what is an enzymes optimum temperature in human body
37
denaturation
heating enzymes to high temperatures will break the bonds that hold the enzyme together at it will lose its shape
what happens when raising the temperature of the enzymes
- enzymes gain more kinetic energy so the molecules move faster and the number of collisions with the substrate molecules increases
- leads to faster rate of reaction
why do enzymes at low temperatures work slowly
lack of kinetic energy
what is the optimum pH for most enzymes
7
what is the pH of enzymes in the stomach
2
pH of enzymes in the duodenum
9
what happens if pH is too high or low
the bonds that hold the amino acid chain together can be disrupted/destroyed
- changed the shape of active site
