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55 Cards in this Set
- Front
- Back
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what is selective media?
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favor the growth of one species
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What is defined media?
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known ingredients (chemical composition) that can be manipulated
precisely defined growth requirements of different species |
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How many streaks must you made in order to get isolated colonies on the vibrio plate?
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a min of 3 streaks, the last one being the biggest one
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For part 1 of the experiment, in what order and volume do you add ingredients?
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1- .5 ml of enzymes at various conc
2- 1.0 ml 4% starch 3- add DNS |
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What is the order for adding ingredients for the blank?
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1-.5 ml of enzymes at any conc
2-add 1ml DNS 3- 1.0 ml 4% starch |
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How long do you have to wait for the reaction to proceed before adding DNS?
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5 minutes
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How long do yo have to heat up the test tubes to get the brown products?
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7 minutes
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What's the temperature need to heat up the test tubes to get the brown products?
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95 degree C or greater
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What's the absorbance of 1 um maltose solution?
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O.D of 0.4
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When using the spectrophotometer, do you use the blank or sample first?
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the blank
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At what wavelength do you set the spectrophotometer to?
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510 nm
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For the temperature experiment, what do you have to do .5ml of E and 2.0ml of S?
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equilibrate them separately - set them at the given temp
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Do you need multiple blanks for the temperature experiment? Why?
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No you only need one blank like the one from part 1 because the concentration of starch and enyzme remain the same through out.
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Do you need multiple blanks for the Km experiment? Why?
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Yes because each test tube have a diff concentration of starch - start with diff background.
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Do you need multiple blanks for the saliva experiment? Why?
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No only one blank at any dilution because there's few reducing units in saliva.
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Do you need multiple blanks for the pH experiment? Why?
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Yes because different pH break down diff enzyme at diff rate.
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What are the two functions of DNS?
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1-extreme alkalinity to denatures amylase
2-allows measurement of starch disappearance and maltose appearance |
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what happen to starch in this lab?
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starch are hydrolyzed by amylase into maltose
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where do you dispose of your solutions?
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small "waste" beaker at station then at end empty beaker at larger "waste" bucket
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What do you use to wash test tubes?
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use a test tube brush
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how do you wash spec 20 tubes?
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rinsed w/ de-ionized water at least 5 times at sink
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What is the Km value?
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the amount of substrate at which the enzyme is operating at one-half its max velocity (Vmax)
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What's the relationship between affinity and Km?
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affinity=1/Km
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define affinity?
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likeness or attraction between substances
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what's the function of enzymes in cell?
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catalyze most cellular reactions
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how do cells regulate reactions?
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by regulating the production & activity of enzymes
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define exergonic?
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release free energy
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define endergoinic?
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products have more free energy than substrates- gain free energy
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what are two ways to increase reactions?
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1-inc temp
2-lower activation energy |
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what are monosaccharides?
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carbohydrates made of only one simple sugar
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what are polysaccharides?
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polymers of many simple sugar (multiple monosaccharides)
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what's the process of carbohydrate metabolism?
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basic unit glucose is converted to polysaccharides to store chemical energy in the cell and then reconverted into glucose
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in plant what is the excess glucose?
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starch granules
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what is glycogen?
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excess glucose in animals
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what's the difference between glycogen and starch?
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diff in bonds that connect glucose subunits
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what do the enzyme almylase do ?
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hydrolyze starch into smaller polysaccharides
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what is "maltodextran"?
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mix of maltose and various sizes of starch
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what is phosphorylase?
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enzymes in the liver and muscles that breaks down glycogen
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what is glycogen sythetase?
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enzymes that synthesizes glycogen in the liver and muscles
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where are alpha-amylases common in?
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plants and animals
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where are beta-amylases located?
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only plants
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define isoenzymes (isozymes)?
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various forms of the same enzyme
i.e structure and catalytic characteristics because located in diff organs |
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describe the structure of starch?
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glucose units hooked together to form linear molecules that tend to form helical spirals
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describe the structure of glycogen?
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short pieces of linear polymers hooked together in a branching patter, too short to form spirals
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what type of polymers do amylase attacks faster?
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faster at breaking bonds to split a large polymer than a small one
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where is the reducing unit on the maltose molecule?
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the terminal glucose
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what happen to the amount of reducing units as hyrolysis of starch proceeds?
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reducing units increase
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what happen to the amount of product as concentration of substrate increase?
why? |
amount of product inc bec enzyme work at max velocity
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what's the effect of enzyme concentration on amount of product?
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amount of product increase
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what indicate a high affinity or high sensitivity?
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high reaction rate w/a very low concentration of substrate
high Km |
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what indicate a low affinity or low sensitivity?
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enzyme behaves as if there's no substrate around
low reaction rate w/a very high or average concentration of substrate low Km |
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what is the Principle of Le Chatelier?
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if heat is given off in the forward direction then increasing the temperature drives the backward reaction and vice versa
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what do temp affect ?
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the shape of proteins (effect on intramolecular bonds) and enzyme activity
low temp- affect enzyme-substrate affinity |
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what's the effect of high temperature on enzyme?
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denaturation process
enzymes loses activity as its shape changes |
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what are the effects of pH?
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1-may cause denaturation of the enzyme
2-may affect reaction rates w/o causing denaturation |
