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Biology Lab Quiz 2
labs 4, 5, 6, 7
34
Biology
Undergraduate 2
03/10/2012

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Term
define catalyst
Definition
something that speeds up the rate of a chemical reaction without being used up or changed in the process
Term
How does a catalyst speed up a chemical reaction
Definition
it lowers the activation energy required for the reaction to occur
Term
define energy barries
Definition
the activiation energy that must be overcome for a chemical reaction to proceed
Term
define enzymes
Definition
biological catalysts that allow the chemical reactions of living organisms (metabolic reactions) to proceed smoothly and efficiently. Usually globular proteins that are highly specific in the reactions they will catalyze.
Term
define thermal optimum as it pertains to enzymes
Definition
the tempurature range at which the enzyme works most efficiently
Term
define pH optmum
Definition
the pH range at which an enzyme works most efficiently
Term
define denature
Definition
the deactivation of enzymes by temperatures above their thermal optimum.
Term
define irreversible denaturation
Definition
permenant, tertiary structure changes to enzymes that occur when temperatures are too high outside the enzymes thermal optimum range
Term
Who do temps and pHs above and below optimal levels inactive enzymes?
Definition
they alter the hydrogen bonding of the alpha helix
Term
what do certain poisons (mercury) do to enzyme
Definition
block their functions
Term
Are enzymes vital for life?
Definition
yes
Term
Introduced in 1878 from the Greek word "in yeast"
Definition
enzyme
Term
simplest bacterium has _____ enzymes
Definition
1,000+
Term
define proteolytic
Definition
protein splitting
Term
how does papain tenderize steak
Definition
it predigests it
Term
List two processes that enzymes are used for outside the body
Definition
tenderizing food and cleaning
Term
the hdrolysis of sucrose is a
Definition
enzyme-catalyzed reaction
Term
What part of an enzyme fits with the substrate?
Definition
the active site
Term
name two features of modern enzyme noenclature
Definition
1. the name corresponds to the sustrate name (sucrose), the name ends in "ase"....sucrase for sucrose.
Term
define cheese
Definition
the solid portion (curd) of milk that has been separated from the liquid portion (whey)
Term
define curd
Definition
primarily a protein (casein) and milk fat
Term
list two different kinds of cheese producation
Definition
sour-milk and rennet
Term
define sour milk production
Definition
controlled souring of milk permits goagulation and separation of the whey from the casein
Term
define rennet cheese production
Definition
milk is coagulated or curdled by an enzymatic process.
Term
define rennin
Definition
enzyme extracted from fourth stomach of unweaned calves and used in chees production
Term
what is rennin replaced by a few weeks after the birth
Definition
pepsin
Term
defin rennet
Definition
a brine extract of rennin from the stomach of 2-4 week old calves
Term
What keeps caseins in solution in uncoagulated milk?
Definition
kappa casein
Term
What does rennet do to kappa casein?
Definition
in breaks it into two parts, causing them to precipitate out of the milk solution which leads to coagulation, shortening the casein protein, squeezing water out and trapping the fat globules
Term
List the 8 steps in cheese making
Definition
1. culturing (acidification) 2. Coagulation 3. Cutting 4. Cooking 5. Firming 6. Draining 7. Pressing 8. Aging
Term
define pancreatic lipase
Definition
an enzyme that is secreted by the pancrease into the duodenum (upper small intestine). It catalyzes the hydrolysis of fat molecules into their component parts too allow absorbstion into the bloodstream. Optimal pH of 8
Term
define bile
Definition
secreted into the duodenum by the liver and stored i the gallbladder. its alkalinity helps to neutralize acids from the stomach and contributes to an intestinal pH of 8, wich is optimal for lipase activity. Also emulsifcation of fat to assist in digestion
Term
describe emulsification
Definition
breaking down of large droples into very tiny droplets NOT DIGESTION. aids digestion by exposing more fat molecules to the lipase so the enzyme can hydrolyze them faster
Term
How does disgetion differ from emulsification?
Definition
digestion breaks down molecules, emulsification separates large drops of molecules into smaller drops of molecules, but the molecules remain whole.
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