Bio Chapter 2 Enzymes

Enzymes are:

1.Proteins 2. Organic Catalysts 3. Not effected by reaction 4. Specific

pH of water?

7 that is neutral

Allosteric Site

A site on an enzyme other than the active site where a substance can bind and effect enzyme activity -may either increase or decrease enzyme activity

Fingertips in penny lab are?

Active site

Relationship Allosteric regulation, inhibitor, enhancer, active site, & enzyme

Allosteric regulation is the body's way to regulate enzyme activity. An enzyme will not regulate itself, it will continue to find substrates as long as they are available and increase reaction rates. Allosteric regulation can either inhibit (slow down) or enhance (speed up) enzyme activity. Competitive inhibitors take the place of the substrate at the active site. Noncompetitive inhibitors block the substrate from getting to the active site. Enhancers work by moving the active site closer to the surface of the enzyme thereby increasing the likelihood that a substrate will meet the active site.

Relationship Catalyst, organic catalyst, protein, & enzyme

An enzyme is a specialized protein that acts as a catalyst. This means that it is able to speed up a normally occurring reaction by lowering the activation energy necessary for the reaction to occur. An enzyme is also considered an organic catalyst because it is naturally occurring in living things and can be denatured by changes in pH and temperature or the presence of heavy metal ions.

Relationship Denatured, pH, temperature, organic catalyst, active site, & enzyme

An enzyme is considered an organic catalyst that is found naturally occurring in living things. Organic catalysts are affected by dramatic changes in pH or temperature. When this occurs the active site becomes denatured or changes shape and will no longer function properly because the substrate will not fit together with the enzyme at the active site.

Enzyme Activity

Anything that will effect protein folding will affect enzyme activity. (pH, Temperature, solute concentrations, metal ions) Enzymes are designed to work best under particular circumstances Ex: digestive enzymes designed to work in the acid environment of the stomach.

How do buffers work?

Attempt to maintain homeostasis (keep pH levels the same) Molecules that bond with ions in solution (H+ or OH-) to maintain levels & therefore pH

How do enzymes function?

Bind with a substrate at the active site to either build or break down in order to speed up reaction.

Summary of Enzyme Function lab

Change in temperature & pH impacted the ability or enzymes to function. Enzymes are found naturally in living cells H202 + catalase → H2O + O2 + catalase Enzymes can be re-used (not effected by reaction)

When an enzyme changes shape?

Denatured

How does the term specificity relate to an enzyme?

Each enzyme is specific to one task or substrate. ie lactase only breaks down lactose How does substrate concentration

Relationship Homoeostasis, buffer, pH, denatured, active site, & enzyme

Enzyme function optimally within a specific pH range. The ability of a body to maintain stability under various conditions is homeostasis. Buffers assist with maintaining homeostasis by attaching to free floating Hydrogen ions to keep the pH level stable. If the pH level does not remain stable the active site of the enzyme becomes denatured or changes shape and is no longer functional.

Relationship Enzyme specificity, lactose, lactase, lactose intolerance, & enzyme

Enzyme specificity means that enzymes are specific to or connect with only one substrate. They therefore speed up only one type of reaction. For example, lactase is the enzyme that assists with the breakdown of lactose, a milk sugar. If a person does not have enough lactase then the lactose is not broken down fast enough and stays in the digestive tract longer than it should. This causes a build-up of lactose within the intestinal tract which results in bloating, gas, and intestinal discomfort. If a person has this condition they are considered to be lactose intolerant.

An enzyme that speeds up the breakdown of lactose can also speed up the breakdown of maltose. True or False and why.

False because enzymes exhibit specificity (one work for one kind of substrate)

How does substrate concentration effect the functioning of enzymes (think Penny Lab)?

Greater substrate concentration equals greater enzyme efficiency (easier for them to run into the substrate)

How does an indicator work? Describe an indicator we used in this unit & what it told us.

Indicator changes color to demonstrate the presence of a substance. pH paper - color change indicated the number of pH

Cofactors/Coenzymes

Is a non protein substance an enzyme needs to function -many enzymes require inorganic ions, Zn,Fe,Cu If this is an organic molecule it is called a coenzyme -many vitamins are coenzymes Coenzyme is a type of cofactor.

Higher concentration of H+ Juice pH 2 or Tomatoes pH 4

Juice pH 2

Summary of Penny Lab

Lab 5 - Penny lab = model for enzyme activity Pennies were substrate, hands were enzyme, fingertips were the active site. Blocked or changed the shape of our active site (gloves & tape) lowered their ability to function.

What is it called having a pH of 7

Neutral

Acidity in Enzymes

Pepsin- 2 Salivary Amylase- 6-7 Arginase- 9-10

Describe an enzyme.

Protein that acts as an organic catalyst to speed up naturally occurring reactions by lowering the activation energy needed for the reaction to occur. Because it is an ORGANIC catalyst it is impacted by changes in pH, temperature, & presence of heavy metal ions. It is not affected by the reaction and can be reused over & over again. It is substrate specific - one function.

What is the role of an enzyme?

Speeds up naturally occurring reactions by lowering the activation energy needed for the reaction to occur.

Activation Energy

The energy required to cause molecules to react with one another. Enzymes lower this energy necessary for a reaction to occur.

Buffer

The function of this substance is to minimize the change in pH when an acid or a base is added to the solution.

Rate of Reaction

The rate of reaction depends on the concentration of substrate and amount of enzyme.

Enzyme inhibitors

When as active enzyme is prevented from combining with a substrate. -Enzyme activity must be regulated, if a substance is not needed in a cell, why make it -Many antibiotics inhibit bacterial enzymes but not our own, thus killing bacteria

Enzyme Substrate Complex

When the substrate binds to the enzyme.

Competitive inhibitors

a substance takes the place of the substrate at the active site of the enzyme

Which has a lower pH value, acids or bases

acids

Where does an substrate bind to the enzyme

active site

Your body's way of either speeding up or slowing down enzyme activity is called.

allosteric regulation

Which has a higher concentration of OH- ions, acids or bases?

bases

Noncompetitive inhibitors

bind to the allosteric site on the enzyme and cause a conformational change so the substrate can not bind to the active site.

Allosteric Regulation

bodies way if regulating an enzyme. Inhibits enzyme of working non competitive

General substance that speeds up a reaction

catalyst

3 environmental conditions that effect enzyme functioning

change in pH, temo, and heavy metal ions

The difference between a coenzyme and a cofactor

coenzymes are organic cofactors are inorganic

An increase in substrate ___ can increase the rate of enzyme activity.

concentration

What is pH?

concentration of H+ ions in a solution.

Organic catalyst

found naturally within living cells and can be denatured by change in pH, temp and heave metal ions.

Inorganic catalyst

is synthetic or "made" there is no effect when there is a change in pH, temp, heavy metal ions.

How do enzymes speed up a reaction rate

lower activation energy

Enhancers speed up enzyme activity by doing this during allosteric regulation.

move active site closer to the surface of the enzyme

One of the reasons that allosteric regulation in needed because enzymes .....

never stop working

Can enzymes initiate a reaction that would normally not occur?

no, enzymes only speed up reactions that would otherwise occur normally.

Acid's pH

pH 1-7

Enzymes are what type of macromolecule

protein

Active Site

region of the enzyme that binds to the substrate (reactant), typically only a few amino acids are directly involved.

Substance with a pH of 14 is a

strong base

Components of Equation: H2O2 + catalase -> H2O+ O2+ catalase

substrate+enzyme->products+enzyme

What type of bonds hold an enzyme substrate complex together

weak bonds