Enzymes Quiz
4 methods enzymes use to reduce activation energy.
1. Forcing substrates together (make more likely to react) 2. Orienting substrates (positioning substrates optimally for reaction) 3. inducing fit (changing shape of enzyme so that the fit improves) 4. Shutting out water (water can interfear with certain reactions)
Types of metabolic pathways
1. Linear - Straight from reactant to product 2. Cylic - Last step regenerates reactant for first step so it can keep going Both are common and complex
What is the hydrogen peroxide chemical formula?
2H2O2 --> 2H2O + O2
phosphorylation
A phosphate group transfer the transfers energy. Cells constantly run this reaction to replenish ATP reserves
ATP hydrolysis
ADT hydrolysis to ADP + a phosphate group, yeilds energy for celluslar work The reaction of releasing energy from ATP with hydrolysis is exergonic - the energy releeased from that is used to fuel annother reaction.
Our energy currency
ATP
ATP is a _______
ATP is a coenzyme. ATP carries a chemical group from one reaction to another. ATP is modified but it cycles between ADP and ATP,
phosphoylation
ATP synthesis from ADP + a phosphate group. Requires energy from other catolbolic reactions The reaction of adding a phosphate group is endergonic - it requires additional energy
Induced fit model
Active site and substrate have complementary shapes...The induced fit model means that the substrate and enzyme aren't quite perfect fits and the enzyme has to change the active site a little for the substrate to fit perfectly. This helps speed up the reaction.
Metabolism
Activities by which cells acquire and use energy as they build, breakdown or remodel organic molecules
As atoms cannot be BLANK or BLANK, energy cannot be BLANK or BLANK.
As atoms cannot be lost or destroyed, energy cannot be created or destroyed.
What would happen to a enzyme moderate reaction w/o the enyme
Bascally nothing would happenNothing would happen
Sucrase
Catalyzes the hydrolysis of sucrose.
Why do cells need controls over metabolism
Cells conserve energy and resources. They make just the right amount. Many reactions run forward and in reverse so that it makes just the right amount and not any extra
What does clean-up entail?
Clean-up will entail washing the flasks, sensor, and whatever we use to add the hydrogen peroxide. We will also need to put away materials and throw out the liver we used.
Trypsin
Continues to digest proteins in the small intestine. Requires a neutral environment.
How many trials are being conducted?
Eight trials are being conducted.
What type of reaction is it when the free energy of the products is less than the free energy of the reactants.
Exergonic
Reaction in hydrogen perozide and catalase chemical reaction demo
Hydrogen peroxide ---> Oxygen Gas + Water 2H2O2 → O2 + 2H2O
Effect of pH on enzyme activity
If solution is too acidic or basic, the Hydrogen bonds can break
How does surface area impact catalase activity?
Increased surface area would increase catalase activity because there are would more enzymes exposed to the substrate.
postive feedback loop
Increases the responce... like a chain reaction
Why are enzymes needed
Life's chemical reactions are too slow Enzymes lower activation energy, causing reactions to occur quicker
Chemical reactions are required for
Metabolism
Anabolic reaction
Monomer molecules ---> Cell Macromolecules ATP ---> ADP
14. Did lactase break down sucrose?
No
Bubbling scale
On a scale of 0 to 10, with 0 being no bubbling and 10 being a lot of bubbling, record your observation.
Feedback loop
Organims have feedback mechanisms that help maintain homeostais by allowing them to respond to changes in their internal and exernal environments
Qualitative Data..
Record any qualitative observations that you may have during the course of the lab, including any potential sources of error that impacted the data / trials.
How do cells harvest energy?
Running exergonic reactions that break bonds of organic molecules
What are the trials?
Sand Solid Liver Ground Liver Acid Liver Basic Liver Cooked Liver Salted Liver Frozen Liver
Metal ions as cofactors
Stablizes enzymes/interacts with electrons in nearby atoms. They can easly exchange and interact with electrons.
Chemical reaction of breaking down Sucrose
Substate = sucrose Enyme = sucrase Products = glucose and fructose
Reaction in hydrogen perozide and catalase chemical reaction demo: What is the substrate in this chemical reaction?
The Hydrogen Peroxide is the substrate in this chemical reaction.
lock and key model of enzymes
The Key is what is called the SUBSTRATE the part you put the key in is called the ACTIVE SITE.
What is the enzyme being studied in this activity and where is it located?
The enzyme being studied in this activity is catalase, which can be found in high quantities in the liver.
What is the overall purpose of this lab? What questions are we investigating?
The overall purpose of this lab is to understand what elements impact the function of an enzyme. We are testing to see how surface area, acidity, cooking, salinity, and freezing impact how an enzyme-moderated reaction takes place. We are asking what circumstances catalase enzymes function best and how different conditions of the enzymes affect the chemical reaction and formation of products.
Reaction in hydrogen peroxide and catalase chemical reaction demo: What is the dependent variable in this experiment?
The oxygen concentration was the dependent variable in this reaction.
What are we using for the reaction (test tubes, beakers, flasks?)
We will be using flasks.
allosteric regulation
When an enzyme's function at one site is affected by the binding of a regulatory molecule to a separate site.
Enyme-substrate complex
When the enzyme and the substrate are connected
If a reaction is profomed with an enyme and when without an enyme which reaction would have a higher Activation energy
Without
Reaction in hydrogen perozide and catalase chemical reaction demo: Why was yeast used in 2 of the trials?
Yeast was used instead of catalase in two of the reactions because it is a living organism and almost all (if not all) need to be able to break down hydrogen peroxide and have Catalase.
12. A catalyst is defined as a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. Is the enzyme lactase a catalyst? Explain why or why not.
Yes. Without Lactase the molecule Lactose would not break down at a quick enough rate. Also, the reaction of breaking down lactose does not alter the lactase enzyme which allows it to continue to break down lactose molecules.
1. Each disaccharide is made up of two ___ .
__Monosaccharides
2. When a sucrose molecule is digested, which monosaccharides are produced?
____Fructose and Glucose______________
Ea
activation energy; energy required to bing reactant ponds to their breaking point. The breaking point is the transitions state (reactions can run without additional Energy input)
example of negative feedback loop
body temperature and maintaining proper glucose levels
example of positive feedback loop
childbirth and blood clotting
organic cofactors
coenzymes Carry chemical groups/electors to other reactos and oftenin/out of organells
How do cells store energy?
endergonic reactions that build organic compounds
Free Energy
energy that is available to do work - bond energy and entropy both continbute to this - free energy of the reactants is not equal to teh free energy of the products in most reactions
Catalysis
increasing of the reaction rate by a molecule not changed by participating in the reaction. Photosynthesis absorbs the energy from light to build glucose, which contains energy for consumers.
Digestion of lactose chemical reaction
lactose = product Lactase = enzyme Product = Glucose + galactose
15. Does the same enzyme digest lactose and sucrose? _
no
What is catalase responsible for?
responsible for breaking down the toxic byproducts of cell metabolism. When cells metabolize lipids, great deals of hydrogen peroxide build up. Catalase breaks down this toxic waste product to help cells maintain homeostasis.
Catalyst
substance that speeds up the rate of a chemical reaction
Activation energy
the minimum amount of energy required to start a chemical reaction. Both exergonic and energonic rections have an activation energy
Substrate
the specific reactant that an enzyme acts on
There are four steps in the process of an enzyme working
1: An enzyme and a substrate are in the same area. The substrate is the biological molecule that the enzyme will work with. 2: The substrate bumps into the enzyme in a special area called the active site. The active site is a specially shaped area of the enzyme that fits around the substrate. The active site is the keyhole of the lock. 3: A process called catalysis happens. Catalysis is when the substrate is changed. It could be broken down or combined with another molecule to make something new. 4: The enzyme lets go. BIG IDEA - When the enzyme lets go, it returns to its original shape, ready to do another reaction. However, the substrate is no longer the same. The substrate is now called the product.
1: What does a catalyst do?
A catalyst speeds up chemical reactions by reducing the activation energy.
Alloseric regulation
Allosteric regulation helps decrease or increase an enzyme's productivity. These allosteric regulations help maintain the proper amount of reactants and products.
5: What effect does changing the temperature or pH level have on an enzyme?
An enzyme is a protein meaning that its function depends on its structure. Changing the temperate or pH level could cause an enzyme to denature and lose its function. Changing the temperature or pH can change the shape of the enzyme meaning that the enzyme can no longer do its job.
2: What macromolecule is an enzyme and what do enzymes do for living things?
An enzyme is a protein that serves as a biological catalyst in living things. Specifically designed to be a biological catalyst.
how energy flows through living things.
BioChemical reactions
In chemical reactions....
Bonds between reactants are broken or bonds are formed between reactants resulting in a new product. Atoms are not lost or destroyed, they are just rearranged. Same number of atoms on reactant side and product side.
Describe how ATP is renewable energy
Breaking down ATP releases energy, and cells constantly replace their ATP by wacking a spare phosphate opt ADP. The energy for that comes from the food we eat or make (in plants). Eneymes control the breaking and making of ATP.
Metabolic Pathways
Breaking down and building molecules requires many steps. Intermediate molecules are what are created before the end product is produced. These pathways have to be controlled or they will run continuously. can be linear or cyclic
Reaction in hydrogen perozide and catalase chemical reaction demo: What is the biological catalast in this chemical reaction?
Catalase was the biological catalyst, or enzyme, in this chemical reaction.
With all of thease reactions why oes the earth no go up in flames
Chem bonds do not break w/o imput activation evergy even in energy-releasing reactions.
ATP/ADP cycle
Cycle of using and replenishing ATP this is done by adding a phosphate group to ADP in an exergonic reaction The ADP/ATP cycle couples endergonic reactions with exergonic ones. Metabolic pathways are used to harvest energy and store it in ATP and in electors carried by reduced coenzymes
Amylase
Digestive enzyme in saliva that starts to break down starches.
Lipase
Digestive enzyme that breaks down large pieces of lipids into small lipid pieces.
Pepsin
Digestive enzyme that digests proteins into smaller peptides. Requires an acidic environment.
Feedback inhibition
End products often inhibit activity of 1 enzyme in the metabolic pathway. A change from activity decreases or stops a reaction.
What type of reaction is it when the free energy of the products is greater than the free energy of the reactants.
Endergonic
Anabolism
Endergonic; the process of building up larger molecules from smaller ones.
Catabolic reaction
Energy containing nutrients --> + energy depleted end products ADP --> ATP
Energy transfer
Energy moves through metabolic pathways. Everytime energy is transferred a certain amount of it is lost as heat. Heat is not a source of energy for living things, This is why energy needs to be replenish or the organism will die.
The ATP cycle
Energy released by catabolic reactions in the cell is used to phosphorylate ADP, regenerating ATP. Chemical potential energy stored in ATP drives most cellular work. ATP is like a rechargeable battery or a spring
Environmental factors that influsence enzymes
Environmental factors - ph, temperature, salinity inference enzyme shape and function. Each enzyme functions best in a specific range of conditions that reflect where it evolved.
Denaturation
Enzyme unfolds, losing the optimum shape for the specific substrate. The causes the eneyme to lose its active site and then it cannot perform its function.
Enzymes
Enzymes = proteins that act as biological catalysts Used to speed up chemical reactions that take place in cells/living things
how can a single lactase molecule break down many, many lactose molecules?
Enzymes are used over and over again. Once the enzyme breaks down one lactose molecule, the products are released from the active site and the active site is open for another lactose molecule.
What is the impact of salinity on catalase activity?
Enzymes need to be in a particular range of salinity to function correctly. If its surroundings have too much or too little salt, then the enzyme's efficiency will be reduced, and it could even be denatured and completely lose its function.
What type of reactions can be spontaneous?
Exergonic (very little energy is needed to run thease reactions )
Catabolism
Exergonic;Metabolic pathways that break down molecules, releasing energy.
How Enzymes Lower Activation E
Helping substrates come together - Brings together substrates, the closer they are to each other, the more likely they will react. Orienting substrates in favorable reaction positions - Molecules are always moving and their movement is random so to get them in just the right position so a bond can be formed is difficult, an enzyme helps that. Shutting out water - Water can interfere with reactions, the active site shields the reaction from water.
Virtual Enzyme Lab: Predict what would happen if you used 20 grams of substrate and explain your reasoning behind your prediction.
I do not think there would be any change in the amount of product produced if 20 grams of substrate were used because there was no change in the amount of product when the amount of substrate was doubled from 4 to 8 grams. I would guess this is because the enzymes can only bond to so many substrate molecules in a given amount of time. There are only so many enzymes. It would look the same as 4/8 grams. What is limiting them? The limiting factor is the number of enzymes. There are only so many enzymes. In that amount of time, they can only bond to so many substrates. The enzymes can only work so fast. If you leave it for longer then more product would be produced because enzymes can be reused.
Virtual Enzyme Lab: Make a prediction about what you think the reaction rate would look like at a pH of 2 and explain your reasoning behind the prediction.
I think the reaction rate would be reduced or the reaction would stop completely if the pH was changed to 2. The reaction rate has been steadily decreasing as the environment gets more acidic, so it makes sense that the rate would continue to go down if the pH were lowered to 2. There is also a possibility that a pH of 2 would denature the enzyme causing the reaction to stop completely.
Reaction in hydrogen perozide and catalase chemical reaction demo: What do you predict would happen if the water in all the trials was cold?
I would predict that the reaction would work slower (or stop completely if the enymes were denatured)if the water in all of the trials was cooled because generally enzymes function better when it is warmer (up to a certain point) and stop functioning when they get too cold. Also reducing the heat reduces the entropy which reduces the chance of random collisions between substrates and enzymes. You get to the peak of an a reaction faster with more heat. Reduces atomic movement
Effect of temperature on enzyme activity
If temperature is too low, the reaction will be slower If the temperature is too high, the Hydrogen bonds within the enzyme are disrupted and the enzyme changes shape.
How do you know glucose is present on a glucose test strip?
If the glucose test strip changes color from yellow to green, then glucose is present. The darker the green color, the greater the concentration of glucose present. If the test strip does not change color and stays yellow, then there is no glucose present.
Virtual Enzyme Lab: What would happen to enzyme activity if the temperature decreased? Think about molecular movement and collision rates...
If the temperature decreased then enzyme activity would be reduced. Generally, more heat means more molecular movement, leading to a higher chance of enzyme-substrate collisions. If there are fewer enzyme-substrate collisions then enzyme activity would be reduced along with the rate of the reaction. If the temperature decreased too much, then the enzymes would denature, and the reaction would stop completely. Reduce the frequency of the substrate interacting with the enzymes because the molecular activity is reduced.
Virtual Enzyme Lab: What would happen to enzyme activity if the temperature increased? Think about molecular movement, collision rates, and if the temperature gets too high...
If the temperature increased, the enzyme activity would increase up to a certain point. Generally, more heat means more molecular movement, which means a higher chance of enzyme-substrate collisions. If there are more enzyme-substrate collisions, then enzyme activity increased along with the rate of the reaction. However, if the temperature increases too much, then the enzymes would denature, and the reaction would stop completely.
6: Why do you think it is good that when the product(s) are released from the active site the enzyme is available for another chemical reaction?
It is good that when the products are relaced from the active site the enzyme is available for another chemical reaction because the body will not need to spend energy, time, and resources on making a new enzyme. This means that the body can complete chemical reactions faster and function more efficiently. Billions of reactions are occurring in you at any given time - it would be crazy inefficient if every reaction needed a new enzyme You will eventually need to make new enzymes but they can perform many, many reactions in their life time.
What is the impact of low temperature on catalase activity?
Low temperature would cause the catalase enzyme to function less efficiently or completely lose its function. As a general matter, when the temperature is reduced, so is a molecular movement, which makes the chance of substrate-enzyme collisions less likely, reducing the reaction's speed. If the temperature got too low, then catalase could denature, causing the reaction to stop completely.
Negative Feedback Loop
Maintains equal balance
Cellular structure of an enzyme
Make of Amino Acids (R group which controls function, Amine group, and carboxyl group). Primary, secondary, tertiary and quatrernary structure (describe)
Tyrosinase mutation in Siamese cats.
Mutation of Tyrosinase is very sensitive to temperature. too warm the enzyme is denatured. Ideal temperature 37 degrees C, 98F. Tyrosinase main function is to produce melanin, melanin is the pigment that determines hair and skin color. The mutated tyrosinase in Siamese cats is affected by temperature it doesn't melanin at warm temps. so then white fur. Where it does work, darker fur. This connection to temperature is a DNA mutation in Siamese cats.
Chemical reaction
Process that changes one set of chemicals into another set of chemicals
2 H2O2 → O2 + 2 H2O What are the reactants and the products
Reactants = Hydrogen Peroxide Products = oxygen gas and water
How to enzymes help bring reactions to the transition state?
Reducing the activation energy
What Influences enzyme activity?
Regulatory molecules and ions
Cofactors can be ________ or ___________
Separate molecules or tightly bonded to enzymes
heme
Small organic compound with iron atom at center. Catalase neutralizes hydrogen peroxide by holding it close to a heme. antioxidant - interfear with oxidation and reduce then damage caused by it (essental to health)
4: Explain why some enzymes change the shape of their active site and what benefit does this give to the chemical reaction?
Some enzymes slightly change the shape of their active site in order to reduce the activation energy. Induced fit theory - the "tighter fit" reduces the activation energy
16. Which part of an enzyme do you think is responsible for this enzyme specificity? Explain your reasoning.
The active site is responsible for the specificity of enzymes. The active site must match shape of the substrate.
What is the impact of high temperature on catalase activity?
The high temperature would cause the catalase enzyme to function more efficiently up to a certain point. When the temperature is raised, so is molecular movement which increases the chance of substrate-enzyme collisions, increasing the speed of a reaction. However, if the temperature gets too high, then the enzymes will denature, and the reaction will come to a complete stop.
What is the impact of low pH on catalase activity?
The optimal pH for catalase to function at is 7, meaning that at any pH below that, the catalase enzyme's efficacy will be reduced. If the pH gets too low, then the enzyme will be denatured and stop working entirely.
What is the impact of high pH (alkalinity) on catalase activity?
The optimal pH for catalase to function is 7, meaning that the catalase enzyme's efficacy will be reduced at any pH above that. If it gets too alkaline, then the enzyme will denature and stop working altogether.
Metabolic pathway
The series of enzyme moderated reactions that perform metabolism
Reaction in hydrogen peroxide and catalase chemical reaction demo: What is the independent variable in this experiment?
The time was the independent variable in this experiment
feedback inhibition of enzyme pathway
These feedback loops are important so that the right amount of certain molecules is produced and that there isn't an excess. The product tryptophan will be used as an allosteric inhibitor in the first enzyme that started the pathway.
How do Regulatory molecules and ions influence enzyme activity
They can help or hind enzymes - some bond directly to the active site - others bond to a region outside of the active site (allosteric regulation) Regulating one enzyme can impact the whole metabolic pathway.
Reaction in hydrogen perozide and catalase chemical reaction demo: Out of the 5 trials which trial(s), is/were the control group(s)?
Trial 1: Water and Catalase Trial 2: Water and Yeast Trial 3: Water and Hydrogen Peroxide
Reaction in hydrogen peroxide and catalase chemical reaction demo: Out of the 5 trials which trial(s), is/were the experimental group(s)?
Trial 4: Water & Yeast & Hydrogen Peroxide Trial 5: Water & Catalase & Hydrogen Peroxide
How many data points are you collecting? What are they?
We are collecting data on the amount of bubbling produced during the reaction, how oxygen gas is produced as well as recording qualitative data such as observations during the reaction.
What chemical reaction are we investigating in this lab? What are the reactants and products?
We are investigating the chemical reaction that takes place when the enzyme catalase breaks down hydrogen peroxide into water and oxygen. The reactant is hydrogen peroxide and the products are water and oxygen.
Are we using digital thermometers or oxygen gas probes?
We will be using oxygen sensor probes to determine the consentration of oxygen gas produced during the reaction.
How many lines do we end up with on our graph?
We will end up with eight lines on our graph because eight trials are being conducted.
How long do we let each trial run for?
We will let each trial run for three minutes adding the hydrogen peroxide 10 seconds into the experiment.
Virtual Enzyme Lab: Think about the relationship between the amount of substrate and the amount of product. What happens when you increase the amount of substrate?
When you increase the amount of substrate, the amount of product increases up to a certain point. The highest amount of substrate you can use in the reaction and still see an effect in the amount of product produced appears to be 4 grams as shown by the graph above.
Will you be testing for every variable listed in the "key questions to consider" heading?
Yes, we will be testing for all the variables listed in the "key question to consider" heading. These include surface area, temperature, pH, and salinity.
Active site
a crevice on the enzyme, it provides a site where the substrates (reactants) can bond to the enzyme. Active site provides an environment conducive to the chemical reaction to happen, and lessens the amount of activation energy needed.
What does every chemical bond have?
a given amount of energy (the amount of energy required to break the bond)
ATP
a special coenzyme.... cofactor in many reactions - 3 phosphate groups is transported/from a nucleotide... energy is transferred with it - it can receive energy from exergonic reactions Used to drive endergonic reactions that cells run
example of exergonic reaction
aerobic respiration During cellular respiration (aerobic respiration), the mitochondria will break down glucose in three processes and harness the energy between the carbon atoms.
Cofactors
enzyme helpers
Can an enzyme break up a substrate it was not designed to bond to
no
example of endergonic reaction
photosynthesis Photosynthesis absorbs the energy from light to build glucose, which contains energy for consumers.
active site
place in an enzyme where substrate binds and reaction is performed. Reason each enzyme acts in a specific way on a specific substance. Formed by enzyme polypeptide chains
Why does metabolism require enzymes
they make a profound difference in speed
% Oxygen Gas vs. Time Graph: x-axis: y-axis:
x-axis: Time y-axis: % Oxygen Gas If you see an increase in oxygen gas production, you know a chemical reaction occurred. If there is no change in oxygen gas production, then you know a reaction did NOT occur. However, the more active the enzyme, the greater oxygen gas production you should see.
