| What are polysaccharides used for? | Energy storage, such as starch in plants and glycogen in animals, or structured components like cellulose in plants |
| What is a macromolecule? | Large molecules that often have complex structures |
| What is a notable character of macromolecules? | Many are polymers |
| What does polymer mean? | A long, chain like molecule composed of many smaller molecules (monomers) linked together |
| What is a monomer? | Small molecule that when linked up together, form polymers. |
| What're the 4 major categories of molecules associated with life? | Carbohydrates
Lipids
Proteins
Nucleic Acids |
| What are carbohydrates made of, and what ratio are they in? | Carbon, hydrogen, and oxygen, they're in a 1:2:1 ratio (ex. Glucose) |
| What are carbohydrates made up of? | Made up of simple sugar monomers |
| What are simple sugar monomers called? | Monosaccharides |
| What are 3-4 characteristics of a monosaccharide that makes it easy to identify? | All single ringed. At-least : 2 Hydroxyl groups, an aldehyde, or ketone |
| Where is glucose found? | In fruits and candies |
| Where is fructose found? | In tree fruits |
| Where is galactose found in? | Dairy |
| What're the 2 minimal requirements that carbohydrates must have? | 2 hydroxyls minimum
Ketone and aldehyde |
| What is a disaccharide? | 2 simple sugar units linked together |
| What're 2 examples of a disaccaride? | Sucrose and lactose
Sucrose is found in table sugar and lactose in dairy |
| What is an oligosaccharide? | 3-10 sugar links together |
| How are sugar links in oligosaccharide linked together? | They're linked by covalent bondsThe hydroxyl groups on adjacent sugars react to produce a molecule of water (dehydration synthesis) and link sugars through a shared sugar |
| What is condensation/dehydration? | Builds larger molecules from smaller units while producing water |
| What are polysaccharides? | Complex carbs that provide vitamins, minerals, and fibers |
| When are polysaccharides formed? | Formed when dozens, hundreds, thousands of simple sugar units are linked |
| What are mono, di, and oligosaccharides used for in the human body? | Quick energy |
| What are polysaccharides used for? | Energy storage, such as starch in plants and glycogen in animals, or structured components like cellulose in plants |
| Relate the chemical structure of carbohydrates to their physical properties and uses | Carbohydrates are hydrocarbons that are dependent on their length, structure, and functional groups to determine their solubility. They are useful sources of structural materials and energy for living organisms |
| Why are most polysaccharides insoluble in water? | Their large size makes it hard for them to dissolve |
| What are lipids? | Class of greasy, oily or waxy compounds that are non-polar and water insoluble |
| What are the 3 elements that lipids are composed of? | CHO |
| What is the function of lipids? | Energy storage, insulation, structural components, absorption of vitamins and minerals, and hormones |
| What are the 2 major classes of lipids? | Fatty acid and fatty non-acid |
| What is the backbone of fatty acids made up of? | Carbon atoms (Up to 36) which ends in a carboxyl group (that's how you identify it) |
| What are the 2 types of fatty acids? | Saturated and unsatured |
| What are saturated fats? | Fatty acids that contain only single bonded carbons (e.g stearic acid) |
| What is the reason that saturated fats clog arteries? | Due to their linear structure, they stack ontop of one another easily and become solids are room temperature and thus clog veins |
| What are unsaturated fats? | fatty acids that have one or more double bonded carbons (e.g oleic acid) and become liquid at room temperature |
| What are phospholipids, what out of the 2 major groups of fats do they have attached? | They are a fat, consisting of a phosphate "head" (hydrophilic) and attached to 2 fatty acid "tails" (hydrophobic) |
| What is so special about phospholipids? | They are the main component of cell membranes |
| What is the structure of triglyceride, hint look at the name? | Glycerol joined to 3 fatty acid "tails" |
| How does triglyceride form? | A condensation reaction occurs between hydroxyl groups on the glycerol and the carboxyl group on each fatty acid. |
| What is the link for carbohydrates called? | Covalent |
| What are the links for hydroxide and hydroxyl (lipids?) called? | Ester linkage |
| How can you make a series of saturated fatty acid tails become unsaturated? | If one fatty acid tail is unsaturated, the entire molecule is unsaturated even if it has more saturated tails |
| What is special about triglyceride compared to carbohydrates? | Triglyceride contains twice the stored energy as the same mass of carbohydrates |
| What are waxes? | Long fatty acid chains linked to alcohols or carbon rings, hydrophobic, extremely non polar and soft solids |
| What is the function of waxes? | To be water resistant and as protection
ex. Wax coat on fruits, leaves, stems (cutin), grass, and beeswax |
| What are lipids without fatty acids called? | Steroids |
| How are steroids formed? | Lack fatty acids, have 4 fused hydrocarbon rings |
| Why is cholesterol important? | Important structural component of cell membranes and functional groups |
| What are some other steroids? | Sex hormones (testerone, estrogen, and progesterone) |
| What is the shape of a steroid? | Steroid shape roughly |
| Compare the polarity of carbohydrates and lipids, how does their polarity relate to their physical properities? | Carbohydrates' polarity enable them to be soluble, and dissolve in water.
Lipids are non-polar, making them insoluble in water, and thus very useful as cell membranes and water proofing molecules |
| Distinguish between fatty acids and a fat | Fatty acids consist of a carboxyl group at one end (giving it its acidic property) and a long hydrocarbon chain
A fat is a lipid that is made up of 2 types of molecules, fatty acid, and glycerol. 3 fatty acid chains attach to the glycerol molecule |
| What happens to the acidic properties of a fatty acid when a fat is formed? | Acidic properties of fatty acids come from carboxylic acid functional groups, and this quality does not exist in fats |
| Why are steroids important, even though they tend to have a bad reputation? | Cholesterol is a steroid that is an important component of plasma membranes that surround animal cells.
Plants have similar things called phytosterols that form in plant cell membranes.
Cholesterol converts into a number of compounds like vitamin D.
Steroids control the development of sexual traits and sex cells
TLDR: Important in plasma membranes, converts into compounds like vitamin D, controls development of sexual traits and sex cells. |
| Why are cutins important for life? Where are they found? | Found in wax, and conserve water/act as a barrier to infections and diseases for some plants |
| What are the basic building blocks of proteins? | Amino acids |
| What are amino acids composed of? | Central carbon atom linked to an amino group, carboxyl group, hydrogen atom, and R group |
| What is another name for R group? | Side chain or variable group of atoms |
| How many different amino acids are there? | 20 |
| What is the significance of an R group? | Makes one amino acid different from one another |
| How do amino acids form a protein? | By linking together |
| What are the structure and function(s) of proteins determined by? | Determined by the sequence of amino acids |
| How are amino acids joined together? | Joined together through condensation reactions between a carboxyl group and amino group |
| What is a peptide bond? | Reaction between carboxyl group and amino group |
| What are the functions of proteins? | Structural components (muscle tissue and collagen in skin)
Messenger molecule (hormones)
Anti-gens (used in immune response)
Carrier molecules (hemoglobin carries O2)
Transportation of materials (channels in cell membranes)
Enzymes (catalyze biochemical reactions)
SMACTE |
| What do structural proteins generally form? | Strands or sheets, others have globular shape |
| How many levels of structure do globular proteins have? | Primary (1), Secondary (2), tertiary (3), quaternary (4) |
| What is the structure of the primary structure? | Sequence of amino acids in a polypeptide chain |
| How is secondary structure caused? | Caused by hydrogen bonding between adjacent amino acids, and may cause polypeptide chain to develop a helical or pleated shape |
| What might secondary structure cause (in regards to a polypeptide chain)? | May cause polypeptide chain to develop a helical or pleated shape |
| What happens to the polypeptide chain because of tertiary structures? | Results in further folding of polypeptide chain to cause interactions of R-groups |
| What causes an quaternary structure to form? | Caused by interaction of 2 or more polypeptide globules
overall result is a protein with a very specific 3 dimensional shape with unique surfaces and pockets |
| What are all other levels of protein structures besides the ones we mentioned a consequence of? | Consequence of primary structures |
| What are the structure and function of a protein determined by? | Determined by the sequence of amino acids |
| What are the basic building blocks of nucleic acids? | Nucleotides |
| What do nucleic acids contain? | 5 Carbon sugar, a phosphate group, and a nitrogenous base |
| What are the functions of nucleic acids? | -Biochemical energy carriers (ATP, NADH, and FADH2)
-Encoding genetic information (DNA, RNA, mtDNA) |
| What is an example of a nucleic acid? | DNA is an example of nucleic acid |
| What is DNA made of? | DNA is a polymer of nucleotides, and contains the sugar deoxyribose, a phosphate group, and one of 4 nitrogen bases |
| What are the 4 nitrogen bases? | -Guanine (G)
-Adenine (A)
-Cytosine (C)
-Thymine (T) |
| What is the structure of Adenine and Guanine? | Double ringed structure (purines) |
| What is the structure of cytosine and thymine? | A single ring (pyrimidines) |
| What is a purine(s)? | Double ringed structure |
| What are pyrimidine(s)? | Single ringed structure |
| What is the normal shape of DNA? | Double-stranded and twisted into a helix |
| How does DNA get it's double stranded and twisted helix shape? | By the double rings attaching to a single ring using hydrogen bonds |
| What is the sequence of bases made of? | Genetic code (Ie ATGAC) |
| What is another example of nucleic acids? | RNA which is a polymer of nucleotides |
| What are RNA made up of? | Sugar ribose, a phosphate group, and one of 4 nitrogenous bases: Guanine(G) Adenine (A) Cytosine (C) Thymine is replaced by uracil (U) |
| What nitrogenous base is found in DNA or RNA and not found in the other? | Thymine in DNA only
Uracil in RNA only |
| What is the structure of RNA? | Normally single stranded |
| What are the 3 types of RNA involved in protein synthesis? | Messenger (mRNA), transfer (tRNA), and ribosomal (rRNA) |
| What is the role of the sugar and phosphate groups in the structure of nucleic acids? | Phosphate groups bridge one nucleotide to another between the 5 carbon ring sugar and the 3 carbon ring sugar. Forming the backbone of nucleic acid chain |
| explain the similarities and differences between DNA and RNA? | Similarities:
Consist of chains of nucleotides, and have a similar compound make up, 3/4 same nitrogenous bases
Differences:
DNA is almost always found in a long helix shape
RNA takes a variety of forms
Each nucleotide in a DNA chain contains a deoxyribose, a phosphate group, and one of 4 bases: ATGC
Each nucleotide in an RNA chain contains a ribose, a phosphate and one of the 4 bases: AUGC
DNA stores the hereditary information that is responsible for inheriting traits in eukaryotes and prokaryotes and in viruses
RNA is the hereditary molecule of some viruses |
| How does the function of nucleic acids differ from that of other types of macromolecules? | Nucleic acids serve many functions, and are an important molecule, necessary for the production of protein in cells.
Carries genetic information and has assembly instructions for all proteins in living organisms
TLDR
it is necessary molecule for proteins production in cells
carries genetic info
has assembly instructions for all proteins in living organisms |
| What is an example of a monosaccharide? | Glucose, fructose, galactose, ribose, deoxyribose |
| What are the subunits of monosaccharides? | None |
| What are the functional groups of monosaccharides? | Hydroxyl and carbonyl |
| Are monosaccharides polar or non polar? | Polar |
| What are examples of dissacharides? | Maltose, lactose, sucrose |
| What are the subunits of disaccharides? | Glucose |
| What are the functional groups of disaccharides? | Hydroxyl and carbonyl |
| Are disaccharides polar or non polar? | Polar |
| What are examples of polysaccharides? | Starch and cellulose |
| What are the subunits of polysaccharides? | Glucose |
| What are the functional groups of polysaccharides? | Hydroxyl and carbonyl |
| Are polysaccharides polar or non polar? | Less polar |
| What are examples of triglycerides? | Olive oil, margarine |
| What are subunits of triglycerides? | Glycerol, fatty acids |
| What are the functional groups of triglycerides? | Hydroxyl, carbonyl |
| Are triglycerides polar or non polar? | Non polar |
| What are examples of phospholipids? | Cell membrane(s) |
| What are the subunits of phospholipids? | Glycerol, fatty acids, and phosphate |
| What are the functional groups of phospholipids? | Hydroxyl, carbonyl, and phosphate |
| Are phospholipids polar or non polar? | Polar end, and non polar end |
| What are examples of steroids? | Cholesterol, testosterone, estrogen, progesterone |
| What are the subunits of steroids? | Carbon rings |
| What are the functional groups of steroids? | Hydroxyl and carbonyl |
| Are steroids polar or non polar? | Polar end and non polar end |
| What are examples of waxes? | Cutin |
| What are the subunits of waxes? | Fatty acids |
| What are the functional groups of waxes? | Alcohol/carbon rings |
| Are waxes polar or non polar? | Non polar |
| What are examples of proteins? | Hemoglobin, enzymes |
| What are the subunits of proteins? | Amino acids |
| What are the functional groups of proteins? | Hydroxyl, amine, carbonyl |
| Are proteins polar or non polar? | Polar, and non polar |
| What are examples of nucleic acids? | DNA and RNA |
| What are the subunits of nucleic acids? | Nucleotides (pentose, phosphate, base) |
| Are nucleic acids polar or non polar? | Polar |
| What are catabolic reactions? | A complex substance being broken down into something less complex
ex. combustion of gasoline (octane)
Octane + oxygen -> carbon dioxide + water + heat
This reaction produces energy |
| What are anabolic reactions? | A complex substance is built from something less complex
ex. production of sugar in photosynthesis
carbon dioxide + water -> glucose + oxygen |
| What does metabolism mean? | Sum of all carbonic and anabolic reactions in an organisms |
| What laws do all the reactions in the universe follow? | Laws of thermodynamics |
| What does the first law of thermodynamics state? | The total amount of energy in the universe is constant, cannot be created or destroyed, can be only converted from one form to another |
| What does the second law of thermodynamics say? | Energy in the universe is spontaneously flowing from higher to lower energy contents.
meaning the universe is becoming more disordered (entropy is increasing), things will break down but not be put together into complex things or structures more.
this change happens because of catabolic and anabolic processes |
| Example of a system being ordered (2nd law) | mason building a brick wall, starting with a pile of disorganized bricks and ended with an organized wall: entropy decrease
local increase in the order of the wall is at the expense of more/increase of disorder of surroundings
->muscular energy expended
-> glucose broken down into simpler molecules and heat
-> net result, is overall increase is entropy |
| Explain how organisms can grow and create internal order without violating the second law of thermodynamics? | Organisms can grow and create internal order by capture and utilizing energy from their surroundings, like sunlight, thus increase their local order while contributing to an overall increase in entropy with the second law of thermodynamics |
| Is the releasing of light by a firefly endergonic or exergonic? Explain how such a process abides by the first and second laws of thermodynamics? | First law states energy can only be transferred and thus chemical energy is becoming light energy
Second law states that in the conversion of energy, the total entropy/disorderness of a closed system increases over time, this is true as the firefly must acquire water and food using muscle energy and afterwards has a chemical reaction, showing that overall more disorder must occur for light to be made
also exergonic energy since its being released into the environment |
| Describe the first and second laws of thermodynamics? | First law states in a closed system energy can only be transferred, not created or destroyed. Your input will always equal your output.
Second law states that in a closed system, things will "decay" or become disorderly, and to fix things or make them ordered into something requires energy. |
| Explain why some people might mistakenly think that living things do not obey the second law. | Organisms are very organized internally, however to use energy to create internal organization whilst contributing to the overall entropy of the universe by processes or activities that involve energy transformations and release of heat or just movement |
| Why is metabolism important? | All processes of life require energy (growth, reproduction, etc) |
| What is energy? | Ability to do work |
| What must organisms do in order to function? | Capture, store, and use energy to function |
| What are metabolic pathways? | Reactions that transform matter and energy in our cells in a step by step sequence |
| What is a spontaneous reaction? | A reaction that will continue to completion without further energy input once initiated, ex is oxidation of glucose |
| What is a non-spontaneous reaction? | A reaction that can only continue as long as it receives a continual energy input, ex electrolysis of water to break water into oxygen and hydrogen gas |
| How does one determine what is spontaneous or not? | If the reaction is exothermic, giving off heat, occur spontaneously |
| What are 1 factor that tells us something is spontaneous? | Enthalpy (H) |
| What is enthalpy? | Total value of energy (kinetic and potential) of a system (decreases in H tend toward spontaneity, else wise it is non-spontaneous) |
| What is important about enthalpy? | The change in enthalpy is important, if the change is positive (triangle H) then the reaction is endothermic, if the enthalpy is negative, then the reaction is exothermic, usually spontaneous |
| A graph of exothermic reaction:
judging by this graph, why would you say it's a spontaneous reaction? | Exothermic Reaction Spontaneous reaction because the energy released in a bond formation is more significant than the energy absorbed by reactants And because there is entropy in the net energy between reactants and products |
| A graph of an endothermic reaction:
judging by this graph, what makes you say it's a non-spontaneous reaction? | Endothermic Graph Non-spontaneous reaction because more energy is absorbed in the reactants than released during bond formation, total entropy (energy in bonds) is positive, so it absorbed more energy/heat, and therefore, endothermic, and non spontaneous |
| What is enthalpy (H)? | Total value of energy of a system
decreases in H tend towards spontaneity |
| What is entropy (S)? | A measure of randomness of a system
Increase in S tend towards spontaneity |
| What is temperature in reference to spontaneity? | A measure of molecular motion
Increase in T tends toward spontaneity |
| What is gibb's free energy (G)? | Energy in a system that can do useful work
ex. before combustion, free energy in gasoline is higher than in products of combustion
Gasoline can do more useful work than carbon dioxide and water |
| How can spontaneity be determined mathematically? | With gibb's free energy equation Basically the change in free energy is net energy gain or loss |
| What is the ruling to determine if something is spontaneous or not using gibb? | If the difference in gibb's is positive, reaction is non-spontaneous
If the difference in gibb's is negative, then it is spontaneous |
| What is biochemical couplying? | Non spontaneous reactions require continual input of energy which is metabolically expensive
To conserve energy, spontaneous reactions are used to drive non-spontaneous reactions |
| Where does biochemical coupling of reactions occur? | On the surface of enzymes |
| Explain the relationship between energy and work | The relationship between energy and work is that energy is the ability to do work.
Work is done when an object is moved by using energy. |
| Explain the relationship between potential energy and kinetic energy | The relationship between potential energy and kinetic energy is that potential energy is energy associated with position or structure of an object and can be converted into kinetic energy—the energy associated with motion. |
| Explain the relationship between free energy and spontaneous changes | The relationship between free energy and spontaneous changes is that free energy is energy available to do work and spontaneous changes result in a reduction of free energy in the system. |
| Describe the relationship between bond energy and
energy changes that occur during a chemical reaction. | Bond energy represents the energy required to break a bond or the energy released when a bond forms.
Energy changes in a chemical reaction are a result of the difference in potential energy between the products and reactants.
In a reaction, energy is absorbed as bonds in the reactants break and released as new bonds form in the products, leading to the overall energy change of the reaction. |
| If the activation energy of a reaction is 1250 kJ/mol,
and the energy released by the formation of products
in the reaction is 1386 kJ/mol, what type of reaction
has taken place? | answer |
| In your own words, describe the difference between
anabolic and catabolic pathways. | The difference between anabolic and catabolic pathways is the change in free energy as a result of the reaction.
An anabolic pathway is a process in which complex molecules are built from simpler ones, requiring free energy.
A catabolic pathway is a process in which large complex molecules are broken down into simpler ones, releasing free energy. |
| Which of the following processes are spontaneous? Give
an example of each spontaneous process.
(a) an exothermic process that increases entropy in
a setting with a low temperature
(b) an exothermic process that decreases entropy in
a setting with a high temperature
(c) an endothermic process that increases entropy
in a setting with a high temperature
(d) an endothermic process that decreases entropy
in a setting with a low temperature | a) This can be spontaneous. An example of a spontaneous exothermic process that increases entropy in a setting with a low temperature would be the combustion of wood in the winter.
b) Exothermic process that decreases entropy in a setting with a high temperature are not generally spontaneous.
(c) This can be spontaneous. An example of an endothermic
reaction that results in an increase in entropy in a setting with a high temperature is evaporating water on a hot day. The water releases the trapped thermal energy as a result of a phase change,
which decreases the entropy of the system.
(d) There are no endothermic processes that decrease entropy at low temperatures. These reactions are nonspontaneous. |
| What are enzymes? | Enzymes are protein catalysts |
| What do protein catalysts do? | They speed up the rate of specific reaction by lowering the activation energy required to kickstart the reaction
Activation energy = (Ea) |
| Make a graph showing a reactant without an enzymes graph, then with an enzyme, label everything | Graph answer |
| Based on this graph, determine whether this is a spontaneous or non spontaneous reaction | -> gibb's free energy is negative and thus spontaneous
-> gibb's energy is the net difference
-> it is evident that more energy is released than absorbed, therefore it is exothermic, making it spontaneous |
| What do enzymes do? Are they apart of the reaction? | Generally just lower the activation energy required, and are not part of the reaction |
| Does gibb's free energy change with enzymes? | No, it does not change, but the reaction just happens faster |
| What happens to reactants when there is enzymes present? | They convert into products faster |
| Do enzymes work for a short amount of time? | Enzymes are not consumed in reaction, continue to work indefinitely |
| What is something specific that enzymes have? | 3 dimensional structure |
| How do enzymes work? What is special about their structure that lets them do their job? | Enzymes have precisely shaped active sites that are specific to a substrate that they work on |
| What is a limitation of enzymes ? | They can only catalyze a single specific reaction |
| What makes enzymes different from other catalysts? | They are delicate organic molecules, a very high temperature or change in pH can alter the 3D structure of enzymes, causing denaturation |
| What is denaturation? | Breaking something down until its useless, usually its weaker bonds are broken |
| Where do enzymes come from? | They come from DNA |
| What is the name of the earliest model of enzyme activity? | Lock and Key model |
| What does the lock and key model propose? | The lock and key model proposes an exact fit between enzymes and substrates, that when combined, the substrate convert into the product and the enzyme is left unchanged |
| How do enzymes actually react with substrates? | Substrate molecule enters active site's functional groups, its functional groups interact with the functional group of the enzymes, the enzyme changes shape to better accommodate the substrate, then the enzyme returns to its original shape |
| What is the currency accepted enzyme and substrate model called? | Induced fit model |
| Why do reactions occur? | Particles constantly moving collide with one another |
| What are the effects of substrate concentration on enzymes? | 1. As the number of substrate molecules increase so does the change of successful reaction (collision theory)2. Enzyme molecules are saturated with substrate (all enzyme molecules are occupied at any given time) |
| What're the effect of temperature on enzymes? | 1. As temperature increases so does molecular motion. this increases probability of a successful reaction (collision theory) 2. High temperature denatures the enzymes. They will no longer catalyze the reaction |
| What're the effects of pH on enzymes? | 1. Pepsin functions within pH range of 0.4-4, pepsin's optimal pH is 1.82. Trypsin functions within pH 6-10, Trypsin's optimal pH is 8.2 |
| (a) What is a substrate? What is an active site? How are they related?
(b) Why is an enzyme considered a biological catalyst? | (a) A substrate is a substance that is recognized and binds to an enzyme. An active site is the
location on an enzyme where a substrate binds and is the location of the enzymatic reaction.
(b) Enzymes are considered biological catalysts because they can be used repeatedly and are not
wasted after they catalyze a reaction. |
| Describe the induced-fit hypothesis of an enzyme-substrate interaction. | In the induced-fit hypothesis, the conformation of the enzyme changes slightly to allow for a
more precise binding of the substrate. |
| What is the functional role of a coenzyme or a cofactor in an enzyme-induced reaction? Give an example of an enzyme that requires a cofactor or a coenzyme. | Coenzymes and cofactors are required for an enzyme to properly catalyze a reaction. Pyruvate dehydrogenase requires the cofactor magnesium. |
| How does the rate of a reaction change as a result of each of the following factors? Support your answer with a graphic representation of the enzymatic rates.
(a) enzyme concentration
(b) substrate concentration
(c) temperature
(d) pH | (a) Enzyme Concentration: As enzyme concentration increases, the rate of the reaction generally increases because there are more enzymes available to catalyze the reaction. However, this relationship is subject to substrate concentration limitations and may plateau when substrate becomes the limiting factor.
(b) Substrate Concentration: Initially, as substrate concentration increases, the rate of the reaction also increases because more substrate molecules can bind to available enzyme active sites. However, at high substrate concentrations, the rate may plateau as all active sites become saturated.
(c) Temperature: Increasing temperature generally increases the rate of the reaction up to an optimal point, as higher temperatures provide more kinetic energy to the molecules, leading to more frequent collisions and successful reactions. Beyond the optimum, the rate decreases due to enzyme denaturation.
(d) pH: Enzymes have an optimal pH at which they work most efficiently. Deviating from this pH optimum in either direction (higher or lower pH) results in a decrease in the rate of the reaction because it disrupts the enzyme's active site and overall structure. |
| Describe noncompetitive enzyme inhibition. Provide an example to support your answer. | A noncompetitive inhibitor binds to the enzymes at a site other than the active site. It changes the conformation of the enzyme so that it no longer binds its normal substrate. Alanine noncompetitively inhibits pyruvate kinase forming a feedback loop preventing more alanine production |
| Why is it important for the human body to maintain a proper temperature and a proper pH at all times in regards to enzymes? | It is crucial for the human body to maintain proper temperature and pH because enzymes, which catalyze essential biochemical reactions, are highly sensitive to changes in these factors. Enzymes have specific temperature and pH optima, and deviations from these optima can denature enzymes or alter their activity, disrupting vital metabolic processes. |
| Many spontaneous reactions occur very slowly. If they can occur, why do all spontaneous reactions not take place immediately? | Even though spontaneous reactions have a tendency to occur, they may not happen immediately because they often have high activation energy barriers that must be overcome for the reaction to initiate. Additionally, the presence of reactants, proper orientation, and collision frequency all influence the rate at which spontaneous reactions proceed. |
| Draw and label a graph to illustrate the effects of an enzyme on the activation energy of an exergonic reaction and an endergonic reaction. Refer to your graphs to explain why the addition of an enzyme will not change the ∆G of either type of reaction. | The addition of an enzyme does not change the ∆G (free energy change) of either type of reaction because enzymes only facilitate the kinetics of reactions by lowering the activation energy barrier, making it easier for reactions to occur, but they do not alter the thermodynamics or the overall energy change of the reactions. ∆G remains the same before and after the addition of an enzyme. |
| What are the three mechanisms by which an enzyme lowers the activation energy of a reaction? | Enzymes can bring reactants to the transition state by one of three mechanisms:
bringing the two reactants closer together, changing the charged environment
around the substrate, or bending or distorting the substrate. |
