Karteikarten
Enzymes 1
Karten in diesem Stapel (36)
- 1What % of total protein content is predicted to be enzymes?25%
- 2by what factors can enzymes speed up naturally occurring reactions?carbonic anhydrase=10^7
Phosphoglucomutase=10^12
succinyl-CoA transferase= 10^13
Urease=10^14 - 3At what conditions do enzymes work in?-Perform their functions under very mild conditions
-Temp=37 degrees celcius
-pH=7.4
-Pressure= normal atmospheric pressure(1bar or 14.5psi) - 4At what conditions do industrial catalysts work at?- Require extreme conditions to perform their functions, e.g ammonia
- Temp=477 degrees celcius
- Pressure= 200bar or 2900psi(pressure at 2000m under water) - 5What happens to enzymes at extreme conditions?- Extremophile microorganisms have evolved to flourish at these extreme conditions
- These enzymes are also made to work in these extreme conditions - 6What are the general properties of enzymes?1) Higher reaction rates
2) Milder reaction conditions compared to chemical catalysis
3) Greater reaction specificity compared to chemical catalysis
4) Capacity for regulation - 7Who decided on the naming of the the enzymes?- It was decided by the international union of biochemistry and molecular biology(IUBMB) that the naming of enzymes have a clear rationale
- 8What are enzymes now classified according to?- According to the nature of chemical reactions that catalyse and are assigned an Enzyme Commission(EC) number
- 9EC= 1 Classification=? B.P=?- Oxidoreductases
- Act on many chemical groupings to add or remove hydrogen atoms - 10EC=2 classification=? B.P=?Transferases
-Transfer functional groups such as methyl or glycosyl between donor and acceptor molecules. Kinases are specialised transferases that regulate metabolism by transferring phosphate from ATP to other molecules - 11EC= 3 Classification=? B.P=?Hydrolases
- Add water across a bonds, hydrolysing it - 12EC=4 Classification=? B.P=?Lyases
- Add water, ammonia or carbon dioxide across double bonds, or remove these elements to produce double bonds - 13EC= 5 Classifiction=? B.P= ?Isomerases
Carry out many kinds of isomerization - 14EC=6 Classification=? B.P=?Ligases
Catalyse reactions in which 2 chemical groups are joined with the use of energy from ATP - 15How are the major classes of enzymes subdivided?- Class
- Subclass
- Sub-subclass
- Sub-sub-subclass - 16What is the lock and key hypothesis?- The active site has a specific shape to the substrate
- When the substrate comes in close enough vicinity to the active site, amino acids that line the active site attract the substrate closer - 17What is the induced fit theory/- The active site is not rigid but is flexible
- Upon tentative binding between substrate and enzyme, the conformation changes somewhat to accommodate a tighter interaction between the enzyme and substrate - 18How many different types of enzyme specificity are ther?4
- 19What is absolute specificity?- the enzyme is specific for one substrate
- 20What is relative specifity?- The enzyme acts on a group of closely related substrates
- 21What is group specifity?- Most proteolytic enzymes show group specificity
- 22What is stereospecificity?- Human enzymes are specific for L-amino acids and D-monosaccharides
- 23When do enzymes increase the rate of reaction?- Enzymes increase rate of reaction whether or not a reaction takes place or not
- 24Whether a reaction takes place depends on what?-Free energy change
- 25What is entropy a measure of?- Randomness
- The higher the randomness, the higher the entropy - 26Why is energy required?- To maintain order
- 27What do enzymes not determine?- Enzymes do not determine the equilibrium of a reaction but determine how quickly it reaches the equilibrium
- 28In a reaction, what is more stable?- The products are more stable than the reactants
- 29What is the 1st stage of a reaction?- Existing bonds are broken and new ones are formed
- This usually requires the distortion of an existing bond to create a transition state - 30What is the 2nd stage of a reaction?- The transition state of the reactants contain the highest free energy compared to the original reactants and end products
- The difference in the free energy between the transition state and the reactants in their original state is called the activation energy - 31Why is id difficult to hold the molecule in the transition state?- It requires energy
- 32What is the equation?A-B + C ---> [A---B---C]---> A + B-C
- 33What is the 1st stage of how enzymes speed up reactions?- Substrate binds 'weakly' into the enzyme's active site
- 34What is the 2nd stage of how enzymes work?- The enzymes distorts the substrate to facilitate its tighter binding
- The substrate is no longer in its original state but is now in the transition state
- The enzyme binds more tightly to the transitional state of the substrate and also makes the desired reaction easier - 35What is the 3rd stage of how enzymes work?- Once the product is formed, the enzymes has less affinity to bind the products and the products are released
- 36—
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- Highers Biochemistry Karteikarten am Enzymes 1 , erstellt von Shalini Selvaratnam am 23/12/2020.
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- Shalini Selvaratnam
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