Биология - Пошаговая помощь с домашним заданием по биологии - 151

zymes undergo a decrease in catalytic efficiency in the presence of excess gain this efficiency once temperature returns to normal: this suggests that in es not disrupt which of the aspects of enzyme structure? ptide bonds an der Waal's forces ydrophobic interactions ydrogen bonds cal conditions can affect the specificity of an enzyme for its substrate, and

Variant 2 a competitive inhibitor? mass as the substrate. e similar to the substrate. he products as the substrate. of an enzyme E , which catalyzes a reaction X. is partially denatured: which of the tities associate d with X is most likely to be affected by the partial denaturation of the native form of E? onstant k_(b) tion Delta H

9. Acet lcholine (ACh) is an important signaling molecule in the nervous system down by the enzyme acetylcho linesteras e (AChE)) in a reaction known as ACh of the following best the effec t AChE has on the hydrolysis of ACh? A . AChE increases the activation energy of ACh hydrolysis ,increasing the rate o B.. AChE increases the activation energy of ACh hydrolysis , decreasing the rate C . AChE decreases the activation energy of ACh hydrolysi s, increasin g the rate c D . AChE decreases the activation energy of ACh hydrolysis decreasing the rate 10.A functional enzyme together with its cofactor is called: A . Holoenzyme B Apoenzyme C . Coenzyme D Prostheric enzyme 11. With regards to the Michaelis -Menten equation a molecule that has the effect Vmax of a reaction upon binding to an enzy me would be called what? A Activator B . Uncompetitiv inhibitor C . Non-competitiv e inhibitor D.. Competitive inhibitor 12 . Which statemen t is true of enzymes? A . Enzymes work independent of substrate concentration. B. The activity of an enzyme might change as pH changes. C . Changes in temperatur e do not affect enzymes. D.. Enzymes catalyze chemica reactions by increasing the activation energy. 13. The active site model (also called the lock and key model) of enzyme-substrat from the induced fit model in which of the following ways? . The induced fit mode holds that the shape of the active site is altered during t substrate binding . The induced fit model holds that the shape of the substrate is irrelevant to enz binding . The induced fit model holds that the shape of the active site is permanently al binding . The induced fit model holds that enzyme.-substrate binding does not take plac active site . What is true of an uncompetitive inhibitor? It binds only to the formed between the enzyme and the substrate It reduces the activity of the enzyme and binds equally well to the enzyme wh already bound the substrate It forms the same products as the substrate. It binds to the active site of the enzyme. It binds with the enzyme in a place other than the active site of the enzyme.

14. A functional enzyme together with its cofactors is called: A Holoenzyme B - Apoenzyme C. Coenzyme D Prostheric enzyme 3 15. With regards to the Michaelis-Menten equation, a molecule that has the effect of increasing the Vmax of a reaction upor binding to an enzyme would be called what? A. Activator B. Uncompetitive inhibitor C. Non-competitive inhibitor D inhibitor 16. Which statement is true of enzymes? A. Enzymes work independent of substrate concentration. B. The activity of an enzyme might change as pH changes. C. Changes in temperature do not affect enzymes. D. Enzymes catalyze chemical reactions by increasing the activation energy. 17. What is true of an uncompetitive inhibitor? A. It binds only to the complex formed between the enzyme and the substrate B. It reduces the activity of the enzyme and binds equally well to the enzyme whether or not it has already bound the substrate C. It forms the same products as the substrate. D. It binds to the active site of the enzyme. 18. What is true of a competitive inhibitor? A. It has a structure similar to the substrate. B. It has the same mass as the substrate. C. It forms the same products as the substrate. D. It binds with the enzyme in a place other than the active site of the enzyme. 19. How would a fever most likely affect the activity of enzymes in human body? A. It would cause the enzyme to adapt to the new temperature. B. It could slow or stop enzyme function. C. It will change the amino acid sequence of the enzyme. D. It would increase enzyme activity. 20. What will happen with the amount of the enzyme after biochemical reaction: A. The amount of the enzyme will always reduce B. The amount of the enzyme will never reduce C. The amount of the enzyme will reduce in catabolic reactions D. The amount of the enzyme will reduce in anabolic reactions 21. Write down and explain Michaelis -Menten equation

8. Which of the following enzyme types catalyzes the formation of a single bond between two substrates? A Ligase B. Oxidoreductase C. Isomerase D. Hydrolase active site 9. Enzymes undergo n decrease in catalytic efficiency in the presence of excess temperature but can regain this efficienc y once temperature returns to normal: this suggests that temperature does not disrupt which of the following aspects of enzyme structure? A. Peptide bonds B. Van der Waal's forces C. Hydrophobic interactions D. Hydrogen bonds 10. Local conditions can affect the specificity of an enzyme for its substrate, and thus the enzymes catalytic ability: which of th alterations would most likely not affect an enzyme in this manner? A. Increased temperature B. Increased concentration of H+ C. Increased substrate concentration D. Increased concentration of salts 11. Enzymes catalyze biochemical reactions by altering which of the following quantities associated with the reaction? A. The change in Gibb's free energy Delta G B. The equilibrium constant k_(eq) C. The enthalpy of formation Delta H D. The activation energy E_(a) 12. Potassium cyanide is a poison which combines with cytochrome to prevent binding of oxygen to the enzyme without altering the Km of the reaction with respect to reduced cytochrome c .Which type of inhibition does this represent? A. Noncompetitive inhibition B. Reversible inhibition C. Competitive inhibition 13. In the first step of glycolysis hexokinase produces glucose-6-phosphate G-6-P itself can also bind to hexokinase at the active site , blocking access to ATP. This is an example of: A. Allosteric inhibition B. Feedback inhibition C. Uncompetitive inhibition

Помощь с домашним заданием по биологии