Enzyme Activity & Proteins Labs

Question 1

What was the effect of enzyme surface area in the enzyme lab?

Answer 1

• a taller bubble column was observed when liver was crushed
• crushing the liver exposed a greater number of ACTIVE SITES for the hydrogen peroxide to collide with
• this increases oxygen production as the enzyme (catalase) breaks down hydrogen peroxide into oxygen and water

Question 2

What was the effect of heat for the enzyme lab?

Answer 2

• when the liver was put in the hot test tube, no bubbles formed as the enzymes were denatured due to their exposure to high levels of heat
• there were no successful collisions observed as the enzymes had lost their ability to bind the substrate properly
• high temperatures reduce enzyme activity and weaken the hydrogen bonds within them, causing them to lose their shape and ability to function

Question 3

What was the effect of pH in the enzyme lab?

Answer 3

• enzymes work best at an optimal pH level so pH levels that are either too acidic or too basic will most likely denature the enzyme
• acidic pH’s released H+ ions while basic pH’s released OH - ions
• environments with a pH level that differs from the enzyme’s optimal pH will lead to denaturation and slow reaction rate
• Catalase had an optional pH of 7 (pH 3, 5, and 11 gave no enzyme activity and pH 9 gave 3 minutes)

Question 4

What was the effect of enzyme concentration in the enzyme lab?

Answer 4

• as the enzyme concentration increased, the reaction velocity/rate increased as well
• Since there were more active sites for the substrate to bind to, a faster reaction rate was observed whenever the paper disc were soaked for longer (there was an increase of effective collisions)

Question 5

What was the effect of substrate concentration in the enzyme lab?

Answer 5

• Adding more of a substrate to a solution (aka increasing the concentration of the substrate) allows for more collisions, resulting in a faster reaction rate
• After increasing the substrate conc. to a point, it reaches the “V max” where all the enzymes and their active sites are occupied
  ~ at this point, the reaction rate is at its max and it no longer increases (flatlines)
• for example, the fastest enzymatic activity was observed using the 1:10 conc. ( 1 min 33 secs) when compared to the 1:5 conc (3 mins)
  ~ this infers that the optional substrate conc is around 1:10

Question 6

What was the effect of the cold in the enzyme lab?

Answer 6

• cold temperatures reduce the kinetic energy of both enzyme and substrate molecules; this decreases their ability to bind
  ~ cold temps. slow down reaction rates, making the substrate less likely to come in contact with the enzyme
• results in less/fewer forceful effective collisions between enzymes and substrates

Question 7

Do strong acids and strong bases have similar effects on protein solubility and denaturation?

Answer 7

• both strong acids and strong bases lead to denaturation as they both alter the pH of a protein
• changes in an enzyme or protein’s optimal pH can lead to denaturation
• strong acids release H+ ions
• strong bases release OH - ions