2.1.4. Enzymes d SYI

What does the term 'optimum pH' mean for an enzyme?

• The pH at which an enzyme operates best
• The pH at which an enzyme is denatured
• The pH that prevents enzyme activity
• The pH with the lowest ion concentration

What happens to enzymes at extreme pH levels?

• They perform faster
• They denature and stop functioning
• They form more active sites
• They become complementary to all substrates

Why does enzyme denaturation occur at extreme pH levels?

• pH extremes create more active sites
• Excess H+ or OH- ions break hydrogen and ionic bonds
• Hydrogen bonds strengthen
• Substrates bind permanently

Which type of bond is affected by changes in pH in enzymes?

• Covalent bonds
• Hydrogen and ionic bonds
• Peptide bonds
• Glycosidic bonds

Which enzyme has an optimum pH of 2?

• Trypsin
• Amylase
• Catalase
• Pepsin

How is pH controlled during experiments on enzyme activity?

• By varying enzyme concentration
• By using buffer solutions
• By changing substrate concentration
• By maintaining a constant temperature

What does iodine solution test for during enzyme experiments?

• The presence of maltose
• The presence of glucose
• The presence of starch
• The presence of peptides

What does it indicate when iodine solution remains orange-brown in an experiment?

• Starch is completely digested
• Substrate concentration is too high
• Enzymes are denatured
• pH is not optimal

Which apparatus is used to measure enzyme reactions at different pH levels?

• Colorimeter
• Water bath
• Buffer solutions
• Microscope

What is the impact of low temperatures on enzyme activity?

• Increased kinetic energy
• Less frequent enzyme-substrate collisions
• Enzymes become denatured
• Substrate saturation occurs