AP Bio Buffers

A(n) ______ is a substance with a pH less than 7

• Acid
• Alkaline
• Base
• Buffer

A(n) _______ is a substance with a pH greater than 7.

• Base
• Acid
• Buffer
• Water

Buffer is defined as

• ability to change a pH

• ability to prevent pH from decreasing

• ability to resist a pH increase

• minimizes the changes in the concentrations of H⁺ and OH^-

Why do cells need a buffer system?

• Chemical processes in the cell are sensitive to the concentration of H⁺ and OH^-

• Cells do not have a buffer system

• Cells need acids and bases to survive

• The pH range of cells can withstand large changes

If some process releases acid [H⁺] into the blood, this equilibrium responds by shifting to the left as long as there is HCO₃^-present for the H⁺ to react with, thus removing the excess H⁺ions. What happens after the release of H⁺?

• pH never lowers

• pH is lowered and then immediately restored

• pH raises and then is restored

• ph lowers and remains low

Tags

NGSS.HS-LS1-3

If a process releases base into the blood, which would react with and lower the concentration of the H⁺, the equilibrium shifts to the right as long as there is H₂CO₃, thus replacing the lost H⁺ions. To protect against added base, what needs to be in relatively high amounts?

• HCO₃^-

• OH^-

• H⁺

• H₂CO₃

Why would a potato have a buffering system?

• To survive if its environment changes

• To vary the pH according to the environment

• To keep the pH of the potato low

• To keep the pH very acidic

Tags

NGSS.HS-LS1-3

Why were the biological samples generally good buffers?

• Water is a poor buffer

• They need to maintain a pH of 8.0 at all times

• All living organisms need to maintain homeostasis in terms of pH

• The samples came in liquid form

Tags

NGSS.HS-LS1-3

The alkaline diet is good for those who need to balance their pH. Do you need to balance your pH?

• No. There is a natural buffer system already in my blood that balances my pH.

• Yes. This will lead to a better mood.

Compare the food you should and should not eat on the alkaline diet. Why MIGHT somebody on the diet actually lose weight?

• Adding more fruits and veggies

• Reducing red meat

• Reducing sugary sodas

• All of the above