pH and Energy

Objectives

• Define acids, bases, and pH
• Discuss the importance of pH in life
• Recognize the structure of ATP
• Compare the roles of ATP and glucose

The concentration of hydronium ions relates to acidity.

In pure water the concentration of hydronium ions is very low. The pH is 7 on a scale of 1 to 14.

Acids have a pH less than 7. Bases have a pH greater than 7.

The higher the concentration of hydronium ions, the lower the pH (the more acidic).

Acids are sour, but remember, no eating lab chemicals! Bases taste bitter.

A low concentration of hydronium ions results in a higher pH (more basic).

Remember enzymes? They only function properly at certain pHs.

The enzyme pepsin works in the acidic stomach. Enzymes in the intestine need a basic environment, so the pancreas secretes a base.

Objectives

• Define acids, bases, and pH
• Discuss the importance of pH in life
• Recognize the structure of ATP
• Compare the roles of ATP and glucose

Important energy-carrying molecules

• Glucose
• Adenosine triphosphate (ATP)

Remember glucose from last week?

• It can be carried through your blood
• It's produced during photosynthesis

ATP stores less energy than glucose, but the structure is more complex.

Energy is obtained when ATP is converted to ADP (adenosine diphosphate).