Cell Biology: Cell Compounds and Biological Molecules

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Cell Biology: Cell Compounds and Biological Molecules Lesson 2 – Acids, Bases, and Buffers (Inquiry into Life pg. 29-30)

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Cell Biology: Cell Compounds and Biological Molecules. Lesson 2 – Acids, Bases, and Buffers ( Inquiry into Life pg. 29-30 ). Today’s Objectives. Describe the role of acids, bases, and buffers in biological systems in the human body, including: Differentiate among acids, bases, and buffers - PowerPoint PPT Presentation

Transcript of Cell Biology: Cell Compounds and Biological Molecules

Page 1: Cell Biology: Cell Compounds and Biological Molecules

Cell Biology:Cell Compounds and Biological Molecules

Lesson 2 – Acids, Bases, and Buffers (Inquiry into Life pg. 29-30)

Page 2: Cell Biology: Cell Compounds and Biological Molecules

Today’s Objectives Describe the role of acids, bases, and buffers

in biological systems in the human body, including: Differentiate among acids, bases, and buffers Describe the importance of pH to biological

systems in the human body

Page 3: Cell Biology: Cell Compounds and Biological Molecules

Acids and Bases

When water ionizes, it releases an equal number of hydrogen ions (H+) and hydroxide ions (OH-).

Ionization is the process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or ions

Page 4: Cell Biology: Cell Compounds and Biological Molecules

Acids and Bases Acidic Solutions (High H+ Concentrations)

Acids are substances that dissociate in water, releasing hydrogen ions (H+).

An example:

HCl H+ + Cl-hydrochloric acid

Page 5: Cell Biology: Cell Compounds and Biological Molecules

Acids and Bases Basic Solutions (Low H+ Concentrations)

Bases are substances that dissociate in water, releasing hydroxide ions (OH-) or take up hydrogen ions (H+).

An example:

NaOH Na+ + OH-sodium hydroxide

Page 6: Cell Biology: Cell Compounds and Biological Molecules

Acids and Bases The pH Scale

Ranges from 0 - 14

A pH below 7 is acidic [H+] > [OH-]

A pH above 7 is alkaline [OH-] > [H+]

A pH of 7 is neutral [H+] = [OH-]

Page 7: Cell Biology: Cell Compounds and Biological Molecules

The pH Scale

Page 8: Cell Biology: Cell Compounds and Biological Molecules

Acids and Bases

The pH Scale

Each unit change in pH represents a change of 10X

Page 9: Cell Biology: Cell Compounds and Biological Molecules

Buffers and pH A buffer is a chemical(s) that keep pH within

normal limits. Bicarbonate ions (HCO3

-) and carbonic acid (H2CO3) found in human blood buffers the pH to 7.4 If bloods pH drops to 7, acidosis results If blood pH rises to about 7.8, alkalosis results Both conditions can be life threatening

Our bodies produce natural buffers that help keep our blood at a healthy pH

Page 10: Cell Biology: Cell Compounds and Biological Molecules

Buffers and pH

If hydrogen ions (H+) are added to the blood, this reaction occurs:

H+ + HCO3- H2CO3

If hydroxide ions (OH-) are added to the blood, this reaction occurs:

OH- + H2CO3 HCO3- + H2O

H+ ions removed from blood, raises pH

OH- ions removed from blood, lowers pH

bicarbonate ion

carbonic acid

Page 11: Cell Biology: Cell Compounds and Biological Molecules

Homework Read pg. 31-40 – Carbohydrates, Lipids,

Proteins, Nucleic Acids Create Flashcards for all bold terms found in

these pages Each flash card should have the word on the

front side The back side should have:

Picture/diagram Function Composition Location