A&P CH2 PG14-15

What is a buffer?

A system that:

• Resists pH changes

• Accepts or releases H+ ions

• Keeps pH stable

Why are buffers necessary?

Without it:

• Small amounts of acid/base would cause dramatic pH changes

• Cells would be damaged

• Enzymes would stop working

What are components of a buffer?

They contain:

• A weak acid

• A weak base

These work together to control H+ levels

What happens if blood becomes too acidic?

The base part of the buffer responds

1. It binds H+ and removes it (because acidic = too many H+ ions)

2. Once removed, pH roses back to normal

What is the main buffer system in blood?

Bicarbonate-Carbonic Acid Buffer System

What is the equation for the bicarbonate/carbonic acid buffer system?

CO2 + H2O ←→ H2CO3 ←→ H+ + HCO3-

What are the components of the Bicarbonate -Carbonic Acid Buffer System? (3)

1. Carbonic acid

2. Bicarbonate

3. Acid

Name these components:

1. H2CO3

2. HCO3-

3. H+

1. Carbonic acid (H2CO3)

2. Bicarbonate (HCO3-)

3. Acid (H+)

When blood is too _____ too many _+ present

1. Acidic

2. H+

Bicarbonate binds __ when blood is too acidic

H+

what does the equation look like when blood is too acidic (Low pH)

H+ + HCO3- → H2CO3

When blood is too _____, there are too little _+

1. Basic

2. H+

What does the equation look like when blood is too Basic (High pH)?

H2CO3 → H+ + HCO3-

What is:

HCO3-

Bicarbonate

What is:

H2CO3

Carbonic Acid

What does Bicarbonate do?

1. Removes excess acid

2. Raises pH

3. Acts as a base

What does carbonic acid do ?

1. Releases H+

2. Lowers pH

3. Acts as acid

If bicarbonate binds H+, what happens to pH?

1. pH rises

2. Less acidic

3. H+ decreases

If bicarbonate binds to H+ and the pH rises, is this a positive or negative feedback?

Negative feedback

What are inorganic compounds

No carbon back bone

What are examples of inorganic compounds

Water

Salts

Acids

Bases

What are organic compounds?

1. Compounds that contain carbon + hydrogen

2. Built around carbon chains

What are examples of carbon compounds

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic acids

Organic chemistry = _ _ _ _

Life

Carbohydrates

C H O

What are the elements in all carbohydrates?

1. Carbon

2. Hydrogen

3. Oxygen

What is the usual ratio for C H O?

1:2:1

Ex: C6H12O6

What is the major function of carbohydrates?

Energy source

Carbohydrates are classified by the number of sugar units they contain. Name three:

1. Monosaccharides (simple sugars)

2. Disaccharides (double sugars)

3. Polysaccharides (many sugars)

What is a monosaccharide?

1. A single sugar molecule

2. The simplest form of carbohydrate

3. Cannot be broken down into smaller sugars

Name three examples of monosaccharides:

1. Glucose

2. Fructose

3. Galactose

What is a simple sugar?

1. A sugar made of one unit

2. Easily absorbed

3. Quickly used for energy

What is a disaccharide?

1. Two monosaccharides bonded together

2. Formed by dehydration synthesis

Name three types of disaccharides:

1. Sucrose (table sugar)

2. Lactose (milk sugar)

3. Maltose (grain sugar)

How is SUCROSE formed?

Glucose + fructose

How is LACTOSE formed?

Glucose + Galactose

How is MALTOSE formed?

Glucose + Glucose

What happens when disaccharides are formed?

Water is released in each reaction.

What is a polysaccharide?

1. A long chain of monosaccharides

2. Many sugars bonded together

Name three types of polysaccharides:

1. Glycogen

2. Starch

3. Cellulose

What is the function of glycogen?

Energy storage in animals

What is the function of starch?

Energy storage in plants

What is the function of cellulose

Structural support in plants

Anabolic or catabolic?

Building polysaccharides from glucose

Anabolic

Hydrolysis or dehydration?:

Building polysaccharides from glucose

Dehydration synthesis

If starch is broken down to glucose, water is added to starch in a process called __________

Hydrolysis