2

BIOLOGICALLY IMPORTANT

MACROMOLECULES

Standard SB1~ Students will analyze the nature of the

relationships between structures and functions in living cells.

(c) Identify the function of the four major macromolecules

(i.e., carbohydrates, proteins, lipids, nucleic acids).

3

Organic vs. Inorganic

All compounds can be separated into two

groups:

Inorganic

• Doesn’t contain carbon

• Non-living

• Examples: Oxygen gas, metals, rocks, water

Organic

• Contains carbon

• Living (or dead)

• Examples: wood, grass, diamonds, petroleum

4

What are Macromolecules? Very large COMPOUNDS called polymers

Made of repeating units called monomers

Polymers are the train – monomers are the

train cars.

5

Combining monomers to make polymers

Dehydration

synthesis

Each monomer is

added as a water

molecule is

released

Energy is required

Anabolic process

6

Breaking polymers into monomers

Hydrolysis

The reverse of

dehydration

synthesis

Breaks bonds

between

monomers by

adding water

molecules

Energy is released

Catabolic process

7

MACROMOLECULES

There are FOUR biologically important

macromolecules:

Carbohydrates

Lipids

Nucleic Acids

Proteins

8

Carbohydrates Made of C, H, & O

Ratio of one oxygen and two hydrogen atoms for each carbon atom (CH2O)n

MONOMER: monosaccharides

Monosaccharides are the fuels for cellular work

Disaccharides are substances such as sucrose(table sugar) and maltose (brewing sugar)

Polysaccharides are substances such as starch (in plants) and glucose (in animals)

All sugars end in - OSE

9

Carbohydrates Functions

Main energy source in organisms

Structural component in plants

Types Sugars

• gives off energy when broken down

• Cellulose twisted chain of sugars, not digestible by humans

• Chitin hard cellulose found in the exoskeletons of invertebrates

• Ex. Sucrose, fructose, glucose

Starches • used as a storage molecule for sugars

• Many athletes eat these before events

• Ex. Bread, rice, pasta, corn

11

Lipids

Made of C, H, O

MONOMER: fatty acid and glycerol

Commonly called fats, oils, & waxes

Functions

Storage of energy

Parts of biological membranes

Water proof coverings

Chemical messengers (steroids)

Insoluble in water

Ex. butter, oil, hormones, steroids, egg yolk,

phospholipids in cell membrane

12

Can be saturated or unsaturated

Saturated fats (lard) lack double bonds

They are solid at room temperature

Fatty acid

Figure 3.8C

Figure 3.8B

13

Nucleic acids Made of C, H, O, N, & P

MONOMER: nucleotides Nucleotides are made up of

• a 5-carbon sugar

• phosphate group

• a nitrogen base

Functions Store hereditary information

Transmit hereditary information

Two types RNA (ribonucleic acid)

DNA (deoxyribonucleic acid)

14

Proteins Made of C, H, O, & N

MONOMER: amino acids

Functions Control the rates of chemical reactions (enzymes)

Provide support

Contractile proteins (muscles)

Storage and transport of molecules

Includes substances such as enzymes, insulin, meats, amino acids (VERY DIVERSE GROUP)