LIPIDS

LIPIDS HAVE MANY DIFFERENT FUNCTIONS

1. THEY ACT AS ENERGY SOURCES

2. THEY CUSHION THE BODY.

3. THEY INSULATE THE BODY.

THERE ARE 5 GROUPS OF LIPIDS

FATTY ACIDSFATSOILS

PHOSPHOLIPIDSSTEROLS

FATTY ACIDS• ALL OF THEM HAVE AN EVEN NUMBER OF C

ATOMS.

• COOH - C-C-C-C-C-C-C-C-C

• ALL OF THEM HAVE A CARBOXYL GROUP (-COOH) ON ONE END.

FATTY ACIDS

ARE CLASSIFIED IN 2 WAYS

1. BY THE LENGTH OF THE CARBON CHAIN

2. BY HOW SATURATED THEY ARE WITH H ATOMS

THE LENGTH OF THE CARBON CHAIN

SHORT CHAIN:

10 OR FEWER C ATOMS. Eg. BUTTER

LONG CHAIN

12-18 C ATOMS. Eg. ANIMAL FATS &

VEGETABLE OILS.

EXTRA-LONG CHAIN

20 OR MORE C ATOMS. Eg. FISH OILS.

HOW SATURATED THEY ARE WITH H ATOMS

THERE ARE 3 DEGREES OF SATURATION

SATURATED

MONOUNSATURATED

POLYUNSATURATED

SATURATED: HAVE AS MANY H ATOMS AS POSSIBLE

COOH

C C C C C C C

H H H H H H H

H

HHHHHHH

MONOUNSATURATED: HAS ONE DOUBLE BOND BETWEEN CARBON

ATOMS

COOH

C C C C C C C

H H H H H H H

H

HHHHH

POLYUNSATURATED: HAS 2 OR MORE DOUBLE BONDS BETWEEN CARBON ATOMS

COOH

C C C C C C C

H H H H H H

H

HHHH

FATS AND OILS

AT ROOM TEMPERATURE, FATS ARE SOLIDS AND OILS ARE LIQUIDS

HOW ARE THEY DIFFERENT?

HOW ARE THEY SIMILAR?BOTH CONTAIN GLYCEROL.

GLYCEROL

OH

OH

OH

H

H

H

H

H

C

C

C

PHOSPHOLIPIDSARE IMPORTANT IN CELL MEMBRANES

STEROIDS

ARE COMPOSED OF 4 CARBON RINGS

11 2

3 4

FUNCTIONS OF STEROIDS• COMPOSE THE CELL MEMBRANE

• IMPORTANT IN THE PRODUCTION OF HORMONES

• THE RAW MATERIAL OF VITAMIN D

• NECESSARY FOR BILE SALTS

• THE MOST IMPORTANT STEROID IS CHOLESTEROL

• WHAT IS CHOLESTEROL?

• DEFINITION: A STEROID FOUND IN ANIMAL FATS AND MOST BODY TISSUES; MADE BY THE LIVER.

WHITE AND FATTY IN NATURE.

PRIMARY SOURCES OF CHOLESTEROL:

• EGGS

• RED MEAT

• CHEESE

• ORGAN MEATS

• THE LIVER PRODUCES CHOLESTEROL

TYPES OF CHOLESTEROL

LDL (BAD CHOLESTEROL): LEADS TO THE PRODUCTION OF PLAQUE “ON” ARTERY WALLS

HDL (GOOD CHOLESTEROL): CLEANS UP CHOLESTEROL FROM THE VESSELS.

CHOLESTEROL VALUES

• TOTAL CHOLESTEROL BELOW 200• LDL BELOW 130• HDL ABOVE 45• TRIGLYCERIDES BELOW 200

WHY IS CHOLESTEROL BAD?

IT HAS BEEN LINKED TO CHD (CORONARY HEART DISEASE)

WHAT AFFECTS BLOOD CHOLESTEROL LEVELS?

1. DIET• AN EGG HAS 255 Mg. CHOL• 1 TBsp BUTTER HAS 12 Mg. CHOL• 1 C WHOLE MILK HAS 25 Mg. CHOL

2. AGECHOLESTEROL INCREASES WITH AGE.

3. EXERCISE

4. SMOKING

5. HEREDITY

6. STRESSSTRESS INCREASES CHOLESTEROL LEVELS (there

is a stress test for you to take in the next exercise)

NUCLEIC ACIDSTHERE ARE TWO

DNA (DEOXYRIBONUCLEIC ACID)RNA (RIBONUCLEIC ACID)

DNARNA

DNA RNA  

Nitrogen bases are arranged in two groups:

• Purines – double ringed structures – including Adenine and Guanine

• Pyrimidines – single ringed structures – including Thymine (DNA only), Cytosine, and Uricil (RNA only)

Three types of RNA

• rRNA – Ribosomal RNA• tRNA – Transfer RNA• mRNA – Messenger RNA

• Adenine always bonds with Thymine (except if you are making RNA then it is Uricil)

• Guanine always bonds with Cytosine