LIPIDS LIPIDS HAVE MANY DIFFERENT FUNCTIONS 1 THEY

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 ACIDS FATS OILS PHOSPHOLIPIDS STEROLS

FATTY ACIDS • ALL OF THEM HAVE AN EVEN NUMBER OF C ATOMS. • COOH - 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 H H H C C C C H H H H

MONOUNSATURATED: HAS ONE DOUBLE BOND BETWEEN CARBON ATOMS COOH H H H C C C C H H H

POLYUNSATURATED: HAS 2 OR MORE DOUBLE BONDS BETWEEN CARBON ATOMS H COOH C C H H H C C C H H H

FATS AND OILS HOW ARE THEY DIFFERENT? AT ROOM TEMPERATURE, FATS ARE SOLIDS AND OILS ARE LIQUIDS HOW ARE THEY SIMILAR? BOTH CONTAIN GLYCEROL.

G L Y C E R O L H H C OH H

PHOSPHOLIPIDS ARE IMPORTANT IN CELL MEMBRANES

STEROIDS ARE COMPOSED OF 4 CARBON RINGS 3 11 2 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): THE PRODUCTION OF PLAQUE “ON” ARTERY WALLS LEADS TO

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

CHOLESTEROL VALUES • TOTAL CHOLESTEROL • LDL 130 • HDL 45 • TRIGLYCERIDES BELOW 200 BELOW ABOVE 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. AGE CHOLESTEROL INCREASES WITH AGE.

3. EXERCISE

4. SMOKING

5. HEREDITY

6. STRESS INCREASES CHOLESTEROL LEVELS (there is a stress test for you to take in the next exercise)

NUCLEIC ACIDS THERE ARE TWO DNA (DEOXYRIBONUCLEIC ACID) RNA (RIBONUCLEIC ACID) RNA DNA

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 • r. RNA – Ribosomal RNA • t. RNA – Transfer RNA • m. RNA – Messenger RNA

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