lipids
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
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.
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