Chemistry Exam 3: Lipids

organic substances not soluble in H2O

usually less dense than H20

1. energy storage - long term energy

2. membrane components - controls entry and exit

• 3. messengers (primary - steriods)
• (secondary - protaglandins and thromboxanes)

1. simple (fats and waxes)

2. Complex

3. Steriods

4. secondary messengers (Prostaglandins, thromboxanes, leukotrienes)

Triester of glycerol and long chain carboxylic acids called fatty acids.

inculdes alchohol, fatty acid, ester

Animal Fats - solid at room temp....saturated fat....only single bonds

Plant/Fish - liquid at room temp...unsaturated fat....double bonds...don't stack well...reactive

A carbon-carbon double bond cn be reduced by treating them with H₂ and a metal catalyst.

• **Unsaturated fats can be converted to saturated fats by this method**

When an unsaturated fat goes bad due to exposure of the double bond to O²

Turning some molecules into aldehydes, causing foul smell and taste.

Keep oils refridgerated, in dark bottles, limit time open to air.

1. Phospholipids - alcohol, fatty acid, phosphate

2. Glycolipids - alcohol, fatty acid, carbohydrate

• 1. cholesterol
• 2. Proteins
• 3. Carbohydrate chain
• 4. Glycoprotein
• 5. Glycolipid

Remember....membranes are not static structures.

1. Gap Junction - allows control of passive transport

2. Facilitated transport - a transporter (protein) assists in crossing

3. Active transports - ions through a gradient.

Facilitated and Active are more selective.

Usually controlled by Ca, Na, K

Myelin sheath - lipid coating around the nerve axons.

MS - overtime, the myelin sheath deteriates.

Symptoms - muscle weariness, lack of coordination, vision loss....death

**Demyelinated axons cannot conduct nerve impulses**

its ring structure.

6665

When some of the enzymes needed to decompose the complex carbs are defective or missing.

Complex carbs accumulate and cause enlarged liver and spleen, mental retardation, blindness, early death.

Ex: Gucher's disease, Krabbe's leukodystrophy, Fabry's disease, Tay-Sachs disease, Niemann-Pick disease.

The most abundant and most important steriod in the human body

-plasma membrane component (RBC)

-raw material for synthesis of other steriod hormones (sex, adrenolcorticoid) and bile salts

LDL - transport of cholesterl starts out as very large VLDL particles...VLDL becomes LDL.


HDL - these transport cholesterol from peripheral tissues to the liver and transfer cholesterol to LDL.

LDL - low density lipoprotein - bad cholesterol - contains 25% protein, 50% cholesterol, larger in diameter

HDL - high density lipoprotein - good cholesterol - contains 33% protein, 30% cholesterol

Chemical Communication

-Synthetic testosterone

-Used to build muscle

-Side effects - acne, liver tumors, facial hair, baldness, deepening of voice, menstrual irregularities.

Illegal use

Tricks the body into thinking its pregnant by using progesterone-like compounds.

Synthetic progesterone + Estradiol compounds (prevents irregularity) = Birth control

Oxidation products of cholesterol.

Main function: Remove excess cholesterol by breaking it down

Think bile salts is to cholesterol in the sm intestines as detergent is to dirty clothes - form EMULSIONS, which is essential for digestion of fats.

• 1. Prostaglandin:
• -stimulates uterine contractions, induces labor, lowers BP, treat asthma, decongestent

• 2. Thromboxanes:
• -induce platelet aggregation

• 3. Leukotrienes:
• -occur in WBC, produce long muscle contractions, can cause asthma attacks and inflammation and fever