Triglycerides

Adipose tissue is composed of adipose cells (adipocytes) that store insoluble fat in the form of triglycerides for long-term energy storage

Can form a thick layer under the skin, acting as a shock absorber and thermal insulator

When energy is needed, the stored triglycerides can go through hydrolysis reaction

--> releasing glycerol and fatty acids

They can be used in cell respiration to produce twice as much energy than sugar.

Function of Triglycerides in Adipose Tissue

Endotherms (birds and mammals) need to maintain a steady internal temperature regardless of their environmental temperature

They have thick adipose tissue called blubber

Blubber is found between the skin and muscle

Triglycerides are poor conductors of heat

Blubber helps trap the heat generated by the inner metabolic activities

	Triglycerides	Carbohydrates
Type and location of tissue when energy stores are found	Adipose tissue beneath the skin and around organs in endotherms or seeds. Plants and cold-blooded animals store unsaturated fats, endotherms store saturated fats.	In skeletal muscle tissue and in the liver as glycogen, or as simple sugars (glucose/fructose) dissolved in blood. Plants in the form of starch.
Energy contained per gram of storage form	Twice as much energy per gram, account for less mass than the equivalent energy in carbohydrates. This is because they can be oxidised.	Half as much energy contained per gram. Glycogen storages therefore account for a higher body mass.
Short or long-term energy storage?	Long Term	Short term
How soluble and easy to transport are the storage forms?	Insoluble in water. Can't be mobilised quickly. Do not cause osmotic consequences.	Glucose is soluble and can easily be transported around, glycogen and starch are much less soluble and therefore used as storage form. No osmotic effect.