2.3 Carbohydrates and Lipids

Disaccharides

A molecule formed by condensation reactions between two monosaccharides.

Polysaccharides

Important for energy storage and structures

Condensation reaction reaction with glycerol and fatty acids

Forms triglyceride and 3H2O is removed.

What is energy in food used for

generate ATP

How is ATP stored

Glycogen in the liver and muscle tissue, triglycerides in fat cells.

BMI formula

weight (kg) / height (m^2)

Cellulose

A structural polysaccharide that is found in the cell wall of plants. It is a linear molecule composed of β-glucose subunits, this makes it indigestible for most animals. Cows and rabbits can sometimes. Has 1-4 bonds (links)

Starch

An energy storage polysaccharide found in plants. It is composed of α-glucose subunits and exists in one of two forms - amylose or amylopectin. Has 1-4 bonds (links)

Glycogen

An energy storage polysaccharide formed in the liver in animals. It is composed of α-glucose subunits. It is similar to amylopectin in plants but it is more highly branched (per 10 subunits). Has 1-4 and 1-6 bonds (links)

Properties of monosaccharides

Sweet tasting and soluble. Function as immediate energy source for cells.

Properties of disaccharides

Small and soluble function as transport form

Properties of polysaccharides

May be used for energy storage or cell structure, and also play a role in cell recognition.

Fatty acids

long hydrocarbon chains that are found in certain types of lipids

Properties of saturated fatty acids

Linear in structure, originate from animal sources and are typically solid at room temperature.

Properties of unsaturated fatty acids

Bent in structure, originate from plant sources and are typically liquid at room temperature.

Trans fatty acids occurance

Don't commonly occur in nature and are typically produced by and industrial process called hydrogenation.

Trans fatty acid structure

Linear structure and are usually solid at room temperature.

Triglycerides

Largest class of lipids function primarily as long-term energy storage molecules.

How are triglycerides formed?

condensation of glycerol and 3 fatty acids. This forms three molecules of water.

Food example + health effect unsaturated fats

Almonds and vegetables + raises 'good' cholesterol levels.

Food example + health effect saturated fat

Beef and butter + raises 'bad' cholesterol levels

Food example + health effect trans fat

cookies and donuts + raises 'bad' cholesterol levels

Low density lipoproteins (LDL)

Carry cholesterol from the liver to the rest of the body. (increases cholesterol levels)

High density lipoproteins (HDL)

collect excess cholesterol and transport it back to the liver for disposal. (lowers cholesterol levels)

Sugars vs. Lipids

SODAS
Storage (lipids more long term)
Osmolality (Lipids less osmotic pressure on cell)
Digestion (Carbs are easier to digest)
ATP Yield (Lipids store more energy per gram)
Solubility (Carbs are easier to transport in the bloodstream)

Amylose

A type of starch found in plants, made from a-glucose molecules and has 1-4 bonds (links). It is not branched.

Amylopectin

A type of starch found in plants. Made from a-glucose molecules. Contains 1-4 and 1-6 bonds (links). Branched per 20 subunits.

Which sugar polymer can form hydrogen bonds?

Cellulose

Why are trans fatty acids more attractive for processed foods?

Linear chain causes fatty acid tails to pack together more closely, and increase melting point so that the food is less greasy at room temperature.