Carbohydrates and Lipids

What is the general empirical formula for carbohydrates?

CH2O

What is the primary function of carbohydrates?

Source of energy (ATP)

What is the monomer of carbohydrates?

Monosaccharide

What shape do most monosaccharides take?

Ring

How many carbons do pentose and hexose sugars have?

Pentose has 5 carbons; Hexose has 6 carbons.

What functional group makes monosaccharides polar/hydrophilic?

-OH (Hydroxyl) groups

What are the three hexose monosaccharides and their functions?

Galactose (forms lactose), Fructose (sweetens fruits, honey), Glucose (common energy source).

What distinguishes alpha glucose from beta glucose?

Alpha is the monomer of starch and glycogen; beta is the monomer of cellulose.

What is an isomer?

Compounds with the same chemical formula but different arrangements of atoms.

What is the process of forming a disaccharide?

Two monosaccharides covalently bond together and lose water.

What type of bond is found in disaccharides?

Glycosidic bond.

When is a glycosidic bond considered alpha or beta?

Alpha if the bond points down; Beta if it points up.

What are the monomers and function of lactose?

Lactose = Glucose + Galactose (mammal milk sugar).

What are the monomers and function of maltose?

Maltose = Glucose + Glucose (sprouting grains).

What are the monomers and function of sucrose?

Sucrose = Glucose + Fructose (table sugar).

Describe a condensation reaction with an example. What is produced?

2 Glucose → Maltose + Water (water is produced).

Describe a hydrolysis reaction with an example. What is used?

Maltose + Water → 2 Glucose (water is used).

State the solubility of starch, glycogen, and cellulose.

Starch: Insoluble in cold water; Glycogen: Soluble; Cellulose: Insoluble.

What are the structures and function of starch?

Composed of glucose chains (amylose and amylopectin); serves as energy storage in plants.

What are the structures and functions of glycogen?

Highly branched glucose chains; serves as energy storage in animals.

What are the structures and functions of cellulose?

Linear glucose chains; provides structural support.

What is the difference between amylose and amylopectin?

Amylose has linear chains with alpha 1’-4’ bonds; Amylopectin has branched chains with alpha 1’-4’ and 1’-6’ bonds.

What are the building blocks of lipids?

Fatty acids and glycerol.

What is the shape of lipids?

Hydrocarbon chains (fatty acids) and some rings (steroids).

What is the specific bond seen in lipids?

Ester linkage.

What are the functions of lipids?

Waterproofing, plasma membrane structure, regulating metabolic processes, long-term energy storage.

What are the four main types of lipids?

Waxes, Phospholipids, Steroids, Triglycerides.

What is the structure and function of phospholipids?

2 fatty acids, 1 glycerol, 1 phosphate; form plasma membrane.

What is the structure and function of waxes?

Long hydrocarbon chains; provide waterproofing.

What is the structure and function of steroids?

4 fused rings; regulate metabolic processes, signal molecules.

What is the structure and function of triglycerides?

3 Fatty acids bonded to 1 glycerol; serves as long-term energy storage.

What is the comparison of energy storage between carbohydrates and lipids?

Carbohydrates store x energy; Lipids store 2x energy, lighter and no water required.

What are the three types of fatty acids?

Saturated, monounsaturated, polyunsaturated.

What distinguishes saturated from unsaturated fatty acids?

Saturated contain no double bonds, are solid at room temperature; unsaturated have one or more double bonds, are liquid at room temperature.

What are cis and trans isomers of unsaturated fatty acids?

Cis: Hydrogens on the same side, bent shape, healthy; Trans: Hydrogens on opposite sides, straight shape, unhealthy.

Why are trans fats considered unhealthy?

Raise LDL cholesterol, lower HDL cholesterol, increase risk of coronary heart disease and type 2 diabetes.