Biological Macromolecules; Carbohydrates and Lipids

Biological Macromolecules

Large molecules built from smaller organic molecules, necessary for life.

Carbohydrates

An important part of our diets that provide energy to the body, especially through glucose.

Lipids

One of the four main types of biological macromolecules.

Proteins

One of the four main types of biological macromolecules.

Nucleic acids

One of the four main types of biological macromolecules. (makes DNA and RNA)

Dehydration synthesis

Process where monomers combine via covalent bonds to form polymers, releasing water as a byproduct.

Hydrolysis

Process where polymers break down into monomers by adding a water molecule.

Monomers

Single subunits that combine to form polymers.

Polymers

Large molecules formed from the combination of monomers.

Stoichiometric formula for carbohydrates

(CH2O)n, where n is the number of C atoms present, representing a ratio of C:H:O as 1:2:1.

Monosaccharides

Simple sugars, with glucose being the most common.

Disaccharides

Carbohydrates formed from two monosaccharides.

Polysaccharides

Carbohydrates formed from multiple monosaccharides.

Triose

A monosaccharide with 3 carbons.

Pentose

A monosaccharide with 5 carbons.

Hexose

A monosaccharide with 6 carbons.

Aldose

A monosaccharide that has an aldehyde group (R-CHO).

Ketose

A monosaccharide that has a ketone group (RC(=O)R').

Glucose

A simple sugar (C6H12O6) that is crucial for cellular respiration and photosynthesis.

Cellular respiration

Process where glucose breaks down to release energy, used to make ATP.

Photosynthesis

Process where plants synthesize glucose from CO2 and H2O.

Enzymes

Proteins that catalyze dehydration and hydrolysis reactions.

Sucrase, amylase, lactase, maltase

Enzymes that break down carbohydrates.

Proteases

Enzymes that break down proteins, such as pepsin and peptidase.

Lipases

Enzymes that break down lipids.

Monosaccharides

Simple sugars, glucose most common.

Glucose

C6H12O6; breaks down in cellular respiration to release energy, used to make ATP.

Photosynthesis

Process by which plants synthesize glucose from CO2 and H2O.

Stoichiometric formula of carbohydrates

(CH2O)n, where n is the number of C atoms present; ratio of C:H:O is 1:2:1.

Disaccharides

Form when 2 monosaccharides undergo a dehydration reaction (dehydration synthesis).

Maltose

Disaccharide composed of 2 glucose monomers.

Lactose

Disaccharide composed of glucose and galactose; found in milk.

Polysaccharides

A chain (branched or unbranched) of monosaccharides linked by glycosidic bonds.

Starch

Polysaccharide in which plants store sugars, composed of amylose and amylopectin (glucose polymers).

Glycogen

Animal form of starch; highly branched; stored in liver and muscle cells.

Glycogenolysis

Process where glycogen breaks down to release glucose when blood glucose levels decrease.

Cellulose

The most abundant natural biopolymer; found in plant cell walls, gives structure/support.

Cellulase

Enzyme secreted by bacteria and protists in the digestive systems of some organisms to break down cellulose.

Chitin

A nitrogen-containing polysaccharide that makes up the exoskeletons of arthropods and is found in fungal cell walls.

Fiber

Insoluble part of carbohydrates.

Caloric content of carbohydrates

Carbohydrates provide 4.3 Kcal/g.

Caloric content of fats

Fats provide 9 Kcal/g.

Carbohydrates

Organic compounds consisting of carbon, hydrogen, and oxygen, typically in a 1:2:1 ratio.

Lipids

Largely nonpolar hydrocarbons that are hydrophobic and serve various functions such as long-term energy storage.

Proteins

Large biomolecules composed of one or more long chains of amino acid residues.

Nucleic acids

Biological macromolecules essential for all known forms of life, including DNA and RNA.

Fats

Composed of glycerol and fatty acids, used for long-term energy storage.

Glycerol

An organic compound (alcohol) with the formula C3H8O3, consisting of 3 carbon atoms, 5 hydrogen atoms, and 3 hydroxyl groups.

Fatty acids

Long chains of hydrocarbons with a hydroxyl group at one end, typically containing 4-36 carbon atoms.

Saturated fatty acids

Fatty acids that contain only single bonds between carbon atoms.

Unsaturated fatty acids

Fatty acids that contain one or more double bonds between carbon atoms.

Oils

Most unsaturated fats that are liquid at room temperature.

Monounsaturated fats

Fats that contain one double bond (C=C) in their structure, such as olive oil.

Polyunsaturated fats

Fats that contain multiple double bonds (C=C) in their structure.

Trans fats

Fats that are created by hydrogenating oils, making them semi-solid at room temperature.

Omega fatty acids

Essential fatty acids that must be obtained from the diet, such as omega-3 fatty acids.

Alpha-linoleic acid (ALA)

An example of an omega-3 fatty acid that is polyunsaturated.

Waxes

Composed of long fatty acid chains ester bound to long-chain alcohols, providing a hydrophobic coating.

Phospholipids

Molecules that are amphipathic, having both hydrophobic and hydrophilic regions.

Phospholipid bilayer

A double layer of phospholipids that forms the fundamental structure of cell membranes.

Steroids

Lipids characterized by a fused ring structure, consisting of four linked carbon rings.

Cholesterol

The most common steroid, synthesized by the liver, and a precursor to steroid hormones and Vitamin D.