Provide energy to the body, particularly through glucose, a simple sugar. Carbohydrates also have other important functions in humans, animals, and plants.
Protein
Helps repair and build your body's tissues, allows metabolic reactions to take place and coordinates bodily functions.
Lipids
Acting as chemical messengers, storage and provision of energy
Nucleic acid
Storage and expression of genetic information
Carbohydrates
Most abundant class of organic compounds found in all living things. Include sugars, starches, cellulose, and many other compounds. They have a H:C:O ratio of 2:1:1. Cn(H2O)n
Functions of carbohydrates
It serves as the backbone of other molecules
It serves as stored energy (such as starch, cellulose, glycogen)
It is the most common source of energy in the body
It combines with proteins (glycoproteins) to form structural components of living cells
Role of carbohydrates in photosynthesis
1. Carbohydrates are synthesized by green plants during photosynthesis, a complex process in which sunlight provides energy to convert CO2 and H2O into glucose plus oxygen
2. Many molecules of glucose are then chemically linked for storage by the plant in the form of starch
3. Cellulose is present in the cell wall of a plant and helps the cell maintains the shape of a plant
Classifications of carbohydrates
Monosaccharides
Disaccharides
Polysaccharides
Monosaccharides
Simplest form of sugar, further classified as either aldoses or ketoses
Monosaccharides
Glucose
Galactose
Fructose
Disaccharides
Two monosaccharides joined together
Polysaccharides
Long chain of monosaccharides joined together
Polysaccharides
Glycogen
Starch
Cellulose
Triglycerides are the most abundant class of lipids in plants & animals, making up more than 95 percent of lipids in the diet
Triglycerides
Composed of a glycerol backbone and fatty acids
Fatty acids
Consist of a long, hydrophobic nonpolar hydrocarbon "tail" and a hydrophilic polar carboxylic acid functional group at the "head"
Saturated fatty acids have no carbon-carbon double bonds and are solid at room temp
Unsaturated fatty acids contain one or more double bonds and exist as liquids at room temperature
Phospholipids
Fundamental building blocks of cellular membranes, consisting of a hydrophilic head and hydrophobic tail
Phospholipids
Form a bilayer where the hydrophobic tails point towards each other on the interior and only the hydrophilic heads are exposed to the water
Waxes
Composed of fatty acids combined with a much longer alcohol molecule, used as polishers, ointments, and to protect surfaces
Steroids
Simple lipids with a backbone structure consisting of four fixed carbon rings, such as cholesterol
Amino acids
The building blocks of proteins, can be classified as essential or nonessential
Proteins
Large molecules consisting of long complex chains of amino acids linked by strong polypeptide bonds
Functions of proteins
Structure
Hormones
Transport
Storage
Catalysis
Protection
Movement
DNA (deoxyribonucleic acid)
Chemical which carries the instructions for all traits of an organism, occurs as a double-stranded helix
RNA (ribonucleic acid)
Synthesized from DNA and is responsible for protein synthesis, serves as a messenger of the DNA's genetic message to the cytoplasm of a cell where proteins are synthesized
DNA, along with the instructions it contains, is passed from adult organisms to their offspring during reproduction
Hydrogen bonds hold the DNA strands together, forming between A and T base pairs as well as between C and G base pairs