Intro to Biomolecules, Polymers, and Carbohydrates

• Biomolecules are large molecules.
• Biomolecules are the building blocks of life and provide structural support to cells.
• They are made when smaller molecules link together in chains
• Plants and animals, etc, are organized into these.
• The four major types of biomolecules are carbohydrates, proteins, nucleic acids, and lipids.

Polymers

• Polymers are large molecules made up of smaller units called monomers.
• Polymers are chains of molecules.
• Lipids do not undergo polymerization, unlike the other three biomolecule types.

Carbohydrates

• Carbohydrates Are the most abundant biomolecule in the biosphere.
• It is a main source of instant energy
• Carbohydrates contain carbon, hydrogen, and oxygen atoms
• Used as a source of energy for the cells, organs, and tissues.
• This is a derivative of the French term 'hydrate de Carbone meaning 'hydrate of carbon
• Carbohydrates are Hexagon shaped.
• Also a major component of bacterial cell walls and makes up chitin (fungi cell wall and insect exoskeleton).
• One of the basic components of food.
• Involved in fat metabolism and prevents ketosis.
• Inhibits the breakdown of proteins for energy.
• Enzymes called amylase break down starch into glucose.

Monosaccharides

• Monosaccharides are the smallest units of carbohydrates (one molecule).
• Cannot be broken down into simpler units by hydrolysis.
• They are classified into either polyhydroxy aldehyde (aldose) or polyhydroxy ketones (ketose).
• Naturally occurring monosaccharides have three to seven carbon atoms named triose, tetrose, pentose, hexose, and heptose.
• The three most common monosaccharides are glucose, fructose, and galactose.

Glucose

• Glucose (Dextrose)is the starting material of cellular respiration and primary source of energy for metabolic activities in cells.
• It is also called blood sugar, as it is the primary sugar in blood and grape sugar.
• Used in hospitals when oral nutrition is not possible in the form of saline through the veins.

Galactose

• Galactose is called brain sugar, being made up of glycoproteins that can be found in the brain and nerve proteins.
• Also present in chemical markers that distinguish blood types.

Fructose

• Fructose is twice as sweet as glucose.
• Commonly called fruit sugar, as it is commonly found in fruits.
• It is absorbed by the circulatory system and transported to the different body cells.

Disaccharides

• Disaccharides are made up of two monosaccharides.
• Organisms have to break them down to be used for metabolism.
• The three most common Polysaccharides are Sucrose, Lactose, and Maltose.

Sucrose

• Sucrose is table sugar.
• Purified from sugar cane or sugar beets.
• Is sweeter when broken down into individual components since fructose is twice as sweet as glucose.

Lactose

• Lactose is often called milk sugar.
• Made up of glucose and galactose.
• It is 1/6 as sweet as sucrose.
• Digested by bacteria in the large intestine, which produce carbon dioxide, leading to excess external gas.

Maltose

• Maltose is made up of two glucose molecules.
• Also found in malt which is found in grain used for brewing beer.
• It is 1/3 as sweet as sucrose.

Polysaccharides

• Polysaccharides are made up of several monosaccharides joined together by glycosidic bonds.
• Common polysaccharides are starch, glycogen, and cellulose.

Starch

• Starch is an energy storage molecule for plants.
• Occurs as microscopic granules in the cells of roots, tubers, and seeds of plants.
• Serves as an important food source for humans.
• Major energy source for animals and humans.
• When heated, it converts into dextrin, which has good adhesive quality (used in glue).

Glycogen

• Glycogen stores energy for animals and humans.
• When excess glucose is present, some is converted into fat (for storage), and some into glycogen.
• Found in muscles.
• Acts as an instant form of energy.
• Concentrated in the liver and can constitute 10% of the dry weight of the liver.

Cellulose

• Cellulose makes up plant cell walls.
• It is insoluble in water and indigestible by humans.
• Straight chains of polysaccharides without any branches like starch but with a different way of attaching.
• Most animals and humans have enzymes to digest starch but don't have enzymes to digest cellulose.
• Common sources of carbohydrates include fruits (fructose); dairy products (galactose); milk and other dairy products (lactose); cereal, beer, potatoes, processed cheese, pasta(maltose).
• Sucrose is naturally obtained from sugar and honey which contain small amounts of vitamins and minerals.

Lipids

• Lipids are Insoluble in water but soluble in nonpolar solvents.
• They are Chemicals extracted from nonpolar solvents from plants and animal tissue.
• Lipids have a wide variety of structural types, which include carboxylic acids (fatty acids), triacylglycerol (neutral fats), phospholipids, waxes, steroids, and prostaglandins.
• Classified based on their reaction to their base.
• There are two classes: saponifiable and non-saponifiable.

Saponifiable lipids

• Saponifiable lipids can be hydrolyzed by a base (like fats, oils, and waxes).

Non-saponifiable lipids

• Non-saponifiable lipids cannot be broken down by base hydrolysis (like steroids, cholesterol, and prostaglandins).

Fats and Oils

• Fats and oils are the most abundant lipid compounds and the most abundant lipids in nature.
• Formed from the chemical reaction between three fatty acids and glycerol (alcohol).
• Called triglycerides or triacylglycerols due to how they are formed.
• Provide energy for living organisms, insulate organs, and transport fat soluble vitamins through the blood.
• At room temperature, fats are solid and oils are liquid. – Animal fats are mixed fats and contain more saturated (no double bond) fatty acids than unsaturated (with one or more double bonds).
• Fatty acids are molecules with long nonpolar hydrocarbon chains typically 12 to 24 atoms of carbon long and a carboxylic acid group at the end of the chain.
• Fats and oils are physically different but molecularly similar.
• Made up of esters of glycerol and three fatty acid molecules which may be the same or different.
• This reaction can also produce a water molecule for each fatty acid joined to glycerol.
• This process is the basis for forming animals fats and plant oils.
• In most instances, the process is catalyzed by enzymes.
• All fatty acids in the human body are transported in the form of triglycerides.

Waxes

• Waxes are harder and less greasy than fats.
• Esters of long fatty acids and monohydric (one hydroxyl group) alcohols.
• They have high melting points and are solid in room temperature.
• Waxes are unreactive and insoluble in water.
• They are a good coating material due to their repellency, impermeability, and low toxicity.
• Plants use it as a protective covering against microorganisms and to help in keeping them pliable and waterproof.
• Humans have them formed by glands in the outer ear canal to trap dust and dirt particles.

Phospholipids

• Phospholipids Form part of the cell membrane.
• Important in transporting lipids in the body.
• Are esters of glycerol where the glycerol is attached to two fatty acids and a phosphate group.
• Have hydrophilic heads because of the phosphate group and a hydrophobic tail due to the fatty acid hydrocarbon chain.
• Glycerol-based phospholipids are called phosphatides.
• An example of phospholipids is lecithin, which is a good emulsifying agent and has an important role in the metabolism in the liver.

Steroids

• Steroids are also called sterols.
• Characterized by four linked carbon rings, three cyclohexane rings, and one cyclopentane ring.
• The functional group attached to the rings differs from sterol to sterol.
• The steroid nucleus is found in the structure of many vitamins, hormones, drugs, poisons, bile acids, steroids, and alcohol.
• Cholesterol is an example of a sterol.
  • Wax-like and found in animal-source foods.
  • Also found in brain tissue, nerve tissue, and blood.
  • Combination of steroids and alcohol, synthesized in the liver.
  • Major substance found in gallstone.
  • Contributed to the formation if lipid deposits on the inner walls of blood vessels which harden them and block blood flow.
• Testosterone is also a sterol.
  • Promotes the normal development of male genitals and secondary sexual attributes.
  • Synthesized from cholesterol in the testes.

Prostaglandins

• Prostaglandins are unsaturated carboxylic acids that are biochemically synthesized from the fatty acid arachidonic acid.
• Composed of 20 carbons and a five-member ring.
• Resemble the effects of hormones and are important biological agents.
• Carry out messages that the cells receive from hormones.
• Produces fever and inflammatory reactions and can be suppressed by aspirin.
• They are produced when tissues are damaged and are used to minimize the destruction of tissues.
• Some functions are to Stimulate the constriction of damaged blood vessels and blood clotting, induce labor and reproductive processes, inhibit acid synthesis in the gastrointestinal tract and secretion of protective mucus, and increase blood flow to the kidneys and promote constrictions of bronchi associated with asthma.

Proteins

• Proteins Comes from the Greek word Proteios which means first importance.
• Made up of carbon, hydrogen, oxygen, nitrogen, and sulfur.
• Found in all living cells.
• Second most common molecule in the human body.
• Makes up 10-20% of a cell.
• When digested, they are broken down into amino acids.
  • Contains a carboxyl group and an amino group (Amino acids with an Amino group bonded to the alpha carbon are called alpha amino acids).
  • Every alpha amino acid has carbon atoms called alpha carbon bonded to a carboxylic acid, amino, and hydrogen atom.
  • If two amino acids are joined together, a peptide is born that gives the product named dipeptide.
  • Peptides are formed when the carboxyl group of an amino acid reacts with an amino group.
• Body needs 20 amino acids to function known as essential amino acids and non-essential are ones that are produced by the body.

Nucleic Acids

• Nucleic acids are large biomolecules made by living organisms.
• Made up of nucleotides.
• Consisting of a carbohydrate molecule, a phosphate group, and a nitrogen-based molecule (either pyrimidine or purine).
• Nucleotides are made up of carbon, hydrogen, oxygen, nitrogen, and phosphorus.

DNA

• DNA' full name is deoxyribose Nucleic Acid.
• It is the genetic material of the cell and stores genetic information.
• A long chain polymer.
• DNA molecules in a single human cell are 2 meters long.

RNA

• The full name is ribonucleic Acid.
• Copies certain parts of DNA when proteins are needed.
• A pathway to create proteins whereby the info copied from DNA directs the order of amino acids to be bonded.

Function of Proteins

• The movement of muscles is made up of proteins called myosin and actin, which are responsible for muscle contraction.
• Structure: the proteins Keratin and Collagen are important structural components.
• Protection: Serves as antibodies against foreign substances called antigens, and a protein named fibrinogen also serves to stop bleeding (blood clotting).
• Hormones: many hormones come from proteins, and Insulin hormonal protein also regulates blood sugar.
• Transport: Transports molecules across cell membranes like hemoglobin, which carries oxygen from the lungs to the cells and carbon dioxide from the cells to the lungs.