Macromolecules of the cell

Macromolecules are built of repeating Units Macromolecules are all Polymers: large molecule formed when many smaller, but similar molecules, called monomers, bond together. Carbon is king! It is the main atom involved in building large (macro) molecules. Carbon can join with 4 other atoms to form chains, rings and branched molecules. There are a huge variety (shape and size) of carbon molecules…

Water Water is polar, i.e. each end of the molecule has a slight charge. This means that it is good at dissolving other (polar) molecules that also have a slight charge.

Water H 2 O is the key to making and breaking bonds in Biological Macromolecules.

Dehydration Synthesis Dehydration (aka a condensation reaction) loses water from the polymer and links monomers together. Energy is stored in the resulting bond.

Hydrolysis Hydrolysis adds water to the chemical bond that links monomers in macromolecules. This results in the breakdown of the polymer and the release of energy. + ENERGY (ATP)

Macromolecules and Nutrition Carbohydrates, Lipids, Proteins and Nucleic Acids are the “Big 4” macromolecules found in the human body and in foods. When you consume food your body breaks down the Polymers and the monomers are transported to your cells where they are built back into polymers useful to you.

Carbohydrates Monomers are called monosaccharides. Two monomers are called disaccharides Carbohydrate polymers are known as polysaccharides. All saccharides (or sugars) are used for energy and building structure in cells

Monosaccharides Are also known as simple sugars. They contain a single carbon ring Glucose, Galactose, and Fructose, for example, looks like this: Glucose (Fruit) Galactose Fructose (Honey)

Disaccharides Are composed of two (di) sugars (saccharides) (two carbon rings) Examples include: –Lactose (Milk) –Maltose –Sucrose (sugar)

Polysaccharides Polymers of three or more monosaccharides Arranged in chains and branches of carbon rings. Examples include:  Starch: Used by Plant cells for energy storage.  Glycogen: Glucose storage in Animals  Cellulose: Used by plant cells for structure (cellulose is like microscopic chicken wire).

Lipids Their bonds are very strong and contain a great deal of energy (used for energy storage). They are also used for structure and as molecular messengers (hormones) Fat monomers are made of glycerol and 3 fatty acid chains bonded together. They are insoluble in water because they are non-polar

Lipids Fats saturated Only single bonds in fatty acid Oils unsaturated fats Double bonds in fatty acids Both are long term energy storage

Proteins have many functions within a cell. Structure Primary building blocks of organisms Common Structural protein examples include: –Keratin (hair and nails) –Collagen (supports organs, plumps skin) Enzymes –regulate chemical reactions

Proteins Monomers of proteins are called “amino acids” There are 20 different common amino acids in proteins. Different chemical side chains on a common amino acid core determines which one of the 20 it is. Their sequence (order) within the protein polymer determines the protein shape and therefore it’s function.

Nucleic Acids They are used to code information that builds proteins which tells the cells how to work and what they will look like. There are two kinds; DNA and RNA The monomer is called a Nucleotide We will cover this in MUCH more detail in the following Units