Biochemistry An Introduction to the Chemistry of Life for Biology Students

Organic Chemistry  Organic chemistry is the study of Carbon compounds.  Organic compounds are compounds composed primarily of a Carbon skeleton.  All living things are composed of organic compounds.

Organic Chemistry  What makes Carbon Special? Why is Carbon so different from all the other elements on the periodic table?  The answer derives from the ability of Carbon atoms to bond together to form long chains and rings.

Organic Chemistry

Carbon can form immensely diverse compounds, from simple to complex. Methane with 1 Carbon atom DNA with tens of Billions of Carbon atoms

Biochemistry  Biochemistry is a special branch of organic chemistry that deals with matter inside the living cell called Protoplasm.  Protoplasm is an enormously complex mixture of organic compounds where high levels of chemical activity occur.

Biochemistry 2. You will be expected to learn the basic biochemical processes of major cell functions, such as photosynthesis, respiration, and protein synthesis.  How much biochemistry do you need to know for this course?  1. You need to know the structure of organic molecules important to major biological processes.

Primary Organic Compounds 1.Carbohydrates 2.Lipids 3.Proteins 4.Nucleic Acids You are expected to learn the structure and functions of these organic compounds:

Polymers ands Monomers  Each of these types of molecules are polymers that are assembled from single units called monomers.  Each type of macromolecule is an assemblage of a different type of monomer.

Monomers MacromoleculeCarbohydratesLipidsProteins Nucleic acids MonomerMonosaccharide Not always polymers; Hydrocarbon chains Amino acids Nucleotides

How do monomers form polymers?  In condensation reactions (also called dehydration synthesis), a molecule of water is removed from two monomers as they are connected together.

Hydrolysis  In a reaction opposite to condensation, a water molecule can be added (along with the use of an enzyme) to split a polymer in two.

Carbohydrates  Carbohydrates are made of carbon, hydrogen, and oxygen atoms, always in a ratio of 1:2:1.  Carbohydrates are the key source of energy used by living things.  The building blocks of carbohydrates are sugars, such as glucose and fructose.

Carbohydrates  What do the roots mono-, di-, and poly mean?  Each of these roots can be added to the word saccharide to describe the type of carbohydrate you have.  

How do two monosaccharides combine to make a polysaccharide? 

Polysaccharides Polysaccharides

Lipids, also known as fats  The structure of a fat is that of a three- carbon glycerol molecule with up to three long chains of hydrogens and carbons called, hydrocarbons. The fatty acid tails are the long hydrocarbon chains. Lipids are NONpolar and do not dissolve in water.

What Are Fats?  Fats are important for your body because they insulate your nerve cells, balance your hormones, protect you from cold, keep the skin and arteries supple and also lubricate your joints. Fats contain a little more that twice as much energy as carbohydrates and proteins.  Humans store fat just below the skin to help insulate the body from cold weather and to store energy in case of famine. Some scientists believe that prehistoric humans often faced times of famine and may have evolved to crave fat.

Pure fats are found in three broad areas: vegetable oils (corn oil, peanut oil, olive oil and nuts), meats (the white layer which outlines the cut of meat), and dairy products (butter, margarine, mild and cheese). The type of fatty acids within each specific type of fat determines the character of the fat including how healthy it is. Carbon bonds determine the type of fatty acid.

Saturated vs. Unsaturated Fat  Carbon atoms are able to make chemical bonds with up to four other atoms. Each carbon in the fatty acid tail is bond to two other carbons, one in front of it and one behind it in the hydrocarbon chain. When a particular carbon is double- bonded to one of these carbons, it can only make one other bond to a hydrogen. When the carbon is single-bonded to the carbon on either side of it, it can make bonds with two hydrogen atoms. Saturated fats are bonded to as many H as possible, unsaturated fats have double carbon bonds so are not saturated with hydrogen.

Unsaturated Fats Unsaturated fats have double-bonded carbons, so each carbon can only bond to one hydrogen. These fats are “kinked” and cannot pack tightly. Unsaturated fatty acids remain liquid at room temperature. Unsaturated fats are considered good fats because of the lower cholesterol content. They usually come from plants sources, like olive oil.

Saturated Fats, the Bad Fats  Saturated fats, which do not have carbon-carbon bonds and so can pack tightly together, make a solid structure at room temperature. Avoid fatty meat because they are rich in saturated fat, which stimulates the production of cholesterol and can lead to clogged arteries (and a greater chance of a heart attack).

Hydrogenated Fats  If it needs to be solidified, it has to be hydrogenated, or saturated with hydrogen by breaking the carbon double bonds and attaching hydrogen. Commercial food manufacturers sometimes do this to retard spoilage and solidify liquid oils. Some of these manufactured fats are trans-fatty acids, common in fast foods. These fats are NOT healthy fats.

Saturated vs. Unsaturated  By virtue of their tightly packed structure, the saturated fatty acids increase the levels of bad cholesterol (LDL) and clog the arteries. On the other hand, the unsaturated fatty acids increase the levels of good cholesterol (HDL) by taking the LDL to the liver to be broken down and removed from the body.

Proteins  Proteins are building blocks of structures called amino acids. Proteins are what your DNA codes to make. A peptide bond forms between amino acids by dehydration synthesis.

Levels of Protein Structure 

Protein Structure LevelPrimarySecondaryTertiaryQuaternaryDescription The amino acid sequence Helices and Sheets Disulfide bridges Multiple polypeptides connect