Chapter 3: Biological Molecules

Explain how the primary structure of a protein is determined.

The sequence of amino acids. This sequence determines everything else about the protein's final shape.

List the 4 major components of an amino acid.

- Amino group - Carboxyl Group - Hydrogen Atom - R Group: determines qulaity (polar, nonpolar, etc.)

List the four major classes of molecules found in cells and the major functions of each.

- Carbohydrates (polysaccharides, monosaccharides, disaccharides) - Lipids (steroids, phospholipids, waxes) - Proteins (enzymes, hormones, contractile, glycoproteins) - Nucleic Acids (DNA & RNA)

List two types of nucleic acids.

- DNA - RNA

What bases in DNA pair up? and which bases in RNA pair up?

- DNA: Adenine and Thymine pair up and Guanine and Cytosine pair up. - RNA: Adenine pairs up with Uracil and Guanine and Cytosine pair up.

List 4 conditions under which protein can be denatured.

- Extreme heat - High or low pH - Ionization of liquid medium - A change in environment (The last one needs a little more explanation. If a protein is meant for a liquid-liquid environment, and it is brought into an air-liquid environment, it may denature. Proteins form because of the folds created from hydrophilic and hydrophobic folding. If there is no water in which these bonds form, the protein will denature.)

Be able recognize and provide some examples of functional groups?

- Groups of atoms known as functional groups can confer special properties on carbon-based molecules. - For example: the addition of an -OH group to a hydrocarbon molecule always results in the formation of an alcohol.

What are the four levels of protein structure and be able to describe how each structure forms.

- Primary structure: The sequence of amino acids (This sequence determines everything else about the protein's final shape.). - Secondary structure: Structural motifs, such as the corkscrew-like alpha helix, beta pleated sheets, and the less organized "random coils" are parts of many polypeptide chains, forming their secondary structure. - Tertiary structure: These motifs may persist through a set of larger-scale turns that make up the tertiary structure of the molecule. - Quaternary structure: Several polypeptide chains may be linked together in a given protein, in this case hemoglobin, with their configuration forming its quaternary structure.

Be able to list and describe the four main types of complex carbohydrates?

- Starch: is the nutrient storage form of carbohydrates in plants. - Glycogen: is the nutrient storage form of carbohydrates in animals. - Cellulose: is a rigid, structural carbohydrate found in the cells walls of many organisms. - Chitin: is a tough carbohydrate that forms the external skeleton of arthropods.

List the three types to a nucleotide.

- Sugar - Phosphate - Nitrogen base

Define a lipid, describe the structure and function of lipids. Know some specific examples of lipids.

- The defining characteristic of all lipids is that they do not readily dissolve in water. - Lipids do not possess the monomers-to-polymers structure seen in other biological molecules; no one structural element is common to all lipids. - Among the most important lipids are the triglycerides, composed of a glyceride and three fatty acids. - Most of the fats that human beings consume are triglycerides. - Examples of lipids are: Steroids, Phospholipids, and Waxes.

What is the difference between a lipoprotein vs. a glycoprotein.

A lipoprotein consists of a lipid and a protein, while a glycoprotein consists of a carbohydrate and a protein.

Briefly describe the differences between DNA and RNA.

DNA is present in the nucleus of all cells in all living organisms and controls all the chemical changes which take place in cells, while RNA is composed of ribose sugar and is present in all living cells.

Distinguish between monosaccharides, disaccharides, and polysaccharides.

Monosaccharides: Simple sugars (sugar molecules may be enantiomers due to the spatial arrangement of parts around asymmetric carbons; raw material for synthesis of other organic molecules.) Disaccharides: Two monosaccharides that are joined by a glycosidic linkage. Polysaccharides: Storage or structural macromolecules made from a few hundred to a few thousand monosaccharides.

What is the difference between Purines and Pyrimidines?

Purines contain two carbon-nitrogen rings and four nitrogen atoms, while Pyrimidines contain one carbon-nitrogen ring and two nitrogen atoms.

Name two types of secondary structure of a protein.

Structural motifs (such as the corkscrew-like alpha helix, beta pleated sheets) and the less organized "random coils" are parts of many polypeptide chains, forming their secondary structure.

Be able to explain what a peptide bond is.

a formation causing the amino acids to get strung together. The acid and amine ends of two amino acids come together to form an amide bond and give off a water molecule, resulting in the peptide bond.