Biochemistry: Monomers and Polymers Carbohydrates, lipids, proteins, and nucleic acids

Monomers Glucose Amino acids Nucleotides Fatty acids

Polymers Carbohydrates Nucleic acids Lipids Proteins

Carbohydrates The word carbohydrate literally means “watered carbon.” Do you remember the chemical formula for glucose? How does that remind us of the formula for water? C 6 H 12 O 6 4

Carbohydrate Definition Carbohydrates are molecules composed of carbon, hydrogen, and oxygen – they are polymers of glucose. – They are polysaccharides. Carbohydrates can be broken down to provide a source of usable chemical energy for cells. They are a major part of plant cell structure (our producers). 5

Carbohydrates: Cellulose, Starch, and Glycogen Cellulose is a rigid, straight polysaccharide, which makes up the cell walls of plants. – it is tough and fibrous (a good source of your fiber). Starch is a polysaccharide made and stored by plants. – It is broken down for energy by both plants and animals. Glycogen is a highly branched polysaccharide of glucose – It serves as a form of energy storage in animals and fungi. – The polysaccharide structure represents the main storage form of glucose in the body. 6

Lipids Lipids are nonpolar, uncharged, molecules that include fats, oils, and cholesterol. –Fats and oils are made up of fatty acids bonded together. –Fatty acids are the monomers for lipids. –Fatty acids are made up of carbon chains bonded with oxygen and hydrogen. 7

Lipid Functions Lipids have several different functions. They are: –broken down as a source of energy (triglycerides). –make up cell membranes (phospholipids) – used to make hormones (see structure below). 8

Fats and Oils Are Made Up of Triglycerides 9 Triglycerides are made when three fatty acids are attached to a glycerol molecule. Fats and oils are made up of fatty acids bound together as triglycerides. The fatty acids can be either saturated or unsaturated (see next slide). GlycerolFatty acid tails

Fatty Acids: Saturated and Unsaturated A saturated fatty acid has no C-C bonds. Unsaturated does. Olive oil is high in unsaturated fat while butter is very high in saturated fat. 10

11 The more the oil is unsaturated (has more carbon- carbon double bonds) the lower its melting temperature.

Lipids make cell membrane 12

Proteins Proteins are polymers of amino acid monomers – the polymers are created in the cell as part of DNA translation process. Twenty different amino acids are used to build proteins in organisms. 13

Def. of Amino Acid Amino acids are molecules that contain C, H, O, N, and sometimes sulfur. – Our bodies are able to make 12 of the 20 amino acids, the rest come from what you eat. – The amino acid monomers are linked together by peptide bonds to form protein polymers. 14

Amino acids give proteins shape Proteins differ in the number and order of amino acids. Amino acids interact to give a protein its shape, which determines its biological function(s). 15

Nucleic Acids Nucleic acids are polymers of monomers called nucleotides. Nucleotide – is composed of a sugar, a phosphate group, and a nitrogen containing molecule called a base (we will talk a lot more 2 nd semester about these). DNA and RNA are the two types of nucleic acids. 16

Example: Nucleotide Monomer A phosphate group nitrogen-containing molecule, called a base deoxyribose (sugar) 17

Nucleic Acids - Polymers This shows the two strands of DNA that connect, via hydrogen bonds, and twist to form a double helix. RNA is single stranded. 18

Nucleic Acids DNA stores genetic information. RNA builds proteins. DNA RNA 19

Entrance Ticket Name the monomers for these polymers: – Protein – Carbohydrate – Nucleic acid – Lipid 20