Carbohydrates, Proteins, Lipids, Nucleic Acids Section 2 Chemistry of Cells Grade 10 Biology Fall 2010

Bell Ringer What do cooking oil, sugar, and a piece of meat have in common?

Objectives Summarize the characteristics of organic compounds Compare the structures and function of different types of biomolecules Describe the components of DNA and RNA State the main role of ATP in cells

Carbon Compounds Organic compounds contain carbon atoms that are covalently bonded to other elements Typically hydrogen, oxygen, and other carbon atoms Four principal classes of organic compounds are found in living things Carbohydrates, lipids, proteins, nucleic acids

Carbohydrates Carbohydrates: organic compounds made of carbon, hydrogen, and oxygen atoms in the proportion of 1:2:1 Key source of energy Monosaccharides: building blocks of carbs, single sugars Ex. Glucose C6H12O6, fructose Simple sugars such as glucose are a major energy source for cells

Carbohydrates Disaccharides: double sugars formed when two monosaccharides are joined Ex. Sucrose, consists of glucose and fructose Polysaccharides: chains of three or more monosaccharides Ex. Starch Example of a macromolecule, large molecule made of many smaller molecules Some function as storehouse of energy, starch and glycogen

Lipids Lipids: non-polar molecules that are not soluble or mostly insoluble in water Include fats, phospholipids, steroids, and waxes

Lipids Phospholipids make up the lipid bilayer of cell membranes Steroids include cholesterol, found in animal cell membranes

Lipids Fats are lipids that store energy Contains three fatty acids bonded to a glycerol molecule backbone Glycerol = 3-C organic molecule Fatty acid = long chain of C atoms, with H atoms bonded to them Most C atoms in a fatty acid are bonded to either one or two H atoms

Lipids Saturated fatty acid: all of the carbon atoms in the chain are bonded to two hydrogen atoms (except the carbon atoms on the end, which is bonded to three hydrogen atoms) Most animal fats are saturated Saturated fatty acids are relatively straight molecules and are generally solid at room temp.

Lipids Unsaturated fatty acid: some of the carbon atoms are linked by a “double” covalent bond, each with only one hydrogen atom, producing kinks in the molecule Most plant oils, some fish oils are unsaturated Unsaturated fatty acids generally liquid at room temp.

Lipids

Proteins Protein: usually a large molecule formed by linked smaller molecules called amino acids Amino acids: the building blocks of proteins Twenty different amino acids are found in proteins Amino acids can be: polar, non-polar, electrically charged, neutral

Proteins Proteins fold into compact shapes depending on how it’s A.A’s interact with water and one another Proteins are found in various areas and play important structural functions Some proteins are enzymes and promote chemical reactions

Nucleic Acids Nucleic acid: long chain of smaller molecules called nucleotides Nucleotide: has three parts a sugar, a base, and a phosphate group, which contains phosphorous and oxygen atoms Two types of nucleic acids- DNA and RNA- and each type contains 4 kinds of nucleotides

Nucleic Acids DNA: deoxyribonucleic acid, consists of two strands nucleotides that spiral around each other Chromosomes contain long strands of DNA, which store hereditary information

Nucleic Acids RNA: ribonucleic acid, may consist of a single strand of nucleotides or of based-paired nucleotides RNA plays key roles in protein manufacturing

ATP ATP: adenosine triphosphate, is a single nucleotide with two extra energy-storing phosphate groups When food molecules are broken down inside cells, some of the energy in the molecules is stored temporarily in ATP Cells need a steady supply of ATP to function

Review Name a difference and a similarity between RNA and DNA. Under the microscope the fat substitute that I spread on my toast has 4 double bonds, and 1 triple bond. Knowing this it must be what type of fatty acid? The main organic compound that is used as an energy source is?

Answers Difference is RNA is single strand, DNA is double stranded. Similarity they both have nitrogenous bases, sugar backbones, and phosphate groups. Unsaturated fatty acid. Carbohydrates.