Unit 3: Biochemistry Lesson 2- The Building Blocks of Life

Objectives A student should be able to … 1.Explain why carbon constitutes many biological macromolecules. 2.Know what elements comprise carbohydrates, lipids, proteins, and nucleic acids. 3.Name some examples of carbohydrates, lipids, proteins, and nucleic acids in living things. 4.Explain the functions of carbohydrates, lipids, proteins, and nucleic acids. 5.Demonstrate how indicators can be used to detect macromolecules in foods.

Organic Chemistry Organic chemistry –branch of chemistry that studies compounds containing carbon. organic compounds

Why is Carbon So Special? Four (4) valence electrons Can form up to four covalent bonds. Forms a wide variety of molecules –Straight chains –Branched chains –Rings Straight molecules Branched chain molecules Rings

Macromolecules Macromolecules are large molecules made by joining smaller molecules together. Macromolecules are examples of ___________. The _____________ are made up of smaller units called ______________ which are joined together by covalent bonds in a process called __________________. polymers monomers polymerization

Organic Macromolecules Four Groups of Organic Macromolecules Group name Chemical Composition Examples Function in Living Things Copy the following table into your notes and use it to take notes today.

Group Name: Carbohydrates Chemical composition: –carbon, hydrogen, and oxygen –General formula (CH 2 O) n Examples: –Monosaccharides – simple sugars galactose, glucose, fructose –Polysaccharides –longer carbohydrates composed of monosaccharides joined together glycogen, starch, chitin, cellulose Photo credit – Steven Berg

Function of Carbohydrates In Living Things Two main functions: Source of energy for living things –Glucose – ready energy –Glycogen (animals) and starch (plants) are energy storage molecules Structural molecules –Cellulose – support of cell walls in plants –Chitin – hard outer shell of shrimp, lobsters, some insects, and some fungi Monosaccharides Polysaccharides Give structure or Store energy

Group Name: Lipids Chemical composition: –largely of carbon and hydrogen –General structure: Triglyceride Three (3) fatty acids joined to a glycerol “backbone” Glycerol Fatty Acids

Chemical Composition: Saturated and Unsaturated Fats Saturated – all carbons are single bonded to one another Unsaturated - at least one carbon-carbon double bond exists in a fatty Polyunsaturated – more than one double bond exits

Examples of Lipids Triglycerides –Fat - solid at room temperature –Oil – liquid at room temperature Waxes Phospholipids Steroids

Function of Lipids in Living Things Fats & oils: -energy storage -insulation -buoyancy Waxes: -water repelancy -specialized structures (i.e. honeycomb) Phospholipids: -cell membranes Steroids: -Hormones – testosterone and adrenaline -Cholesterol

Group Name: Proteins Chemical composition: –composed of amino acids –amino acids contain hydrogen, carbon, oxygen, and nitrogen –amino acids are joined by peptide bonds Examples: –Bones, muscle, skin, tendons, ligaments, collagen, hair, blood,

Functions of Proteins 15% of your body mass Human body contains about 10,000 different kinds of proteins Functions: –Provide structural support (bones) –Allow movement (muscles) –Transport substances inside the cells and between cells –Communicate signals within/between cells –Speed up chemical reactions (enzymes) –Regulate cell growth –Defend against disease/foreign substances (antibodies) Hemoglobin

Protein Organization Proteins have up to four levels of organization or “structures.” Primary structure – sequence of amino acids in the protein chain. Secondary structure – amino acids in a chain can be twisted or folded Tertiary structure – twists or folds of a single protein chain Quaternary structure – the specific three- dimensional arrangement of multiple amino acid chains in space.

Group Name: Nucleic Acids Chemical composition: –composed of monomers called nucleotides –nucleotides contain hydrogen, carbon, oxygen, nitrogen, and phosphorus Examples: –DNA (deoxyribonucleic acid) –RNA (ribonucleic acid) –ATP (adenosine triphosphate) Function: –Store and transmit genetic information