BIO 100 Ch 3 Lecture PowerPoint.pptx

Essentials of Biology Sylvia S. Mader Michael Windelspecht Chapter 3 The Organic Molecules of Life Objectives List the four main groups of biochemical compounds; provide examples of each and describe their structure and function. Describe how bio...

Essentials of Biology Sylvia S. Mader Michael Windelspecht Chapter 3 The Organic Molecules of Life Objectives List the four main groups of biochemical compounds; provide examples of each and describe their structure and function. Describe how biochemical compounds are made and broken down (names of the reactions). 3-1  3.1 Organic Molecules The variety and functions of organic molecules makes life diverse. Organic molecules (aka biomolecules) contain carbon and hydrogen Carbohydrates Lipids Proteins Nucleic acids Inorganic molecules do not contain C and H, such as H2O and NaCl Figure 3.1 3-2 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  The Chemistry of Carbon Makes Diverse Molecules Possible Carbon atom Total of 6 electrons 4 in valence shell (outermost shell) Can bond with as many as 4 other elements Almost always shares electrons with C, H, N, O, P, S Most often shares electrons with other C atoms Hydrocarbons—chains of carbon atoms bonded only to hydrogen atoms Highly varied, forms branches or rings Hydrophobic Found in plants, fossil fuels, industrial processes Our bodies can't break these down (PCB, DDT) 3-3 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Figure 3.2  Carbon Skeleton and Functional Groups A carbon chain of a biomolecule is called the skeleton or backbone.​ Functional group—specific combination of bonded atoms that always has the same chemical properties and always reacts the same way Reactivity of organic molecule largely dependent on attached functional group Often use R to stand for the rest of the molecule​ 3-4 4 Figure 3.3 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Isomers Biomolecules with the same molecular formulas but a different arrangement of atoms Ex: Glucose & Fructose (C6H1206) Structure dictates function, so each structure will react differently 5  3.2 The Biological Molecules of Cells Molecular subunits can be linked to form varied large biomolecules Food is rich in biomolecules Carbohydrates, lipids, proteins, and nucleic acids Digestion breaks polymers (poly, many) down into monomers (mono, one), which are molecular subunits. 3-6 Figure Copyright © McGraw-Hill Education. All rights reserved. Authorized only3.5 Figureor3.10 for instructor use in the classroom. No reproduction distribution without the prior writtenFigure consent of 3.16 McGraw-Hill Education.  Biomolecules Dehydration synthesis Hydrolysis (lysis-break) reaction reaction Joins monomers to form Breaks polymers into polymers by removing water monomers by adding water 3-7 Figure 3.4 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Review What is the term called that means “to break?” 3-8 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Carbohydrates (CH2O) Almost universally used as immediate energy source in living things Play structural roles (ex. plants & fungi) Classified by number of saccharide, or sugar, units Monosaccharide Disaccharide Polysaccharide 3-9 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Monosaccharides (aka Simple Sugars) Single sugar molecule (monomer) Building blocks for bigger molecules 𝐂𝟔𝐇𝟏𝟐𝐎𝟔 Glucose 2 isomers - fructose, galactose Cells use glucose as the energy source of choice. Figure 3.6 Ribose and deoxyribose are found in RNA and DNA. 3-10 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Disaccharides 2 monosaccharides bonded together by dehydration reaction Maltose – to make beer, yeast breaks down maltose for energy (fermentation) Ethyl alcohol is a waste product Sucrose – table sugar from sugarcane and sugar beets Lactose – found in milk Figure 3.7 3-11 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Polysaccharides (Energy Storage) Complex carbs are polymers of many monosaccharides bonded together Some are used for short-term energy storage Animals store glucose as glycogen. Plants store glucose as starch. Figure 3.8 Some are used for structure Cellulose - plant cell walls Chitin - crab, lobster, insect exoskeletons, fungi 3-12 Peptidoglycan - bacteria Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Figure 3.9 Review True or False Cells use carbohydrates as an immediate source of energy. 3-13 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Lipids – Long-Term Energy Storage All are insoluble in water and hydrophobic Long nonpolar hydrocarbon chains Very diverse structures and functions Fats (solid at room temp.) and oils (liquid at room temp.) Animals have fat for insulation, cushioning internal organs, and for long-term energy storage Animals have oil glands to waterproof skin, hair, and feathers Plants use oils for long-term energy storage 3-14 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Triglycerides Most common lipid in your body (found in bloodstream and fat cells) Triglycerides: 1 glycerol (alcohol sugar) and 3 fatty acids Fatty acids are either: Figure 3.11 Saturated: no double bonds between C atoms (full of H bonds) Promotes LDL (bad) cholesterol Unsaturated: one or more double bonds between C atoms (missing 2 or more H atoms) Promotes HDL (good) cholesterol Trans fats: unsaturated fat processed to be more “solid”, aka “partially- hydrogenated oils” 3-15 Figure 3.12 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Lipids in Cells Phospholipids Forms 2-layered plasma membranes, aka “phospholipid bilayer” Consists of: Hydrophilic (likes water) phosphate head Polar, water-soluble Hydrophobic (hates water) fatty acid tails Non-polar, not water-soluble Figure 3.13 3-16 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Steroids Lipids made of 4 fused rings No fatty acids but are insoluble in water Derived from cholesterol Differ only in functional groups, but testosterone and estrogen have different effects 3-17 FigureCopyright 3.14© McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Review True or False Lipids include: - fats - triglycerides - cholesterol 3-18 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Proteins Proteins are composed of amino acid monomers 50% of dry weight of most cells Perhaps the most versatile biomolecule Cell structure and function are based on type of protein they contain: Support – keratin in hair & fingernails, collagen in skin, ligaments & tendons, protein in spiderwebs Metabolism – enzymes speed up chemical reactions Transport – hemoglobin transports O2 in blood Defense – antibodies attack foreign substances Regulation – intercellular messenger hormones, like insulin and human growth 3-19 hormone (hGH) Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Amino Acids & Peptides Amino acids (monomers) - building blocks of proteins 20 different amino acids Peptides (polymers) - two or more amino acids covalently linked by dehydration synthesis reaction Figure 3.17 Polypeptide - chain of many amino acids joined by peptide bonds Amino acid sequence determines the final three-dimensional shape of protein 3-20 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Shape of Proteins The shape of a protein determines its function Denaturation – irreversible change of protein shape caused by: heat pH or chemicals Loses its biological function. Cooking food denaturizes proteins Can help in digestion or nutrient acquisition 3-21 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Four Levels of Protein Organization Primary structure—amino acid sequence Secondary structure—portions of chain form helices or pleated sheets Tertiary structure—overall three-dimensional (globular) shape of interacting secondary structures Quaternary structure—more than one polypeptide chain interacting 3-22 Figure 3.19 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Nucleic Acids – Information Molecules Nucleotides (monomers) make up: nucleic acids (polymers) such as DNA & RNA. Deoxyribonucleic acid (DNA) Stores genetic information AKA blueprint of the cell Figure 3.20a Ribonucleic acid (RNA) Helps to make proteins 3-23 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Contain the sugar deoxyribose Structur Double helix (double stranded) e of Sugar & phosphate molecules make up DNA sides of ladder Complementary paired bases make up rungs Held together by… Complementary baseH pairing: bonds! Adenine (A) with thymine (T) Cytosine (C) with guanine (G) Genetic information stored in sequence of bases Figure 3.20b Base sequence of all the genes is called the genome. 3-24 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  RNA Bases Genetic information flows from DNA to RNA to proteins RNA is synthesized from a gene (DNA) Contains the sugar ribose Single-stranded Uracil (U) pairs with adenine (A) instead of thymine (T) Messenger RNA (mRNA) is a copy of the gene Important in protein synthesis – sequence Figure 3.21 of bases in mRNA determines sequence of Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 3-25  Comparing Proteins and Nucleic Acids Relationship between proteins and nucleic acids Sequence of bases in DNA determines sequence of amino acids in a protein. Sequence of amino acids determines a protein's structure and function. Small changes in the DNA may cause large changes in a protein. Sickle-cell disease Individual’s red blood cells are sickle-shaped One amino acid difference Inherited disease 3-26 Figure 3.22 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education. ATP: An Energy Molecule Adenosine Triphosphate (ATP) Composed of adenosine (adenine plus ribose) plus 3 phosphate groups High-energy molecule Hydrolyzed to form adenosine diphosphate (ADP) and a phosphate molecule Breakdown of ATP releases energy Animals Coupled to energy-requiring processes convert food ATP is the energy “currency” for all cells. energy to that of ATP 3-27 3-27 Copyright © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or distribution without the prior written consent of McGraw-Hill Education.