1 Chemical Building Blocks of LifeBiochemistry Chemical Building Blocks of Life

2 Carbon Compounds and LifeAside from water, living organisms consist mostly of carbon-based compounds Carbon is unparalleled in its ability to form large, complex, and diverse molecules A compound containing carbon is said to be an organic compound © 2014 Pearson Education, Inc. 2

3 Carbon Bonding All compounds can be classified into 2 broad categoriesOrganic Compounds: are made primarily of carbon atoms Most matter in living organisms that is not water is made of organic compounds Inorganic Compounds: do not contain carbon atoms (with a few exceptions) Examples of organic compounds: wool, cotton, paper, potted plants

4 They have 4 valence electrons Carbon is so interesting…it could have a whole branch of chemistry by itself (2 Reasons) They have 4 valence electrons each e- can join with an e- from another atom to form a strong covalent compound Can bond with many elements including H, O, P, S, & N

5 2. They can bond to another carbon atom Carbon is so interesting…it could have a whole branch of chemistry by itself (2 Reasons) 2. They can bond to another carbon atom A. Gives the ability to form straight chains, branched chains, or rings B. These carbon-carbon bonds can be single, double, or triple covalent bonds C. Can share 2 or 3 e- No other element even comes close to matching carbon’s versatility

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7 Hydrocarbons Hydrocarbons are organic molecules consisting of only carbon and hydrogen Many organic molecules, such as fats, have hydrocarbon components Hydrocarbons can undergo reactions that release a large amount of energy © 2014 Pearson Education, Inc. 7

8 Hydrocarbons Hydrocarbons: made of only C & H-store a lot of energy (energy rich) Makes good fuels Hydrocarbons are nonpolar Propane gas is a hydrocarbon w/ 3 carbon atoms H H H Gasoline is rich in hydrocarbon H-C-C-C-H H H H

9 The Chemical Groups Most Important to LifeFunctional groups are the components of organic molecules that are most commonly involved in chemical reactions The number and arrangement of functional groups give each molecule its unique properties © 2014 Pearson Education, Inc. 9

10 Functional Groups Molecules can be thought of as a C-H coreEx: -OH can make molecules it is attached to polar. –OH is important to all living things Molecules can be thought of as a C-H core

11 Examples of functional groupA Carboxyl group (COOH) is alcohol with a hydroxyl group attached to one of its carbon atoms. The –OH makes alcohol a polar molecule A Hydrogen atom bonded with an Oxygen atom (-OH) called hydroxyl group

12 7 Functional groups that are important in the Chemistry of lifeHydroxyl group Carbonyl group Carboxyl group Amino group Sulfhydryl group Phosphate group Methyl group 12

13 The Primary Functional Chemical GroupsThese groups tend to act as units during reactions. Amino Acid Groups make molecules more basic Carboxyl Groups make molecules more acidic

14 Carbohydrates alcoholsFormaldehyde Amino Acids, Vinegar Ammonia Amino acids Proteins rubber Phospholipids ATP, nucleic acids

15 Macromolecules Many of the molecules in living cells are so large they are known as macromolecules which means “giant molecules”. They are made from thousands of smaller molecules

16 Macromolecules They are formed by a process known as polymerization where large compounds are built by joining smaller ones together

17 Macromolecules Made of small building blocks of molecules called monomers Monomers combine to form polymers A polymer consist of repeated units of monomers The units may be identical or structurally related to each other Large polymers are called macromolecules

18 Polymer is a long molecule build by linking together when many smaller molecules bond together {similar chemical subunits} Example: complex carbohydrates like starch are polymers

19 Building MacromoleculesMonomers link to form polymers by a chemical reaction known as condensation reaction. (also called dehydration synthesis) In condensation, the small molecules that are bonded together to make a polymer have an –H & -OH group that can be removed to form H-O-H. The subunits become bonded by a covalent bond

20 Dehydration Synthesis / Condensation Reaction

21 Breaking down polymersIn addition to building polymers by condensation reaction, living organisms have to break them down The breakdown of some complex molecules happens through hydrolysis reaction, Water is used to break down a polymer

22 Hydrolysis Hydrolysis is the reverse of a condensation reaction/dehydration synthesis The addition of water to some complex molecules (including polymers) under certain conditions can break the bonds that hold them together

23 Dehydration SynthesisHydrolysis

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26 How are macromolecules formed?Answer: Dehydration Synthesis It forms polymers by combining monomers by “removing water” HO H H2O HO H

27 How are macromolecules separated or digested?Answer: Hydrolysis Separates monomers by adding water HO H H2O HO H

28 4 Major Categories of Biological Macromolecules1. Carbohydrates 2. Proteins 3. Lipids 4. Nucleic Acids Sometimes these organic compounds are referred to as biomolecules These macromolecules are all polymers

29 1. CARBOHYDRATES

30 Carbohydrates Organic compounds made of C, H, & O in a ratio of 1C : 2H : 1O They serve as a source of energy Others used as structural material Monomers of monosaccharides (simple sugars)

31 3 Classes of CarbohydratesSmall sugar molecule  to Large sugar molecule Monosaccharides Disaccharides Polysaccharides

32 Monosaccharides A monomer of carbohydrate One sugar unit of C, H, & OGeneral Formula (CH2O)n where n is any whole number from 3 to 8

33 Monosaccharides Most common:1. Glucose (C6H12O6) made by plants during photosynthesis 2. Fructose (C6H12O6) found in fruits & is the sweetest 3. Galactose (C6H12O6) found in milk glucose

34 Isomers Glucose, fructose, and galactose have the same molecular formula but different structures Isomers are molecules that have the same molecular formula but different structures The different structures determine the different properties

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36 Disaccharides “Double Sugars”Two Sugar Units Sucrose=Glucose + Fructose (Table Sugar) (found in sugarcane and sugar beets) Maltose=Glucose + Glucose (Malt sugar) Lactose=Glucose + Galactose (milk sugar)(breast milk) glucose

37 Disaccharide Formula C6H12O6 + C6H12O6=C12H24O12 C12H22O11Dehydration Synthesis H2O C12H22O11 Are Disaccharides isomers?

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39 Polysaccharides “Many Sugars”Many sugar units (3 or more) Starch: storage from of sugar in plant Glycogen: animals store glucose in the form of glycogen -much of the glucose that comes from food is stored in your liver & muscle cells used as quick energy Cellulose: makes up plant cell walls -Chitin: form of cellulose; makes up the exoskeleton of insects & arthropods; fungi cell walls

40 glucose cellulose

41 PROTEINS

42 Proteins account for more than 50% of the dry mass of most cellsProteins include a diversity of structures, resulting in a wide range of functions Proteins account for more than 50% of the dry mass of most cells Protein functions include defense, storage, transport, cellular communication, movement, and structural support © 2014 Pearson Education, Inc. 42

43 Proteins perform the chemistry of the cellMade mostly of C, H, O, & N Formed from the linking of monomers called amino acids The proteins within living organisms are immensely diverse in structure & function Hair, horns, skin, muscles and many catalysts are mostly proteins There are 7 functions of proteins

44 7 Functions of Proteins 1. Enzyme catalysis: facilitate chemical reactions by stressing particular bonds 2. Defense: cell surface receptors that recognize foreign microbes Example: antibodies 3. Transport molecules & ions: Example-hemoglobin carries oxygen 4. Support: make up hair, nails, skin, ligaments, tendons, bones

45 7 Functions of Proteins 5. Motion: muscles contract through the sliding motion of 2 kinds of protein filaments Ex. Actin & myosin of muscles 6. Regulation: small proteins called hormones serve as intercellular messengers in animals. 7. Storage: calcium & iron are stored by binding into ions to specific storage proteins

46 Amino Acids: Monomers of ProteinsThere are only 20 amino acids, & all share a basic structure What makes one protein different from another? The order and arrangement of amino acids!

47 Amino Acid Structure An amino acid molecule contains:an amino group (-NH2) a carboxyl group (-COOH) a single Hydrogen Atom R-group (side chain)-what makes them different The remainder group is what makes one amino acid different from another.

48 The main difference amongAmino acids is their R group R-group can be simple or complex R-group gives different shapes Carboxyl (COOH) Amino (NH2) Hydrogen (H) R-Group *All bonded to carbon

49 The Peptide Bond A peptide bond is a covalent bond that links two amino acids to form a dipeptide Forms when the amino end of one amino acid joins the carboxyl end of another

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51 polypeptide Polypeptides are long chains of amino acidsThe amino acid sequence of the protein determines how each protein bends and folds on itself and how the protein intertwines.

52 Condensation reaction

53 Proteins consist of long amino acid chains folded into complex shapes.The Shape of a protein is very important because it determines the protein’s function. Proteins consist of long amino acid chains folded into complex shapes.

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55 Levels of Protein Structure1. Primary Structure: Order of amino acids (encoded in our genes) EX. Proline-glutamine-alanine If you put these in a different order you have a different protein aa1 aa2 aa3 aa4 aa5 aa6 Peptide Bonds Amino Acids (aa)

56 Levels of Protein Structure2. Secondary Structure: Hydrogen bonds form between amino acids arranged into spirals (coils) or pleated sheets Alpha Helix Beta Pleated Sheet Hydrogen Bonds

57 Levels of Protein Structure3. Tertiary Structure: The spiral or pleated sheets fold on themselves making a 3-D shape Alpha Helix Beta Pleated Sheet

58 Levels of Protein StructureQuaternary Structure: clustering of many proteins (2 or more polypeptide chains join to form a functional protein) Globular in shape Forms in aquatic environments Ex: hemoglobin subunits

59 What Determines Protein Structure?In addition to primary structure, physical and chemical conditions can affect structure Alterations in pH, salt concentration, temperature, or other environmental factors can cause a protein to unravel This loss of a protein’s native structure is called denaturation 59

60 Denaturation Protein shape can be influenced by conditions like temperature & solvents a protein is dissolved Ex: cooking an egg changes the shape of the proteins in the egg white Ex: Salt-curing & Pickling denatures the enzymes of microorganisms and keeps them from growing on food

61 LIPIDS

62 Lipids Lipids are large, nonpolar organic moleculesThey do not dissolve in water Include: triglycerides, phospholipids, steroids, waxes, fats, oils, hormones and pigments Stores the most energy Phospholipids make up cell membrane structure

63 Functions of Lipids Protects against water lossLong term energy storage Chemical messengers (hormones/steroids) Chemical defenses Protects against heat loss (insulation) Protects against physical shock

64 Fats Fats are constructed from two types of smaller molecules: glycerol and fatty acids Glycerol is a three-carbon alcohol with a hydroxyl group attached to each carbon A fatty acid consists of a carboxyl group attached to a long carbon skeleton © 2014 Pearson Education, Inc. 64

65 Fatty Acids Fatty Acids are unbranched carbon chains that make up most lipids Contain long C chain with a carboxyl group attached at one end COOH-Polar Carbon Chain-Non-polar

66 Plasma Membrane Found in the cell Hydrophilic head Hydrophobic tail

67 Saturated & Unsaturated fatty acidsSaturated Fatty Acids: each C-atom is covalently bonded to 4 atoms, each full or saturated Unsaturated Fatty Acids: has C-atoms that are not bonded to the maximum number of atoms they can bond with; instead they form double bonds within the carbon chain

68 Good fats Corn oil, olive oil

69 Bad fats Butter, Animal fat

70 Fats made from saturated fatty acids are called saturated fats and are solid at room temperatureMost animal fats are saturated Fats made from unsaturated fatty acids, called unsaturated fats or oils, are liquid at room temperature Plant fats and fish fats are usually unsaturated 70

71 The major function of fats is energy storage Fat is a compact way for animals to carry their energy stores with them © 2014 Pearson Education, Inc. 71

72 3 Classes of Lipids 3 classes of lipids; important to living things contain fatty acids 1. Triglycerides (fats) 2. Phospholipids 3. Waxes

73 1. Triglycerides Triglycerides have 3 fatty acids joined to one glycerol Saturated triglycerides: have high melting points & tend to be hard at room temperature (butter & fats in red meat) Unsaturated triglycerides: usually soft or liquid at room temperature (plant seeds where they serve as energy & C-source for germinating plants)

74 (b) Fat molecule (triacylglycerol)Figure 3.12b The synthesis and structure of a fat, or triacylglycerol (part 2: a triacylglycerol molecule) 74

75 2. Phospholipids Phospholipids have 2 fatty acids and a phosphate group attached to a molecule of glycerol The cell membrane is made of 2 layers of phospholipids called the lipid bilayer that forms a barrier between the inside and outside of the cell

76 Phospholipids are major constituents of cell membranesThe two fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head Phospholipids are major constituents of cell membranes © 2014 Pearson Education, Inc. 76

77 (a) Structural formula (b) Space-filling modelFigure 3.14ab Choline Phosphate Hydrophilic head Glycerol Fatty acids Hydrophobic tails Figure 3.14ab The structure of a phospholipid (part 1: formula and space-filling model) (a) Structural formula (b) Space-filling model 77

78 3. Waxes Waxes consist of a long fatty-acid chain joined to a long alcohol chain Are waterproof Form a protective coating on the outer surface of plants Form protective layers in animals (earwax)

79 NUCLEIC ACIDS

80 Nucleic acids store, transmit, and help express hereditary informationThe amino acid sequence of a polypeptide is programmed by a unit of inheritance called a gene Genes are made of DNA, a nucleic acid made of monomers called nucleotides Nucleic Acids store and transfer genetic information in the cell 80

81 The Roles of Nucleic AcidsThere are two types of nucleic acids Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) DNA provides directions for its own replication DNA directs synthesis of messenger RNA (mRNA) and, through mRNA, controls protein synthesis 81

82 The Components of Nucleic AcidsNucleic acids are polymers called polynucleotides Each polynucleotide is made of monomers called nucleotides Each nucleotide consists of a nitrogenous base, a pentose (5-carbon) sugar, and one or more phosphate groups The portion of a nucleotide without the phosphate group is called a nucleoside 82

83 3 Parts of a DNA nucleotide:5-Carbon Sugar (Deoxyribose) A Phosphate Group A nitrogen base (adenine, guanine, thymine or cytosine) A-T; T-A G-C; C-G

84 3 Parts of a RNA nucleotide:5 Carbon sugar (ribose) A phosphate group A Nitrogen base (adenine, uracil, guanine, cytosine) A-U; G-C

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88 The DNA Code The sequence of A,T,C,G (genes) (genes are on chromosomes) Code for amino acids which make up proteins for structures and enzymes Shape: double helix (twisted ladder) H bond holds nitrogen bases together Base pair rule: A-T, G-C

89 4 Main Difference between DNA & RNADNA double stranded RNA single stranded DNA has deoxyribose sugar RNA has ribose sugar DNA has thymine RNA has uracil DNA remains in the nucleus RNA carries the DNA code to a ribosome