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The Structure and Function of Macromolecules

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Presentation on theme: "The Structure and Function of Macromolecules"— Presentation transcript:

1 The Structure and Function of Macromolecules

2 Macromolecules - larger molecules made from smaller ones.
4 major classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids. 3 of these are polymers because they are made from individual building blocks called monomers.

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4 Monomers - joined together through condensation or dehydration reaction (form macromolecules)
Requires energy; uses covalent bonds (links together monomers) Water produced.

5 Water produced as by-product

6 Hydrolysis breaks polymers into monomers.
Water added to polymer; breaks bonds, creates monomers (i.e. digestive process in animals)

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8 Carbohydrates 1Carbohydrates - sugars (monomers) and polymers.
AMonosaccharides - simple sugars. BDisaccharides - double sugars (monosaccharides linked together) CPolysaccharides - polymers of monosaccharides. Sugars named with –ose.

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10 Monosaccharides needed for cellular work.
Help to synthesize other macromolecules.

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12 Maltose - 2 glucose molecules.
Sucrose - 1 glucose, 1 fructose.

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14 Polysaccharides - energy storage.
Starch - energy storage polysaccharide for plants. Cellulose – polysaccharide; plant cell walls. Animals store energy as glycogen.

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17 Chitin - polysaccharide - makes up exoskeleton of arthropods (like crustaceans and our sowbugs!).

18 Chitin is used in surgery

19 Lipids - no polymers (exception)
Lipids nonpolar (no affinity for water) Fat made from glycerol and fatty acids.

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21 Saturated fatty acid - No carbon-carbon double bonds in carbohydrate chain. (hydrogen at every possible position) Form bad fats - solid at room temperature (butter, lard)

22 No double-double bonds

23 unsaturated fatty acid - 1+ carbon-carbon double bonds.
Formed by removal of hydrogen atoms from carbon skeleton. Form good fats - liquid at room temperature (oils)

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25 Purpose of fat - energy storage.
Gram of fat stores 2X as much energy as gram of polysaccharide. Fat also cushions vital organs. Layer of fat can also function as insulation.

26 http://www. healthline

27 MOST IMPORTANT LIPID IN BIOLOGY = Phospholipid
Phospholipids have 2 fatty acids attached to glycerol. Fatty acid tails are hydrophobic, phosphate group and attachments form hydrophilic head.

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29 When phospholipids added to water, self-assemble with hydrophobic tails pointing toward center, hydrophilic heads on outside. Phospholipids in cell form bilayer; major component of cell membrane.

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31 Hydrophilic Hydrophobic

32 Other Lipids Steroids - lipids with carbon skeleton consisting of 4 fused carbon rings. Cholesterol - component in animal cell membranes and hormones.

33 Cholesterol

34 Proteins - support, storage, transport, defenses, and enzymes.
Made in ribosomes in cell. Proteins - amino acids linked together to form polymer. 20 different amino acids that can be linked together to form thousands of different proteins.

35 http://images. foodnetwork

36 Amino acids link - polypeptides - combine to form proteins.
Amino acids made of hydrogen atom, carboxyl group, amino group, variable R group (or side chain). R group makes amino acids different from one another.

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38 Shape of protein determines function.
Shapes - 3 dimensional - determined by sequence of amino acids.

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40 Primary structure of protein - linear sequence of amino acids determined by genetics.

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43 Secondary structure - two shapes are usually formed: alpha coils or beta sheets.

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45 Tertiary structure determined by interactions among R groups.

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47 Quarternary structure - joining of 2+ polypeptide subunits.
Collagen and hemoglobin examples.

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50 Protein’s shape can change due to environment.
pH, temperature, or salinity (salt concentrations) change - protein can denature (starts to fall apart) Some proteins can return to functional shape after denaturation, others cannot.

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52 Nucleic acids Amino acid sequence of polypeptide programmed by a gene.
2 types of nucleic acids: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).

53 http://www. uic. edu/classes/bios/bios100/lecturesf04am/nucleotides

54 DNA gives information so RNA can create proteins.
Flow of genetic information - DNA -> RNA -> protein. Protein synthesis occurs in ribosomes.

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56 Monomers of nucleic acids - nucleotides.
Nucleotides made up of 3 parts: nitrogen base, five-carbon sugar, and phosphate group. Nitrogen bases, rings of carbon and nitrogen, come in 2 types: purines and pyrimidines.

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58 Pyrimidines - cytosine (C), thymine (T), and uracil (U in RNA only).
Purines - adenine (A) and guanine (G). Pyrimidines - single six-membered ring; purines - five-membered ring.

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60 In RNA - sugar is ribose; DNA - sugar is deoxyribose.
Difference between sugars is lack of oxygen atom in deoxyribose.

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62 RNA single-stranded - linear shape.
DNA forms double helix. Sugar and phosphate forms backbone of double helix while nitrogen bases form connection between backbones.

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64 Adenine (A) always pairs with thymine (T) guanine (G) with cytosine (C).
Due to six and five membered rings – shapes are compatible. Two strands are complementary.

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66 DNA used to show evolutionary similarities between species.
Two species that appear to be closely-related based on fossil and molecular evidence also more similar in DNA and protein sequences than more distantly related species.

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