Biochemistry-of-Cells.pdf

Biochemistry of Cells Copyright Cmassengale 1 Functional Groups are: Groups of atoms that give properties to the compounds to which they attach Copyright Cmassengale 2 Common Functional Groups Copyright Cmassengale 3 Giant Molecules - Polymers Large m...

Biochemistry of Cells Copyright Cmassengale 1 Functional Groups are: Groups of atoms that give properties to the compounds to which they attach Copyright Cmassengale 2 Common Functional Groups Copyright Cmassengale 3 Giant Molecules - Polymers Large molecules are called polymers Polymers are built from smaller molecules called monomers Biologists call them macromolecules Copyright Cmassengale 4 Examples of Polymers Proteins Lipids Carbohydrates Nucleic Acids Copyright Cmassengale 5 Most Macromolecules are Polymers Polymers are made by stringing together many smaller molecules called monomers Nucleic Acid Monomer Copyright Cmassengale 6 Linking Monomers Cells link monomers by a process called condensation or dehydration synthesis (removing a molecule of water) Remove H2 H O For ms Remove OH This process joins two sugar monomers to make a double sugar Copyright Cmassengale 7 Breaking Down Polymers Cells break down macromolecules by a process called hydrolysis (adding a molecule of water) Water added to split a double sugar Copyright Cmassengale 8 Macromolecules in Organisms There are four categories of large molecules in cells: Carbohydrates Lipids Proteins Nucleic Acids Copyright Cmassengale 9 Carbohydrates Carbohydrates include: Small sugar molecules in soft drinks Long starch molecules in pasta and potatoes Copyright Cmassengale 10  Monosaccharides: Called simple sugars Include glucose, fructose, & galactose Have the same chemical, but different structural formulas C6H12O6 GLU-FRU-GAL Copyright Cmassengale 11 Monosaccharides Glucose is found in sports drinks Fructose is found in fruits Honey contains both glucose & fructose Galactose is called “milk sugar” -OSE ending means SUGAR Copyright Cmassengale 12 Isomers Glucose & fructose are isomers because their structures are different, but their chemical formulas are the same Copyright Cmassengale 13 Rings In aqueous (watery) solutions, monosaccharides form ring structures Copyright Cmassengale 14 Cellular Fuel Monosaccharides are the main fuel that cells use for cellular work ATP Copyright Cmassengale 15 Disaccharides A disaccharide is a double sugar They’re made by joining two monosaccharides Involves removing a water molecule (condensation) Bond called a GLYCOSIDIC bond Copyright Cmassengale 16 Disaccharides Common disaccharides include: Sucrose (table sugar) Lactose (Milk Sugar) Copyright Cmassengale 17 Disaccharides Sucrose is composed of glucose + fructose Maltose is composed of 2 glucose molecules Lactose is made of galactose + glucose GLUCOSE Copyright Cmassengale 18 Polysaccharides Complex carbohydrates Composed of many sugar monomers linked together Polymers of monosaccharide chains Copyright Cmassengale 19 Examples of Polysaccharides Glucose Monomer Starch Glycogen Cellulose Copyright Cmassengale 20 Starch Starch is an example of a polysaccharide in plants Plant cells store starch for energy Potatoes and grains are major sources of starch in the human diet Copyright Cmassengale 21  Glycogen Glycogen is an example of a polysaccharide in animals Animals store excess sugar in the form of glycogen Glycogen is similar in structure to starch because BOTH are made of glucose monomers Copyright Cmassengale 22 Cellulose Cellulose is the most abundant organic compound on Earth It forms cable-like fibrils in the tough walls that enclose plants It is a major component of wood It is also known as dietary fiber Copyright Cmassengale 23 Sugars in Water Simple sugars and double sugars dissolve readily in water WATER MOLECULE They are hydrophilic, or “water-lovin g” -OH groups SUGAR make them MOLECULE water soluble Copyright Cmassengale 24 Lipids Lipids are hydrophobic –”water fearing” Do NOT mix with water Includes fats, waxes, steroids, & oils FAT MOLECULE Copyright Cmassengale 25 Types of Fatty Acids Saturated fatty acids have the maximum number of hydrogens bonded to the carbons (all single bonds between carbons) Unsaturated fatty acids have less than the maximum number of hydrogens bonded to the carbons (a double bond between carbons) Copyright Cmassengale 26 Types of Fatty Acids Single Bonds in Carbon chain Double bond in carbon chain Copyright Cmassengale 27 Triglyceride Monomer of lipids Composed of Glycerol & 3 fatty acid chains Glycerol forms the “backbone” of the fat Organic Alcohol (-OL ending) Copyright Cmassengale 28 Fats in Organisms Most animal fats have a high proportion of saturated fatty acids & exist as solids at room temperature (butter, margarine, shortening) Copyright Cmassengale 29 Fats in Organisms Most plant oils tend to be low in saturated fatty acids & exist as liquids at room temperature (oils) Copyright Cmassengale 30  Lipids & Cell Membranes Cell membranes are made of lipids called phospholipids Phospholipids have a head that is polar & attract water (hydrophilic) Phospholipids also have 2 tails that are nonpolar and do not attract water Copyright Cmassengale 31  Steroids The carbon skeleton of steroids is bent to form 4 fused Cholesterol rings Cholesterol is the “base Estrogen steroid” from Testosterone which your body produces other steroids Estrogen & testosterone are also steroids Copyright Cmassengale 32 Synthetic Anabolic Steroids They are variants of testosterone Some athletes use them to build up their muscles quickly They can pose serious health risks APED - Appearance and Performance Enhancing Drugs Copyright Cmassengale 33 Proteins Proteins are polymers made of monomers called amino acids All proteins are made of 20 different amino acids linked in different orders Proteins are used to build cells, act as hormones & enzymes, and do much of the work in a cell Copyright Cmassengale 34 20 Amino Acid Monomers Copyright Cmassengale 35  Structure of Amino Acids Amino Carboxyl Amino acids have a group group central carbon with 4 things boded to R group it: Amino group –NH2 Carboxyl group -COOH Hydrogen -H Side groups Side group -R Serine-hydrophillic Leucine -hydrophobic Copyright Cmassengale 36 Linking Amino Acids Carboxyl Cells link amino acids together to Amino make proteins Side Group The process is called condensation or Dehydration dehydration Synthesis Peptide bonds form to hold the amino acids together Peptide Bond Copyright Cmassengale 37 Proteins as Enzymes Many proteins act as biological catalysts or enzymes Thousands of different enzymes exist in the body Enzymes control the rate of chemical reactions by weakening bonds, thus lowering the amount of activation energy needed for the reaction Copyright Cmassengale 38 Enzymes Enzymes are globular proteins. Their folded conformation creates an area known as the active site. The nature and arrangement of amino acids in the active site make it specific for only one type of substrate. Copyright Cmassengale 39 Enzyme + Substrate = Product Copyright Cmassengale 40 How the Enzyme Works Enzymes are reusable!!! Active site changes SHAPE Called INDUCED FIT Copyright Cmassengale 41 Primary Protein Structure The primary structure is the specific sequence of amino acids in a protein Called polypeptide Amino Acid Copyright Cmassengale 42 Denaturating Proteins Changes in temperature & pH can denature (unfold) a protein so it no longer works Cooking denatures protein in eggs Milk protein separates into curds & whey when it denatures Copyright Cmassengale 43 Changing Amino Acid Sequence Substitution of one amino acid for another in hemoglobin causes sickle-cell disease 2 7... 146 1 3 6 4 5 (a) Normal red blood cell Normal hemoglobin 2 7... 146 1 3 6 4 5 (b) Sickled red blood cell Sickle-cell hemoglobin Copyright Cmassengale 44  Other Important Proteins Blood sugar level is controlled by a protein called insulin Insulin causes the liver to uptake and store excess sugar as Glycogen The cell membrane also contains proteins Copyright Cmassengale 45 INSULIN Cell membrane with proteins & phospholipids Copyright Cmassengale 46 Nucleic Acids Store hereditary information Contain information for making all the body’s proteins Two types exist --- DNA & RNA Copyright Cmassengale 47 Copyright Cmassengale 48 Nucleic Acids Nitrogenous base (A,G,C, or T) Nucleic acids are Phosphate Thymine (T) polymers of group nucleotides Sugar (deoxyribose) Phosphate Base Sugar Nucleotide Copyright Cmassengale 49 Nucleotide – Nucleic acid monomer Copyright Cmassengale 50 Bases Each DNA nucleotide has one of the following bases: Thymine (T) Cytosine (C) –Adenine (A) –Guanine (G) –Thymine (T) –Cytosine (C) Adenine (A) Guanine (G) Copyright Cmassengale 51 Nucleotide Monomers Backbone Form long chains Nucleotide called DNA Nucleotides are joined by sugars & phosphates on the side Bases DNA strand Copyright Cmassengale 52 DNA Two strands of DNA join together to form a double helix Base pair Double helix Copyright Cmassengale 53 Copyright Cmassengale 54 RNA – Ribonucleic Acid Nitrogenous base (A,G,C, or U) Ribose sugar has an extra –OH or hydroxyl group Uracil Phosphate It has the group base uracil (U) instead of thymine (T) Sugar (ribose) Copyright Cmassengale 55  ATP – Cellular Energy ATP is used by cells for energy Adenosine triphosphate Made of a nucleotide with 3 phosphate groups Copyright Cmassengale 56 Copyright Cmassengale 57  ATP – Cellular Energy Energy is stored in the chemical bonds of ATP The last 2 phosphate bonds are HIGH ENERGY Breaking the last phosphate bond releases energy for cellular work and produces ADP and a free phosphate Copyright Cmassengale 58 Copyright Cmassengale 59 Summary of Key Concepts Copyright Cmassengale 60 Macromolecules Copyright Cmassengale 61 Macromolecules Copyright Cmassengale 62  End Copyright Cmassengale 63