Copyright Cmassengale Biochemistry of Cells Copyright Cmassengale
Copyright Cmassengale Biochemistry All living things are composed of the following basic elements: Carbon Hydrogen aka “CHNOPS” Nitrogen Oxygen Phosphorous Sulfur A molecule containing carbon is called an ORGANIC MOLECULE Copyright Cmassengale
Uses of Organic Molecules Americans consume an average of 140 pounds of sugar/person/year Cellulose, found in plant cell walls, is the most abundant organic compound on Earth Copyright Cmassengale
Uses of Organic Molecules A typical cell in your body has about 2 meters of DNA A typical cow produces over 200 pounds of methane gas each year Copyright Cmassengale
Copyright Cmassengale Water About 60-90 percent of an organism is water Water is used in most reactions in the body Water is called the universal solvent Copyright Cmassengale
Carbon-based Molecules Although a cell is mostly water, the rest of the cell consists mostly of carbon-based molecules Organic chemistry is the study of carbon compounds Copyright Cmassengale
Copyright Cmassengale Hydrocarbons The simplest carbon compounds … Contain only carbon & hydrogen atoms Copyright Cmassengale
Carbon can use its bonds to:: Attach to other carbons Form an endless diversity of carbon structures Copyright Cmassengale
Large Hydrocarbons: Are the main molecules in the gasoline we burn in our cars The hydrocarbons of fat molecules provide energy for our bodies Copyright Cmassengale
Shape of Organic Molecules Each type of organic molecule has a unique three-dimensional shape The shape of the organic molecule determines its function in an organism Copyright Cmassengale
Giant Molecules - Polymers Large molecules are called polymers Polymers are built from smaller molecules called monomers or subunits Biologists call them macromolecules Copyright Cmassengale
Copyright Cmassengale Examples of Polymers Proteins Lipids Carbohydrates Nucleic Acids Copyright Cmassengale
Most Macromolecules are Polymers Polymers are made by stringing together many smaller molecules called monomers or subunits Nucleic Acid Monomer Copyright Cmassengale
Linking Monomers Cells link monomers by a process called condensation or dehydration synthesis (removing a molecule of water) Remove H H2O Forms Remove OH This process joins two sugar monomers to make a double sugar Copyright Cmassengale
Breaking Down Polymers Cells break down macromolecules by a process called hydrolysis (by adding a molecule of water) Water added to split a double sugar Copyright Cmassengale
Macromolecules in Organisms There are four categories of large molecules in cells: Carbohydrates Lipids Proteins Nucleic Acids Copyright Cmassengale
Carbohydrates Carbohydrates include: -Small sugar molecules in soft drinks -Long starch molecules in pasta and potatoes - Cellulose in plants Copyright Cmassengale
Copyright Cmassengale Provides ENERGY for organisms 4 calories/gram CHO in 1:2:1 ratio 3 types: 1. Monosaccharides 2. Disaccharide 3. Polysaccharide Monomer =monosaccharide Most end in - ose Copyright Cmassengale
Copyright Cmassengale Monosaccharides: Called simple sugars Include glucose, fructose, & galactose Have the same chemical formula, but different structural formulas C6H12O6 Copyright Cmassengale
-OSE ending means SUGAR Copyright Cmassengale 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
Rings In aqueous (watery) solutions, monosaccharides form ring structures Copyright Cmassengale
Copyright Cmassengale Cellular Fuel Monosaccharide (glucose) is the main fuel in living organism – must be converted into a form of energy that our cells can use (“ATP”) ATP Copyright Cmassengale
Copyright Cmassengale Disaccharides A disaccharide is a a double sugar They’re made by joining two monosaccharides Involves removing a water molecule (condensation or dehydration reaction) Copyright Cmassengale
Common disaccharides include: Copyright Cmassengale Sucrose (table sugar) Lactose (Milk Sugar) Maltose (Grain sugar) Copyright Cmassengale
Copyright Cmassengale Polysaccharides Complex carbohydrates Composed of many sugar monomers linked together Polymers of monosaccharide chains Copyright Cmassengale
Examples of Polysaccharides Glucose Monomer Starch – storage carbohydrate in plants Glycogen – storage carbohydrate in humans Cellulose – structural carbohydrate in plants Copyright Cmassengale
Copyright Cmassengale 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
Copyright Cmassengale 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 but linked differently Copyright Cmassengale
Copyright Cmassengale Cellulose Cellulose is the most abundant organic compound on Earth It forms the tough cell walls of plants which provide support It is a major component of wood It is also known as dietary fiber - humans cannot digest cellulose Copyright Cmassengale
Copyright Cmassengale Lipids Lipids are hydrophobic –”water fearing” Do NOT dissolve or mix with water = nonpolar Includes fats, waxes, steroids, oils chlorophyll & phospholipids Made of CHO FAT MOLECULE Copyright Cmassengale
Copyright Cmassengale Function of Lipids Fats store energy, help to insulate the body, and cushion and protect organs Fats provide 9 calories/gram Carbohydrates may be converted into lipids for long-term energy storage Copyright Cmassengale
Types of Lipids (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
Copyright Cmassengale Types of Fatty Acids Single Bonds in Carbon chain Double bond in carbon chain Copyright Cmassengale
Copyright Cmassengale Triglyceride Monomer (subunit) of lipids Composed of Glycerol & 3 fatty acid chains Glycerol forms the “backbone” of the fat Organic Alcohol (-OL ending) Copyright Cmassengale
Copyright Cmassengale Triglyceride Fatty Acid Chains Glycerol Copyright Cmassengale
Copyright Cmassengale 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
Copyright Cmassengale Fats in Organisms Most plant oils tend to be low in saturated fatty acids & exist as liquids at room temperature (oils) Copyright Cmassengale
Copyright Cmassengale Steroids The carbon skeleton of steroids is bent to form 4 fused rings Cholesterol Cholesterol is the “base steroid” from which your body produces other steroids Estrogen Testosterone Estrogen & testosterone are also steroids Copyright Cmassengale
Synthetic Anabolic Steroids They are variants of testosterone Some athletes use them to build up their muscles quickly They can pose serious health risks Copyright Cmassengale
Copyright Cmassengale Proteins Proteins are polymers made of monomers (subunits) 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
Structure of Amino Acids group Carboxyl group Amino acids have a central carbon with 4 things bonded to it: R group Amino group –NH2 Carboxyl group -COOH Hydrogen -H Side groups Side group -R Serine-hydrophillic Leucine -hydrophobic Copyright Cmassengale
Copyright Cmassengale Linking Amino Acids Carboxyl Cells link amino acids together to make proteins Amino Side Group The process is called condensation or dehydration Dehydration Synthesis Peptide bonds form to hold the amino acids together Peptide Bond Copyright Cmassengale
Copyright Cmassengale Four Types of Proteins Enzymes - promote chemical reactions Structural – such as collagen in skin, muscles, ligaments, tendons, bones. Antibodies (immune system) – help fight infection Hemoglobin – carries oxygen in blood Copyright Cmassengale
Copyright Cmassengale 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
Enzyme + Substrate = Product Copyright Cmassengale
Copyright Cmassengale How the Enzyme Works Enzymes are reusable!!! Active site changes SHAPE Called INDUCED FIT Copyright Cmassengale
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
Changing Amino Acid Sequence Substitution of one amino acid for another in hemoglobin causes sickle-cell disease 7. . . 146 2 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
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 Receptor proteins help cells recognize other cells Copyright Cmassengale
Cell membrane with proteins & phospholipids Copyright Cmassengale INSULIN Cell membrane with proteins & phospholipids Copyright Cmassengale
Copyright Cmassengale Nucleic Acids Store hereditary information Contain information for making all the body’s proteins Two types exist --- DNA & RNA Copyright Cmassengale
Copyright Cmassengale
Copyright Cmassengale Nucleic Acids Nitrogenous base (A,G,C, or T) Nucleic acids are polymers of nucleotides Phosphate group Thymine (T) Sugar (deoxyribose) Phosphate Base Sugar Nucleotide Copyright Cmassengale
Nucleotide – Nucleic acid monomer Copyright Cmassengale
Copyright Cmassengale Nucleic Acids Copyright Cmassengale
Copyright Cmassengale 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
Copyright Cmassengale Nucleotide Monomers Backbone Form long chains called DNA Nucleotide Nucleotides are joined by sugars & phosphates on the side Bases DNA strand Copyright Cmassengale
Copyright Cmassengale DNA Two strands of DNA join together to form a double helix Base pair Double helix Copyright Cmassengale
Copyright Cmassengale RNA – Ribonucleic Acid Nitrogenous base (A,G,C, or U) Ribose sugar has an extra –OH (or hydroxyl group) Uracil Phosphate group It has the base uracil (U) instead of thymine (T) Sugar (ribose) Copyright Cmassengale
Copyright Cmassengale ATP – Cellular Energy ATP is used by cells for energy Adenosine triphosphate Made of a nucleotide with 3 phosphate groups Copyright Cmassengale
Copyright Cmassengale 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 ADP (adenosine Diphosphate) can be rejoined to the free phosphate to make more ATP Copyright Cmassengale
Summary of Key Concepts Copyright Cmassengale
Copyright Cmassengale Macromolecules Copyright Cmassengale
Copyright Cmassengale Macromolecules Copyright Cmassengale
Copyright Cmassengale End Copyright Cmassengale