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Microbiology
Chemistry Principles
Question | Answer |
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What 4 things does the Knowledge of microorganism chemistry helps us understand? | •The role of microorganisms in nature •How they cause disease •How the body combats infection •How we can utilize microorganisms for our own benefit |
Define element. What is an element made of? | All matter is composed of elements: substances that cannot be broken down into simpler substances by ordinary chemical methods -Each element has its own name and 2 letter symbol |
What are the 4 Most abundant chemical compounds in living organisms? | •Most abundant chemical compounds in living organisms are : -Hydrogen -Carbon -Nitrogen -Oxygen |
What are the 3 particles that make up an atom? Where are they each found? What is their charge? | Proton(+), Neutron(O), Electron(-); protons and neutrons are found in the nucleus and the electrons are found in the electron shells. |
What is the overall electrical charge of an atom? | Electrically neutral; total positive charge of the nucleus equals the total negative charge of the electrons |
Define atomic number and atomic weight. | The atomic number: the number of protons in an atom’s nucleus (same as the number of electrons) The atomic weight: the total number of protons and neutrons in an atom |
What is the valence electron shell? Why are the electrons in this shell important? | Outermost electron shell is called the valence shell. Electrons in valence shell are involved in chemical reactions |
Why do atoms form bonds with other atoms? | Desire to have achieve stability of 8 electrons in valence shell = driving force behind chemical reactions |
Define molecule and compound. | Molecule: 2 or more atoms bonded together (ex: H2, O2) Compound: specific molecule that has 2 or more different kinds of atoms bonded together (ex: H2O) |
Define chemistry. | Chemistry is the study of interactions between atoms and molecules. |
Define chemical bond. | Chemical bonds: energy relationships between electrons of reacting atoms. |
What are the 3 types of chemical bonds? | 3 types of chemical bonds: 1) Ionic 2) covalent 3) hydrogen |
Describe ionic bonds and how they are made. | Ionic bonds involve the transfer of valence shell electrons from one atom to another, resulting in Ions. Attraction of opposite charges results in an ionic bond |
What are ions? | Ions: atoms that have gained or lost electrons and become charged |
Describe covalent bonds and how they are made. | Covalent bonds are formed by sharing of one or more pairs of electrons between two atoms Stronger than ionic bonds |
What is the difference between a single, double, and triple covalent bond? | •Single covalent bond: share one pair of electrons •Double covalent bond: share two pairs of electrons •Triple covalent bond: share three pairs of electrons |
What is the difference between nonpolar and polar covalent bonds? | A) Nonpolar covalent bonds Equal sharing of electrons Results in electrically balanced, nonpolar molecules B) Polar covalent bonds Results in electrically polar molecules Atoms have different electron-attracting abilities, leading to unequal sharing |
Describe hydrogen bonds? | Hydrogen bonds: an attractive force between electropositive hydrogen of one molecule and an electronegative atom of another molecule Not true bond, more of a weak magnetic attraction |
How are hydrogen bonds made? | Typically forms when a hydrogen atom that is covalently bonded to an O or N atom is attracted to another N or O atom in another molecule•Common in water |
Define inorganic compound. | Inorganic compounds typically lack carbon -Structurally simple -Ionic bonds play an important role -Include: water, O2, salts, acids, bases |
Describe water. | •Water is the most abundant inorganic compound •Vital to microorganisms •Makes up between 65%-75% of cell volumes on average •Water is a polar molecule, which gives it 4 characteristics that make it important for living cells |
What are the 4 properties of water that are important to living systems? (^) | 1) Water has a high boiling point and often exists in liquid state •Water forms hydrogen bonds with other water molecules•Need a lot of heat to separate water molecules from each other |
What are the 4 properties of water that are important to living systems? (solvent) | 2) Water is an excellent dissolving medium (solvent)•Substances held together with ionic bonds are separated in water |
What are the 4 properties of water that are important to living systems? (CR) | 3) water acts as the reactant or product in many chemical reactions |
What are the 4 properties of water that are important to living systems? (Temp) | 4) water is an excellent temperature buffer•More heat is necessary to raise the temperature or lower the temperature of water than to raise the temperature of a non-hydrogen bonded liquid |
Define organic compound. | Organic compounds always contain carbon and hydrogen -Held together mainly with covalent bonds -Can be very large -Include: polysaccharides, lipids, proteins, nucleic acids, and ATP |
What are macromolecules? | Small organic molecules combine into large molecules called macromolecules |
Define polymer and monomer. What is the relationship between monomers and polymers? | Macromolecules are usually polymers•polymers: a molecule consisting of similar molecules called monomers; Formed by covalent bonds Polymers are built through dehydration synthesis and broken down through hydrolysis |
Describe the process by which polymers are made. What is the name for this process? | Dehydration Synthesis. Combine and remove h2o Ex) Glucose+Fructose=Sucrose |
Describe the process by which polymers are broken down. What is the name for this process? | Hydrolysis. Separate with h2o Ex)Sucrose+water=Glucose+Fructose |
What are carbohydrates and what is their function? | Carbohydrates: large group of organic compounds that include sugars and starches -Contain C, H, and O -Function:Source of energy to fuel for cell activities |
What are the 3 classes of carbohydrates? | Three classes 1) Monosaccharides 2) Disaccharides 3) Polysaccharides |
How are carbohydrates formed? What is a glycosidic bond? | -OH group of one monomer joins with the –H group of another -Bond is called a glycosidic bond |
What are lipids? | Lipids contain C, H, O and sometimes contain P. -Are nonpolar ,so are insoluble in water |
What are the 3 types of lipids. | 1) Triglycerides (simple lipids, fats) 2) Phospholipids 3) Steroids |
Describe triglycerides. | -Contain an alcohol (glycerol) and a group of compounds called fatty acids -Glycerol has 3 carbon atoms attached to 3 hydroxyl (-OH) groups -Fatty acids are long chains of carbon and hydrogen ending in a carboxyl (-COOH) group |
How are triglycerides formed? What is an ester linkage? | Molecule of fat is formed when one molecule of glycerol combines with fatty acid molecules -Bond is called an ester linkage |
Differentiate between saturated and unsaturated fats. (Triglyceride Types) | A) Saturated fatty acids: -All carbons are linked via single covalent bonds -Solid at room temperature B) Unsaturated fatty acids: -One or more carbons are linked via double bonds -Liquid at room temperature |
What are complex lipids? | Phospholipids are a type of complex lipid -Complex lipids also contain elements such as phosphorous, nitrogen, and sulfur |
Describe phospholipids. | “Head” is a polar region and is attracted to water -“Tails” are nonpolar and are repelled by water •In place of a third fatty acid, phospholipids have a phosphate group bonded to glycerol |
What is the relationship between phospholipids and the cell membrane? | Phospholipids are important in cell membrane structure •Make a phospholipid bilayer •Separates contents of cell from water based environment it lives in |
Describe steroids. What is their relationship to phospholipids? | Composed of four interconnected carbon rings •Called sterols when an –OH group is attached to one of the rings •Part of plasma membranes of fungi and mycoplasma bacteria •Sterols separate the fatty acid chains in phospholipids |
What is a sterol? | any of a group of naturally occurring unsaturated steroid alcohols, typically waxy solids. |
Describe proteins. | Proteins are polymers of amino acid monomers held together by peptide bonds•Contain C, H, O, N, and sometimes S and P•Very large portion of a cell’s mass•Proteins are essential for cell structure and function•Have most varied functions of any molecules |
What are the functions of proteins? | -Enzymes -Transporter proteins -Bacteriocins: produced by bacteria to kill other bacteria -Toxins: produced by disease-causing microorganisms -Roles in movement of cells -Components of cell walls, membranes, and cytoplasm -Antibodies |
Describe the protein functions: Enzymes, Transporter proteins, and Bacteriocins. | Enzymes: proteins that speed up chemical reactions -Transporter proteins: proteins that transport chemicals into and out of cells -Bacteriocins: produced by bacteria to kill other bacteria |
Describe the protein functions: Toxins and Antibodies. | Toxins: produced by disease-causing microorganisms -Roles in movement of cells -Components of cell walls, membranes, and cytoplasm Antibodies: Roles in immune system of vertebrates |
What are proteins made of? | All proteins are made from 20 types of amino acids •Contain both an amino group and acid group •Differ by which of 20 different “R groups” is present |
How are proteins formed? What is a peptide bond? | Amino acids are joined together by covalent bonds called peptide bonds. |
Define Denaturation. What causes it? | Denaturation: proteins unfold and lose their 3-D shape. Causes protein to no longer be functional •Can be caused by changes in pH, temperature, or salt concentrations •reversible if normal conditions restored, Irreversible if changes are extreme |
Describe nucleic acids. What are the 2 classes? | •Nucleic acids: composed of C, H, O, N, and P •Genetic information of the cell 2 major classes: 1) Deoxyribonucleic acid (DNA) 2) Ribonucleic acid (RNA) |
Compare and contrast deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). | 1)Deoxyribonucleic acid(DNA):the blueprints for making proteins -Form 2 strands (double helix) 2)Ribonucleic acid(RNA):carry out DNA orders for protein synthesis -Single stranded -3 messengers= RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA) |
What are nucleic acids composed of? | Nucleic acids: composed of C, H, O, N, and P |
Describe the general structure of a nucleotide. | Nucleic acid polymers are made up of monomers called nucleotides Nucleotides are composed of: •nitrogen base •pentose sugar •phosphate group |
Define purine and pyrimidine. Which nitrogenous bases fit in each group? | Purine: double ring structure nitrogenous base -DNA and RNA = guanine (G) or adenine (A) Pyrimidines: single ring structure nitrogenous base -DNA = cytosine (C) or thymine (T) -RNA = cytosine (C) or uracil (U) |
How do the nucleotides of DNA and RNA differ? | -DNA = cytosine (C) or thymine (T) -RNA = cytosine (C) or uracil (U) |
How are nucleotides formed? What is a phosphodiester bond? | -The sugar of one nucleotide is joined to the phosphate of another via a phosphodiester bond -Forms the sugar-phosphate backbone of nucleic acids |
What is the sugar-phosphate backbone? | It is an important stuctural component of DNA. It consists of 5-carbon deoxyribose sugars and phosphate groups. The sugars are linked by a phosphodiester bond, between carbon 4 of their chain, and a CH2 group that is attached to a phosphate ion. |
How is a double strand of DNA formed? | Double stranded DNA is made due to hydrogen bonds that form between the nitrogenous bases of 2 strands of nucleic acids |
What are the complementary base pairing rules? | Base pair formation follows the complementary base-pairing rules: -A always pairs with T (U for RNA) -G always pairs with C |
Describe the structure of adenosine triphosphate (ATP) | Energy is captured in ATP (adenosinetriphosphate)•Adenine, ribose, and 3 phosphate groups. |
What is ATP used for? | ATP releases a large amount of usable energy when the third phosphate group is removed via hyrolysis (hydrolyzed). |