Test Answers on EXAM 2 – Microbiology – Flashcards
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| How many covalent bonds are formed by one carbon, and why? |
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| 4, b/c it has 4 valence electrons |
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| When a double covalent bond is formed, how many electrons are being shared? |
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| 4 (2 in each bond) |
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| Given a molecule that was drawn incorrectly, indicate which carbon does not have a sufficient number of bonds. |
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| It is organic, because it has both hydrogen and carbon |
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| Given a molecular formula (such as CH4) identify the molecule as inorganic or organic. |
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| It is organic, because it has both hydrogen and carbon |
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| Given an organic molecule (molecular or structural formula) indicate whether the molecule is hydrophobic or hydrophilic and why. |
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| Hydrophilic – water loving(philic), soluble, polar Hydrophobic – water fear (phobic), nonpolar, |
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| Given two molecules, identify whether they are isomers of each other and explain why. |
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| Isomers - same molecular formula, different structure. |
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| Explain the importance of functional groups. Be able to identify and name all functional groups. |
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| Functional group is important b/c it will make it easier to identify different organic molecules |
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| Macromolecule |
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| very large molecules |
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| Dimer |
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| two monomers or 2 sun-units combined by dehydration synthesis |
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| Polymer |
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| 3 or more monomers combined my dehydration synthesis |
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| Hydrolysis |
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| break dimer into 2 monomers |
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| Monomer |
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| single sub-units of larger molecules |
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| Dehydration synthesis |
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| joins 2 monomers |
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| What are the four major categories of organic molecules, and what atoms are in each type? |
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| Carbohydrates C H O Lipids C H O Protein C H O N S Nucleic acid C H O N P |
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| What ratio of carbon: hydrogen: oxygen is typical of carbohydrates? Be able to recognize a carbohydrate from its molecular or structural formula. |
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| 1:2:1 |
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| In comparison to carbohydrates, what atom is present in much lower quantities in lipids? |
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| O |
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| Realize that in carbohydrates, monomers are called monosaccharides, dimers are called disaccharides, and polymers are called polysaccharides. |
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| List the five major monosaccharides, and for each indicate its molecular formula, where it is primarily found, and its major function. Hint: the name “Dr. Frugal Glue (a doctor who liked to buy cheap glue” may help you remember Deoxyribose, ribose, fructose, galactose and glucose. |
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| Glucose C6H12O6 blood and cells energy Fructo C6H12O6 fruit energy Galactose C6H12O6 milk energy Ribose C5H10O5 RNA heredity Deoxyribose C5H10O5 DNA heredity |
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| List the 3 major disaccharides. For each indicate the 2 monosaccharides of which it is composed, and where it is found. Recognize that to digest monosaccharides into monosaccharides a hydrolysis reaction must occur, and a particular enzyme is required. To help you remember the disaccharides remember that Sue likes to go to downtown Columbia to visit the lake and the mall (sucrose, lactose, maltose). |
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| 1) Sucrose glucose– fructose plant table sugar 2) Lactose galactose – glucose milk 3) Maltose glucose – glucose degradation of starch |
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| Given a molecule that was drawn incorrectly, indicate which carbon does not have a sufficient number of bonds. |
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| Carbon needs to have four bonds |
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| Given a molecular formula (such as CH4) identify the molecule as inorganic or organic. |
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| It is organic, because it has both hydrogen and carbon |
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| Given an organic molecule (molecular or structural formula) indicate whether the molecule is hydrophobic or hydrophilic and why. |
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| Hydrophilic – water loving(philic), soluble, polar (o,n) (ionic bond) Hydrophobic – water fear (phobic), nonpolar, |
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| Given two molecules, identify whether they are isomers of each other and explain why. |
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| Isomers - same molecular formula, different structure. |
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| Explain the importance of functional groups. Be able to identify and name all functional groups. |
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| Functional group is important b/c it will make it easier to identify different organic molecules |
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| Macromolecule |
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| very large molecules (polymer) |
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| Monomer |
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| single sub-units of larger molecules |
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| Dimer |
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| two monomers or 2 sun-units combined by dehydration synthesis |
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| Polymer |
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| 3 or more monomers combined my dehydration synthesis |
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| Describe the chemical reactions of dehydration synthesis and hydrolysis in terms of what occurs, and what is accomplished. (Which can bond together monomers? Which splits a dimer or polymer into monomers? Which utilizes a water molecule, which is split? Which forms a water molecule after an H and OH are removed from two monomers?) |
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| Dehydration synthesis- joins 2 monomers Hydrolysis- break dimer into 2 monomers |
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| What are the four major categories of organic molecules, and what atoms are in each type? |
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| Carbohydrates C H O Lipids C H O Protein C H O N S Nucleic acid C H O N P |
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| 13. Realize that in carbohydrates, monomers are called monosaccharides, dimers are called disaccharides, and polymers are called polysaccharides. |
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| monosaccharides disaccharides polysaccharides |
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| 14. List the five major monosaccharides, and for each indicate its molecular formula, where it is primarily found, and its major function. Hint: the name “Dr. Frugal Glue (a doctor who liked to buy cheap glue” may help you remember Deoxyribose, ribose, fructose, galactose and glucose |
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| Glucose C6H12O6 blood and cells energy Fructose C6H12O6 fruit energy Galactose C6H12O6 milk energy Ribose C5H10O5 RNA heredity Deoxyribose C5H10O5 DNA heredity |
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| 15. List the 3 major disaccharides. For each indicate the 2 monosaccharides of which it is composed, and where it is found. Recognize that to digest monosaccharides into monosaccharides a hydrolysis reaction must occur, and a particular enzyme is required. To help you remember the disaccharides remember that Sue likes to go to downtown Columbia to visit the lake and the mall (sucrose, lactose, maltose) |
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| 1) Sucrose glucose – fructose Table sugar/plants 2) Lactose galactose – glucose milk sugar 3) Maltose glucose – glucose degradation of starch |
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| 16. List the 4 major polysaccharides, and recognize that they are all composed of long chains (polymers) of glucose. For each indicate where it is found, its function, and whether it can be digested by animal enzymes. Also, explain how cows are able to obtain calories from cellulose even though they themselves do not produce the needed enzyme. To help you remember the polysaccharides, remember Glynda who liked to eat starch, but would also chew on celery (glycogen, starch, chitin, cellulose). |
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| Starch -plant/bread/potatoes! Glycogen -animals (liver, muscle cell) Chitin -indigestible by animal (beetles shell) fibers that gives structural support to exoskeleton Cellulose- not indigestible by animal fibers that gives structural support to plant cell wall |
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| Chitin |
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| indigestible by animal (beetles shell) fibers that gives structural support to exoskeleton |
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| Starch |
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| plant/bread/potatoes |
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| Glycogen |
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| animals (liver, muscle cell) |
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| Cellulose |
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| not indigestible by animal fibers that gives structural support to plant cell wall |
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| Describe the basic structure of DNA. Why is called a double helix? |
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| It called the double Helix because it is composed of two double strands wrapped around each other in a helical manner |
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| What is a nucleotide? |
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| It serves as a building block of nucleic acids |
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| What are the 4 different nucleotides? |
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| Adenine (A) Guanine (G) Cytosine (C) Thymine (T) |
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| Which nucleotides are the purines and pyrimidine? |
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| Purine A and G Pyrimidine C and T |
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| What are the basic components of a nucleotide? |
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| a. A sugar deoxyribose b. A phosphate group c. A nitrogen/nitrogenous base |
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| What enzyme is needed to unwind DNA? |
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| Enzyme helicase |
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| What is the result of DNA replication? |
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| 2 identical DNA molecules |
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| Describe the process of DNA replication. |
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| 1.Hydrogen bond breaks 2.Free nucleotides are found to produce new strands of DNA |
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| What physical property do all lipids have in common? Why? |
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| Hydrophobic, non-polar molecule |
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| What are the four major useful characteristics of fats and oils? |
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| 1)Compact energy storage 2)Aid in absorption and storage of fat-soluble vitamins (A, D, E, K) 3) Fat provide heat insulation 4) Fat protects and cushion organs |
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| What building blocks or monomers compose a fat or oil? |
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| Glycerol and fatty acids |
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| Be able to recognize each of the following from its structural formula: glycerol, fatty acid, saturated fatty acid, polyunsaturated fatty acid, monounsaturated acid. |
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| polyunsaturated fatty acid |
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| monounsaturated acid |
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| glycerol |
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| fatty acid |
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| saturated fatty acid |
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| What reaction is used to bond together glycerol to 3 fatty acids? What reaction is used to break apart a fat into glycerol and 3 fatty acids? |
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| Dehydration-bond 3 hydrolysis- breaks |
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| Compare plant oils and animal fats in terms of which tends to be more saturated, which tends to be more unsaturated, which tends to be liquid at room temperature, and which tends to be solid. |
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| Oil – unsaturated (liquid) Fat- saturated (solid) |
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| At a molecular level, why is it that saturated fats tend to be more solid than unsaturated fats? |
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| Saturated- no double bond in the hydrocarbon chain, fatty acids pack together and tend to be solid, high density, stick well, straight chains Unsaturated – double bond between carbon and hydrocarbon chain, fatty acids tend to slide past each other and cannot stick together. Low density, liquid, don’t stack well, and bend |
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| What process is used to convert liquid vegetable oils to solid fats? |
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| Hydrogenation process- use a catalytic process and hydrogen gas to hydrogenate the molecules |
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| What type of fatty acid is formed when the hydrogenation process occurs that may have an adverse affect on health? |
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| Trans fatty acids |
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| List three major categories of lipids other than fats and oils? |
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| Wax – protect ear form microorganisms, protect plants from losing water, bee (honeycomb) Phospholipids – cell membrane is composed largely of phospholipid molecules Steroids - Testosterone (male sex hormone), estrogen (female sex hormone), Aldosterone (a hormone that regulates water balance) |
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| For phospholipids, what part of a cell do they compose? |
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| Composed of cellular membranes, both plasma membrane and membranes in organelles |
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| For steroids, recognize that although they are varied in function (know examples), they have the same basic structure. What is the structure they have in common? |
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| it has four rings |
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| Know that proteins are composed of polypeptides. Polypeptides are polymers of what type of monomer? |
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| Amino acid |
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| What two functional groups are present in all amino acids? |
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| Amino and carboxyl |
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| What is the part of the amino acids that varies? |
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| R-group |
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| How many amino acids are in proteins in living organisms? Given a structural formula, recognize a molecule as an amino acid. |
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| 20 |
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| By what processes are amino acids joined together and taken apart? |
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| Dehydration synthesis |
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| What is the name of the covalent bond that is formed between 2 amino acids? |
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| Peptide Bonds |
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| What determines the sequence of amino acids in proteins? |
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| mRNA or DNA |
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| Describe the 4 levels of protein organization |
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| Primary – sequence of amino acid and chain length (unstable, not fully function, found in ribosomes, nucleus Secondary –coiling and pleated sheet (unstable and not function, find in ribosomes) Tertiary – 3d (has function) Quaternary- 2 or more proteins connected |
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| What does it mean to denature a protein? What factors can cause denaturation? Why does that explain how heat or changes in pH can kill organisms |
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| Dentures- when a protein encounters an unpleasant environment, the protein change its shape by breaking the bond Protein has a very specific temp, pH, and salt concentration |
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| What are the major examples of proteins and their functions? |
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| Enzymes – responsible for all chemical reaction in cells (workers) Collagen – it’s in protein in connective tissue (bone, Skin) Hormones – they are chemical messengers for cells (insulin) Hemoglobin – the protein in blood that carries oxygen |
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| What are the similarities and differences of DNA and RNA? |
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| RNA - ribose, 1 strands, A,G,C,U DNA - deoxyribose, 2 strands, A,G,C,T |
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| Describe and explain what is meant by transcription and translation. |
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| Transcription is a copy inside and translation is outside the |
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| Indicate where and how translation and transcription occurs in eukaryotic cells. |
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| Translation- Cytosol Transcription- nucleous |
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| mRNA |
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| carries message from DNA |
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| tRNA |
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| rtansfers amino acids |
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| anticodon |
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| opposite of codon (on tRNA) |
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| codon |
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| every three (ex: AUG(always start from this) ccu etc) |
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| Be able to distinguish between each of the mutation outcomes. |
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| Silent, nonsense, missense |
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| Predict the consequences of a mutation in a DNA molecule to the amino acid sequence of the polypeptide form. |
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| Explain what is meant by the concept “one gene-one polypeptide”. |
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