...HSC Biology – Blueprint of Life 4. The structure of DNA can be changed and such changes may be reflected in the phenotype of the affected organism. The phenotype of an organism is its total appearance determined during development by an interaction between its genetic make-up (genotype) and the environment. A genome is all of the genetic material (DNA) within a cell and is specific to each organism. Genomes influence nearly all the traits or phenotypes. The phenotypic appearance is therefore directly affected by gene expression. The extent of phenotypic differences depends on how different the DNA sequences are in individuals, but may also be influenced by the environment. • Outline evidence that led to Beadle and Tatum’s ‘one gene-one protein’ hypothesis and explain why this was altered to the ‘one gene – one polypeptide’ hypothesis Beadle and Tatum carried out experiments with red bread mould. The normal variety of mould can manufacture certain substances that it needs for living, including vitamin B1, B2, B4 and B12. The normal moult possesses specific enzymes that catalyse the different reactions that produce these vitamins. Beadle and Tatum produced several varieties of the bread mould, each of which had a change in one of its genes. They tested these varieties and found that some had lost their ability to make vitamin B2 while others could no longer make vitamin B4 and so on. The results obtained by Beadle and Tatum showed that a change in various...
Words: 5135 - Pages: 21
...Deoxyribonucleic acid makes up our genetics. It’s located in the nucleus of all cells. DNA is made up of deoxyribose sugar, a phosphate, and nitrogen base. There are four bases adenine, thymine, guanine, and cystone when paired up together (AT, CG) they start to make up a the shape of a twisted ladder (double helix) with sides made of alternating sugars and phosphates. The rungs (base pairs) or steps of the ladder are pairs of nitrogen bases. DNA has the information or instructions for building all of the cell's proteins. The proteins handle everything else. Alfred Hershey and Martha Chase discovered, through a series of experiments, in 1952 that DNA was made of genetic material. Before their discovery, most scientists had thought that proteins were the element that carried all genetic material. The confirmation that it was DNA that carried genetic material paved the way for a lot of advances in genealogy ,forensic science and the study of genetics to determine inherited diseases. Erwin Chargaff discovered what we know ar “Chargaff’s rules.” The first rule was that the number of guanine bases equals the number of cytosine bases, and that the number of adenine bases equals the number of thymine bases. The second rule was that the DNA varied from species to species. Rosalind Franklin helped in understanding the structure of the DNA by discovering the A and B forms of the DNA. She had applied the technique of x-ray diffusion in conducting her research. Franklin had figured...
Words: 486 - Pages: 2
...Contributions to the Discovery of DNA |Contributor(s) |Contribution | | |Demonstrated and quantified inheritance of traits between generations. 1857, Austria | |Gregor Mendel | | | |Discovered transformation. 1928, bacteriologist trying to develop a vaccine against Streptococcus pneumoniae. Two | |Frederick Griffith |strains, smooth edge (with polysaccharide capsule) and rough (without). S bacteria killed mice, R did not. Dead S | | |bacteria did not. Heat killed S. with the capsule did not. R bacteria mixed with heat-killed S bacteria killed mice. | |Vaccine |Material produced from weakened or killed microorganisms to stimulate an immune response and thereby protect the body | | |against infection. | |Transformation |A change in phenotype when bacterial; cells take up foreign genetic material. | | ...
Words: 890 - Pages: 4
...Technology Exam 2 Study Guide 1) Uses a promoter- transcription 2) An anticodon is involved in this process - translation 3) Codons are involved - translation 4) Uses DNA Polymerase- replication 5) Polymerase chain reaction is a “synthetic” version of this 6) RNA polymerase is used - transcription 7) Ribosomes are used- translation 8) tRNA is used - translation 9) mRNA is produced - transcription 10) mRNA is read - translation 11) Important when a cell divides- replication 12) Uses a start codon - translation 13) A stop codon is involved - translation 14) Ends with a termination sequence - translation 15) Begins at a promoter region - transcription 16)What are the two main types of cells? * Eukaryotes: animals, plants, yeast, algae, most multicellular organisms; yes nucleus * Prokaryotes: bacteria, archaebacteria, simpler organisms; no nucleus; no membrane enclosed organelles 17) Approximate size scale of bacterial cell (1 micron) vs. animal cell (10-100 microns) vs. molecules vs. virus 18) How does the cell fit 6 feet of DNA into each cell of our body? 19) How many chromosomes do humans have? What’s the difference between male and female chromosomes? 23; XX (female) versus XY (male) 20) Plasmids are the most important entity for biotechnology. They allow the insertion of foreign DNA 21) What was the first protein biotechnology to be produced in E. coli? 22) DNA: fingerprint...
Words: 3108 - Pages: 13
...here are basically three categories of chemicals normally functioning in the body—elements, inorganic compounds, and organic compounds: {draw:frame} Elements are components of all chemical compounds. Of the 92 naturally occurring elements, only 20 are normally found in the body. Seven of these, carbon, oxygen, hydrogen, calcium, nitrogen, phosphorous, and sulfur make up approximately 99% of the human body weight. In most cases, the elements are components of inorganic or organic compounds. In a few cases, however, elements themselves may enter into chemical reactions in the body, e.g., oxygen during cell respiration, sodium in neurotransmission, and arsenic and lead in impaired mitochondrial metabolism. Inorganic compounds are important in the body and responsible for many simple functions. The major inorganic compounds are water (H2O), bimolecular oxygen (O2), carbon dioxide (CO2), and some acids, bases, and salts. The body is composed of 60-75% water. Oxygen is required by all cells for cellular metabolism and circulating blood must be well oxygenated for maintenance of life. Carbon dioxide is a waste product of cells and must be eliminated or a serious change in pH can occur, known as acidosis. A balance in acids, bases, and salts must be maintained to assure homeostasis of blood pH and electrolyte balance. Organic compounds are involved in nearly all biochemical activities involved in normal cellular metabolism and function. The mechanisms by which xenobiotics...
Words: 1156 - Pages: 5
...Biology: Midterm 1 (Friday, October 2, 2015) Outcomes for Exam In multiple choice format questions, identify the following: 1. Characteristics of viruses and why they are not generally considered to be “alive”. * virus= infectious biological particles; 1+ nucleic acid molecules surrounded by protein capsid or envelope * nucleic acid: DNA or RNA, composed of single/double strand (genes encode coat proteins, proteins of regulation of transcription) * capsid: protein coat of virus, viral genome packaging * envelope: lipid bilayer that contains proteins * enveloped viruses: genomes contain genes for synthesis of envelope proteins * viral genomes= virus-specific enzymes (nucleic acid replication) * non-living organism/not “alive” - lack that properties of life (no independent reproduction, no metabolic system= no energy, dependent on host cells 2. Why viral infections are usually difficult to treat with drugs, and exceptions to this general principle. * viruses= hidden in host cells, use host cell machinery to replicate (no obvious viral product to be targeted by drugs/antibiotics - not like bacteria) * symptoms can only be relieved not treated - natural immune function treats — some viruses deadly symptoms= prevention w/ vaccinations (e.g. measles, polio) * Viruses using own polymerases (e.g. RNA viruses - influenza)= more obvious targets - antiviral drugs to treat 3. Whether viruses...
Words: 4973 - Pages: 20
...exoskeletons of insects and crustaceans is known as chitin. 2. Non-polarity and insolubility characterize biological compounds known as lipids. 3. Alpha helix and beta pleated sheets are examples of the secondary level of protein structure. 4. Components of nucleic acids include a five-carbon sugar, a phosphate group, an organic nitrogen containing base, and phosphodiester bonds. 5. Fructose and galactose all have the same six carbon atoms, twelve hydrogen atoms, and six oxygen atoms, just as glucose, but they are named differently because they are alternate forms of the monosaccharide, glucose . 6. Nucleic acids are created with phosphodiester bonds. 7. Nitrogen and carbon are common to all organic molecules. 8. Fuels such as gasoline are nonpolar and high in energy because they are largely composed of hydrocarbons. 9. Lipids serve as important energy stores and is a major component of plasma membranes. 10. The functional group -COOH has acidic properties and would release hydrogen ions in an aqueous (water) solution. 11. The peptidoglycan of the bacterial cell wall contains a carbohydrate matrix linked together by short chains of amino acids. 12. Nuclear pores apparently permit the passage of only proteins inward and outward, but RNA only outward. 13. Mitochondria and chloroplasts are the other organelles besides the nucleus that contain DNA. 14. The Golgi apparatus and ER are organelles that participate in the synthesis and modification of enzymes targeted to the plasma membrane. 15...
Words: 3437 - Pages: 14
...Biology Units 3 &4 Notes -Chapter 1- The Chemical Nature of Cells | |Protein |Carbohydrates |Fats |Nucleic acid | |Monomer |Amino acids |Monosaccharaide |Fatty acids, glycerol |Nucleotide | |Example |2o Amino acids |Glucose, Fructose, Ribose |Triglycerides |Adenine, Cytosine, Guanine | | | | |Steroids, Phospholipids |&Thymine/ Uracil | |Diagram | | | | | | | | | | | | | | | | | | | | | | | |Bonding (how units combine – |1st structure-strong covalent |Strong covalent glycoside |Rarely ever forms polymer |covalent bonds b/w sugar | |polymers ...
Words: 8693 - Pages: 35
...evidence found on fossils. Teeth can persist long after other skeletal structures have succumbed to organic decay or destruction by some other agencies, such as fire [3] [4]. Rugoscopy (study of palatal rugae patterns), cheiloscopy (study of lip prints), tooth prints, radiographs, photographic study and molecular methods like Polymerase chain reaction (PCR) are various methods used in the study of forensic odontology....
Words: 1794 - Pages: 8
...enzymes Restriction enzymes are DNA-cutting enzymes found in bacteria (and harvested from them for use). Because they cut within the molecule, they are often called restriction endonucleases. In bacteria the restriction enzymes naturally provide immunity to the bacteria against bacteriphage by cutting viral DNA is that introduced into the cell (Fig. 2 Page 280). After being cut, the viral DNA becomes inactive and thus the phage cannot attack the bacterial cell. A restriction enzyme recognizes and cuts DNA only at a particular sequence of nucleotides known as recognition sites. Most recognition sites are 4 to 8 base pairs long resulting in relatively low frequency of cuts compared to 2 base pair recognition sites. Example finding a 6 base pair recognition site for EcoRI is 46 i.e. once in every 4096 nucleotides. Whereas the probability of finding 2 specific bases next to each other is 42, once in every 16 nucleotides. More frequent cuts due to shorter recognition site results in a better chance to isolate a gene of interest. Recognition sites are characterized by a complementary palindromic sequence For example, the bacterium Hemophilus aegypticus produces an enzyme named HaeIII that cuts DNA wherever it encounters the sequence 5'GGCC3' 3'CCGG5' The cut is made between the adjacent G and C. This particular sequence occurs at 11 places in the circular DNA molecule of the virus phiX174. Thus treatment of this DNA with the enzyme produces 11 fragments...
Words: 1029 - Pages: 5
...for the Future Genetic Testing and Privacy CHAPTER OVERVIEW Chapter 1 provides a glimpse of the basic concepts of genetics and genomics, and offers examples of DNA information impacting daily life. In this new era of genomics, individuals have access to their own genetic information, and health care providers are learning how to incorporate DNA data into diagnostic and therapeutic medicine. Bioethics deals with issues of privacy, discrimination, and justice that arise from use and misuse of genetic information. DNA, genes, chromosomes, and genomes are the levels of genetic information, and they impact biology at the cell, tissue, organ, individual, family, and population levels. Genes encode proteins, and the exome is the small part of the genome that does so. Most traits arise from interactions of genes and environmental factors. Genetic information is in health care to identify individuals, in investigating the environment, and in understanding evolution. CHAPTER OUTLINE 1.1 Introducing Genes and Genomes 1. Genetics is a branch of biology concerned with inherited traits and their variation, and how these traits are passed from one generation to the next (heredity). 2. With continuing analysis of human genome sequences, human genetics has grown from a largely academic science to touch many areas of medicine, with practical and societal implications. 3. Genes are the unit of inheritance and are composed of DNA. 4. An organism’s genome...
Words: 1773 - Pages: 8
...MULTIPLECHOICE SECTION INSTRUCTIONS: Read all instructions carefully. Please answer all questions. Each question is worth 0.5 points. The Multiple Choice section is worth 40 points. **Do not enter your answers here.** Type in the letter you select as the best answer on the Answer Sheet provided by your instructor. 1. Which of these would be a valid hypothesis? A) Human history is determined by a series of supernatural events. B) Humans should help in the conservation of other animal species. C) Humans are controlled by forces beyond our understanding. D) Humans and bacteria share a common genetic code. 2. In the scientific method, a hypothesis . E) is a statement of fact F) can only be tested once G) is usually proven to be correct H) is a proposed explanation based on observations I) none of the above 3. What is the correct sequence of steps in the scientific method? I. State the problem II. Analyze and interpret the data III. Share the results with other scientists IV. Develop a hypothesis V. Design and perform an experiment to test the hypothesis A) I → II → III → IV → V B) III → I → V → II → IV C) V →IV → III → II → I D) I → IV → V → II → III E) V → II → I → III → IV 4. To test a hypothesis about a given variable, experimental and control groups are tested in parallel. Which of the following best explains the dual experiments...
Words: 6163 - Pages: 25
...DNA is known to be the most common unit of genetic material in life on Earth; however, Genetic information is stored within the chemical structure of the DNA ,the two backbones, which form double helix , a chain of four chemicals which called bases , and they are running along the backbones , as well as base pairs which are Bridges between bases that located on opposite backbones , The four bases are indicated by the letters A, T, C and G, and their order form a genetic "code" , A,T,C,G can be called triads or codons ,they carry a specific code or message that cells can understand ,and each code or message tells the cell to make for examples black hair, or make green eyes or help a person to grow tall or shorter, however ,DNA molecules are able to make copies of themselves during cell division or when the cell reproduces, usually the DNA molecules contains two identical molecules that were produced from one single parent molecule. When fertilizing an egg cell with a sperm cell, the sperm gives DNA to the fertilized egg and the egg has its DNA already , as we know...
Words: 1039 - Pages: 5
...Study Guide: Biochemistry A. Hydrophilic vs Hydrophobic. Since biological chemistry occurs largely in an aqueous environment, the interaction of a biological molecule with water is very important. That interaction is influenced by two primary causes: size and polarity (charge). The smaller a molecule is, the more likely it is to be willing to associate with water (dissolve). Also, the more polar and/or charged a molecule is, the more likely it is to be willing to associate with water. Since biological molecules are often very large, it is common for the different parts of the molecule to interact differently in water. For instance, a protein, which is composed of many different amino acids which have a large variety of characters, may be hydrophobic in part of its sequence and hydrophilic in other parts. Hydrophilic (hydro=water; philios=love): Hydrophilic molecules or parts of molecules will dissolve in (interact with) water. Hydrophobic (hydro=water; phobio=fear): Hydrophobic molecules or parts of molecules will refuse to interact with water. If sufficiently hydrophobic, a molecule or part of a molecule will actively repel or exclude water. Hydrophilic/phobic characters are not an all-or-none phenomenon. Molecules fall along a scale, somewhere between extremely hydrophobic and extremely hydrophilic. Changing the parts of a molecule will often shift it more toward the hydrophobic or the hydrophilic end of the scale (depending upon the change)...
Words: 2812 - Pages: 12
...asddsaProteins (/ˈproʊˌtiːnz/ or /ˈproʊti.ɨnz/) are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within living organisms, including catalyzing metabolic reactions, DNA replication, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20-30 residues, are rarely considered to be proteins and are commonly called peptides, or sometimes oligopeptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residues in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the genetic code specifies 20 standard amino acids; however, in certain organisms the genetic code can include selenocysteine and—in certain archaea—pyrrolysine. Shortly after or even during synthesis, the residues in a protein are often chemically modified by posttranslational modification, which alters the physical and chemical properties, folding, stability, activity...
Words: 2229 - Pages: 9
