BIOLOGY FINAL
TERM
Active site
DEFINITION
The specific portion of an enzyme that attaches to the substrate by means of weak chemical bonds The emergence of numerous species from a common ancestor introduced into an environment that presents a diversity of new opportunities and problems.
FROM LECTURE NOTES
Region on the enzyme which binds with the substrate (usually a pocket or groove on surface of the enzyme) a. Single Common ancestor introduced into a new and diverse environment. 1) These new species exploit different ecological niches a) examples: (1) Galapogos finches (a) each species ahs a different beak sized and shape --adapted to these different diets. 2. Honeycreeper (bird) introduced into the Hawaian island from one species. There are now 14 different species. b. often seen when new habitat is colonized refers to the number of protons in the atomic nucleus. This Identifies the element. e.g.: Carbon has 6 protons C6 Nitrogen has 7 protons C7 Oxygen has 8 protons O8
Adaptive radiation
Atomic number
The number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol See Lab Power Point
Be able to read a DNA fingerprint and Gel glycorisis Cells Characteristics of water
Life’s fundamental unit of structure and function every organisms basic unit of structure and function.
Cell – Smallest unit of living matter.
Water Molecules are cohesive (stick together) (1) Enables capillary action (2) Creates tension at the surface, water molecules interact with each other (many hydrogen bonds), not with air. That is why light things float (not heavy enough to disrupt bonds). c) water has a high specific heat (1) definition of specific heat—the amount of heat required to change 1 gram of a substance one degree centigrade (2) It takes a tremendous amount of energy to change the temperature of water
Citric acid cycle pyruvic acid is converted to what? The division of the cytoplasm to form two Cytokenisis in plants separate daughter cells immediately after and animals. Know mitosis. about cell plate in plants, cleavage furrows in animal cells Describe the appearance of a cell in metaphase
Pyruvic acid is converted to acetyl coenzyme A (acetyl CoA)
cytokinesis 1) separation of the cytoplasm 2) produces two daughter cells 3) in plants – cell plate forms between plant cells 4) in animals – cleavage furrow forms between the cell.
The third stage of mitosis, in which the spindle is Metaphase a. Nuclear envelope is completely gone. complete and the chromosomes, attached to b. sister chromatids line up at the metaphase plate (this is an imaginary plate) microtubules at their kinetochores, are all 1) after a ‘tug of war’ with the kinetochore microtubles. aligned at the metaphase plate. 2) Centromeres on the metaphase plate c. non-kinetochre microtubles (polar microtubles) growing form one pol interact with those
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BIOLOGY FINAL
TERM
Differentiate between Organic and inorganic
DEFINITION
FROM LECTURE NOTES
Organic compounds a. Contain carbon b. Hydrocarbons contain only hydrogen and carbon c. Over 2 million known Inorganic compounds a. Do not contain carbon
Differentiate between sugars in rna and dna
RNA = A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually singlestranded; functions in protein synthesis and as the genome of some viruses. Deoxyribonucleic acid (DNA) A doublestranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell’s proteins
RNA sugar is ribose (C5H10O5); DNA sugar is deoxyribose (C5H10O4)
Diploid
A cell containing two sets of chromosomes (2n), Diploid (usually written as 2n) one set inherited from each parent. a) it has two complete sets of chromosomes (1) one is inherited from the father (2) one is inherited from the mother. b) They are found in the somatic (body cells exclusive of sex cells) Dominant: a genetic feature that hides the recessive trait in the phenotype of an individual; denoted with a capital letter Summary: Energy output of cellular respiration a. glycolysis : 2 APT produced b. Citrix acid (Crebs Cycle: 2 ATP c. Electron transport chain: 34 ATP d. Total energy output of all stages--_38____ATP A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles, present in protists, plants, fungi, and animals; also called eukaryote. Evolution All the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today Speciation The origin of new species in evolution.
Dominant
Energy output of cellular respiration, glycolysis, electron transport chain, citric acid cycle Eukaryotic cell Evolution and speciation
Fermentation aerobic or fermentation A catabolic process that makes a limited amount anaerobic?
of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.
Fermentation is an anaerobic process (requires no oxygen)
Food crops
Most important food crops are polyploids examples: potatoes, peanuts, apples, and wheat
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BIOLOGY FINAL
TERM DEFINITION FROM LECTURE NOTES
4 major elements found in living things are oxygen, carbon, hydrogen and nitrogen
Four major elements found in living things FUNCTION of restriction restriction enzyme A degradative enzyme that recognizes and cuts enzymes
Restriction enzymes are the cutting tools in the gene cloning process; hundreds of restriction enzymes have been identified up DNA (including that of certain phages) that is • a very specific cutting tool that recognizes particular sequences of nucleotides on DNA strands • these sequences of nucleotides are called palindromes (nucleotides that read the same forward and foreign to a bacterium in reverse) • cuts the DNA into fragments in which the cut ends are not always even • uneven cut strands are called “sticky” and have exposed bases
Given substances be able to tell if acidic or basic like tomato juice
from 1-6.9 on the PH scale is acidic (H+ concentration higher than 0H- concentration) a) examples: (1) Hydrochloric Acid (2) Tomato Juice (3) Urine 7 on the pH scale is neutral (H+ concentration and OH- concentration is equal) a) example (1) pure water 3) 7.1 to 14, is basic (OH- concentration higher than H+ concentration) a) examples (1) Ammonia (2) Bleach (3) Sea Water d. BuffersSubstances that minimize changes in the acidity of a substance. The concentration of OH- and H+ in solution. Habitat isolation – two species live in the same area but are found in different habitats, e.g. one species of garter snake lives primarily in water, while another lives mostly on land; also parasites living on different hosts haploid cell A cell containing only one set of chromosomes (n). Haploid (usually written as n) a) has one complete set of chromosomes b) gametes (1) egg (2) sperm
Habitat isolation
Haploid
Heterozygous Hybrid sterility
heterozygous Having two different alleles for a given gene. hybrid sterility – the zygote survives but is sterile, as in the mule produced by a female horse and male donkey or the hinny produced by a female donkey and male horse Induced fit: the process which strains substrate bonds to place in position for a reaction to take place DNA base pairings: thymine-adenine and guanine-cytosine RNA base pairings: uracil-adenine and guanine-cytosine
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Induced fit (enzyme related)
Know base paring rules in DNA and RNA
BIOLOGY FINAL
TERM
Know basic carbohydrate formula Know characteristics of carbon Know domain in taxonomy and ex of organisms in each. Know homozygous Know importance of each trace elements from lecture.
homozygous Having two identical alleles for a given gene Selected trace elements – elements our body’s needs is minute amounts in order to survive. 1) Iron – important in energy processing in the body. Also helps in the transport of oxygen in the blood. 2) Essential ingredient of thyroid hormone. No iodine causes enlargement of the thyroid gland called Goiter. Using iodized salt prevents goiters. Florine – a. reduces tooth decay
DEFINITION
Carbohydrates
FROM LECTURE NOTES
a. Basic Formula CH2O – MEMORIZE!! Different forms include the hardest naturally occurring substance (diamond) and also one of the softest substances (graphite) known. Moreover, it has a great affinity for bonding with other small atoms, including other carbon atoms, and is capable of forming multiple stable covalent bonds with such atoms. Domains: Archaea – prokaryotes Bacteria – prokaryotes Eukarya – e.g. humans, trees, mushrooms, algae
Know method of recombination bacterials conjugation transformation, transduction
Methods of Recombination conjugation – requires contact between a donor and recipient cell; plasmids (with 20-100 genes) are usually transferred transduction – bacteriophage transfers bacterial genes from a donor cell to a recipient cell transformation – a. bacteria dies & releases DNA to the environment b. other bacteria take up this DNA (the ability to do this is called competency) c. new DNA is incorporated into the bacteria’s own DNA
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BIOLOGY FINAL
TERM DEFINITION FROM LECTURE NOTES
scientific method (cont'd) (1) Do 2 different tests done in parallel (a) Experimental test (b) One is the control test (2) Differ only in one fact e) Repeat the experiment to make sure the results are reliable and valid (1) use statistics--selected examples (a) Average (b) Standard Deviation (2) Sample error can be introduced if the sample size is too small f) compare results with hypothesis (1) results may contradict hypothesis. If so, hypothesis is incorrect. (2) Results may be consistent w/hypothesis. Hypothesis may be correct. Should be tested further to confirm results are reliable and not a fluke. b. Results therefore may prove or disprove hypothesis. 1)Support is a very important word (it is very difficult to "prove" anything with absolute certainty) 2) Hypothesis called theory such as gravity or evolution, are ones that have been supported many times by a wide range of evidence 7. Example of the scientific method a. Observation – I have a flashlight that does not work b. Questions 1) Is the bulb burned out? 2) Are the batteries dead? c. Hypothesis 1) The bulb is burned out d. Predict 1) Replacing the bulb will fix the problem Cytoskeleton components Microtubules 1) Structure: straight hollow tubes; composed mainly of tubulins (globular proteins); diameter – 15nm 2) Function a) Essential for cell division (Taxol, a drug used to treat cancer, prevents these microtubules from forming) b) Form flagellum (long, seen in sperm) (1) Undulating motion (2) 9+2 arrangement of microtubules – occur in doublets c) Form cilia (short, seen in bacteria) – have an oar-like movement d) Tracks for organelle movement & guide for movement of chromosomes Intermediate filaments 1) Smaller than the microtubules – they are 8-12nm 2) Made of fibrous protein 3) Used for reinforcing cell shape 4) Anchors the nucleus of the cell & some other organelles Microfilaments 1) Smaller than the intermediate & microtubules – they are 7nm 2) Solid rods composed of actin (globular protein) 3) Involved in cell movement (e.g. amoeboid and white blood cell – “cell crawling”) 4) Support the cell’s shape 5) Helps in cell division (e.g. cleavage furrow)
Know observation Know scientific method Memory Aid: Owls Quickly Hide Peanuts Today
1. Observations a. from previous studies b. Scientist personal own background 2. Questions a. arise from observations b. usually are focused c. lead to a hypothesis 3. Hypothesis a. Possible answer to the questions b. Usually many more possible answers to a particular questions 4. Predictions a. Use what is known as deductive reasoning b. bases on testable hypothesis 1) those hypothesis that can be tested / examined experimentally 2) hypothesis that involve Magic, etc. are not considered testable .5. Tests a. Experiments to test the hypothesis 1) experimental design a) Gather as much background information b) formulate a focused hypothosis with a y/n question c) Choose a quantitive variable to be studied
Know structure and function of each component of cytoskeleton like microfilaments
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BIOLOGY FINAL
TERM
Know the summary of miosis
DEFINITION
FROM LECTURE NOTES
Know subphases of cell cycle and what happens in each
Phases of the Cell Cycle (M) phase, includes mitosis and cytokinesis, is usually the shortest part of the cell cycle. A longer stage called interphase, accounts for about 90% of the cycle. It is during interphase that the cell grows and copies its chromosomes in preparation for cell division. Interphase can be divided into subphases: the G1 phase (“first gap”), the S phase (“synthesis”), and the G2 phase (“second gap”). During all three subphases, the cell grows by producing proteins and cytoplasmic organelles such as mitochondria and endoplasmic reticulum. However, chromosomes are duplicated only during the S phase (synthesis of DNA). Thus, a cell grows (G1), continues to grow as it copies its chromosomes (S), grows more as it completes preparations for cell division (G2), and divides (M). The daughter cells may then repeat the cycle. A typical human cell might undergo one division in 24 hours. Of this time, the M phase would occupy less than 1 hour, while the S phase might occupy about 10–12 hours, or about half the cycle. The rest of the time would be apportioned between the G1 and G2 phases. The G2 phase usually takes 4–6 hours; in our example, G1 would occupy about 5–6 hours. G1 is the most variable in length in different types of cells. Mitosis is conventionally broken down into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. Overlapping with latter stages of mitosis, cytokinesis completes mitotic phase M Summary of Division time (typical human cell) 1) one complete cycle: 24 hours 2) G1 – 5-6 hours 3) S –10-12 hours
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BIOLOGY FINAL
TERM
Know the DNA methods of PCR polymerase chain reaction and nucleic acid probes.
DEFINITION
FROM LECTURE NOTES
DNA Technology Methods Nucleic acid probes : short strands of DNA with complementary bases for the particular gene of interest are labeled with radioactive or fluorescent dye and can be used to find a specific gene in a mass of DNA. PCR (polymerase chain reaction): requires a DNA sample, primers, heat stable DNA polymerase (so it will not denature at high temperatures; was first isolated from prokaryotes living in hot springs), and a thermal cycling machine Process: • DNA sample mixed with DNA polymerase • DNA fragments separate at high temperatures • DNA polymerase copies the DNA to a complementary strand • DNA fragments separate again at the high temps • cycle repeated 30-100 times Uses: to determine if an individual is a carrier for a disease, look at genetic relationships between species, or to create a DNA fingerprint • Every individual has a unique sequence of bases in their DNA; this sequence will be shared with relatives • with this you can establish a relationship between people (e.g. paternity cases) or conclusively identify a criminal from DNA left at a crime scene (only 1/1 billion chance of being incorrect)
Know X chromosome inactivation. Lysogenic and lycic cycle of virus?
lysogenic cycle A phage replication cycle in which the viral genome becomes incorporated into the bacterial host chromosome as a prophage and does not kill the host. lytic cycle A type of viral (phage) replication cycle resulting in the release of new phages by lysis (and death) of the host cell.
X-chromosome inactivation - one X-chromosome in a female mammal is inactivated; inactivation occurs at random example: calico cat Viral life cycles: lytic cycle – 1) virus infects the host cell 2) DNA is replicated, transcribed & translated 3) new viruses are assembled 4) the host cell lyses, releasing new viruses lysogenic cycle – 1) viral DNA inserts itself into the host’s DNA 2) each time the host cell divides, it replicates the viral DNA 3) single infected bacterial cell gives rise to a large population of infected cells
Mechanical isolation
Mechanical isolation – the sex organs are incompatible, e.g. many flowers are adapted to a particular Mechanical isolation – the sex organs are incompatible, e.g. many flowers are adapted to a species of animal pollinators and others can’t reach the pollen; male copulatory organs in many insects are unique and complex particular species of animal pollinators and others can’t reach the pollen; male copulatory organs in many insects are unique and complex
Osmosis
osmosis The diffusion of water across a selectively permeable membrane
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BIOLOGY FINAL
TERM
Phagocytocis
DEFINITION
FROM LECTURE NOTES
phagocytocis (cell-eating) which is the uptake of solid material into the cell phagocytosis a. examples: A type of endocytosis involving large, particulate -amoeba takes up food in this manner substances, accomplished mainly by - white blood cells also takes up bacteria in this manner. macrophages, neutrophils, and dendritic cells.
Know Photosynthesis summary
1. Summary equation 6-CO2 + 12-H2O + solar energy, pigments, and enzymes yields C6 H12 06 + 6-H2O+6-O2 2. Photosynthesis is a series of endogonic reactions a. Solar energy runs reactions. b. Reactions: CO2 and H2O c. Products: High energy molecule – glucose plus new H2O and O2 3. Stages of photosynthesis a. Light reactions 1) Solar energy is converted to chemical energy(ATP and NADPH) 2) O2 is a by product 3) Reactions take place in the thylakoid membrane. 4) Because these reactions require the input of light energy and they occur in the presence of light, they are therefore called light reactions. b. Calvin Cycle (dark reactions) 1) Chemical energy from TP and NADPH is used to produce glucose 2) Reactions take place in the stroma 3) These reactions do not require light so also called the dark reactions.
Pinocytosis.
pinocytosis A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.
Pinocytosis (cell drinking) – the uptake of fluids.
Population
population A localized group of individuals that belong to the same biological species (that are capable of interbreeding and producing fertile offspring).
members of a single species i.e. squirrels and roaches
Prokaryotic cell
lack a membrane enclosed nucleus and membrane enclosed organelles prokaryotic cell A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea
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BIOLOGY FINAL
TERM
Proto oncogene
DEFINITION
proto-oncogene A normal cellular gene corresponding to an oncogene; a gene with a potential to cause cancer but that requires some alteration to become an oncogene.
FROM LECTURE NOTES
1) Oncogene a. A gene that causes a normal cell to become cancerous. b. RAS Oncogene is one that over stimulates cell division. 2) Proto Oncogenes a. Normal gene that transition into oncogenes if mutated. b. most found in somatic cells c. most produce growth factors d. when functioning normally 1) control cell division 2) “ cell cycle e. examples of _Proto-oncogenes and diseases they cause 1) Growth factor genes a) colon cancer b) Kidney cancer c) Stomach cancer
Receptor mediator endocytosis
receptor-mediated endocytosis The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.
Recessive be able to use this to solve genetic problems. Solve problems using the harty winberg equilibrium Species
Recessive: an allele that causes a phenotype that is only seen in homozygous genotypes and never in heterozygous genotypes; denoted with a lowercase letter
species A group whose members possess similar anatomical characteristics and have the ability to interbreed lysosome A membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of eukaryotic cells. if they breakdown within the cell because of their hydrolytic enzyme, it will kill the cell.
Structure and function of a lysosome
Sympatric isolation
sympatric speciation by polyploidy – two populations of plants become reproductively isolated even though they live in the same area; these plants have a polyploid cell (a cell with more than 2 sets of chromosomes) a. examples of polyploid food crops: potatoes, peanuts, apples, & wheat
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BIOLOGY FINAL
TERM
Telomeres
DEFINITION
FROM LECTURE NOTES
telomere Telomeres: the protective structures at the end of a chromosome that protect the genes from being The protective structure at each end of a eroded by successive rounds of replication; have a particular nucleotide sequence of TTAGGG that eukaryotic chromosome. Specifically, the can have repetitions of 100-1000 sequences per telomere tandemly repetitive DNA at the end of the chromosome’s DNA molecule. See also repetitive DNA transposon A transposable genetic element that moves within a genome by means of a DNA intermediate Speciation models Gradualist model of speciation – changes occur gradually over long periods of time and new species are produced by the steady accumulation of small changes Punctuated equilibrium model of speciation – stages of little or no change interspersed with rapid bursts of speciation (both types can be found in the evolutionary history of a single species of an organism) Light microscope
Transposons
Two models of speciation
Type of microscope used to observe living cells. Types of chemical bonds and characteristics of
Chemical Bonds 1) Attraction between atoms a. Valence electrons – electrons in outer most shell b. Valence shell – outermost shell c. Valence (bonding capacity) usually equals the number of unpaired electrons. d. Bonding mechanisms – atoms transferring or sharing of the valence electrons. Types of Bonds a. IONIC bonds 1) Attractions between ions. (are those atoms which have gained or lost an electron -usually have opposite charges a. Cation – an ion which has lost an electron, so positively charged. b. Anion – an ion has added an electron so it is negatively charged. 2) Compounds formed by ionic bonds –ionic compounds. Also called Salts. 3) Strength of ionic compounds is affected / influenced by the environment. Example: common table salt (NaCI) a. Dry – difficult to break. b. dissolved in warm water bonds are easy to break. b. COVALENT bonds 1) Formed when atoms share electrons. 2) Can be polar or non polar a. when non-polar – electrons are shared equally. b. when polar unequal sharing of electrons. One atom more electro negative than other.
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BIOLOGY FINAL
TERM
What % of DNA is made up of junk DNA? What Organelles and structures found only found only in animal cells What factors denature enzymes, proteins What group determines properties of amino acid? What happens to plant cells in hypotonic, hypertonic and isotonic solutions
DEFINITION
97% junk DNA
FROM LECTURE NOTES
Organelles/Structures found only in animal cells: contractile vacuole (resembles hub of a wheel and expels excess water), flagellum (for locomotion), lysosome, and centriole (involved in cell division)
Factors that denature enzymes/proteins: heat, salt concentration & pH concentration The R group determines the specific properties of an amino acid.
Water balance in plant cells: (1) hypertonic solution outside the cell – causes water to leave the cell; the cell may shrivel and die (called plasmolysis) (2) hypotonic solution outside the cell – water still enters cell; however, the cell will not burst because the plant cell wall prevents excess water buildup; this condition is termed turgid and is ideal for a plant (3) isotonic solution outside the cell – plant becomes flaccid and may wilt
What Organelles and structures found only plant cells What percent of cotton and soybean corps are genetically modified? What happens Animal cells in hypotonic, hypertonic and isotonic solutions
Organelles/structures found only in plant cells: chloroplast, chromoplast, leucoplast (stores starch granules), cell wall, central vacuole 74% soybean 71% cotton
Water balance in animal cells: (1) hypertonic solution outside the cell – causes water to leave the cell; the cell may shrivel and die (called crenation) (2) hypotonic solution outside the cell – causes water to enter the cell; the cell may take up so much water that it bursts (3) isotonic solution outside the cell – optimal solution; the plasma is isotonic to the red blood cells being transported in it
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BIOLOGY FINAL
TERM
Where does DNA replication occur in the cell and what generally happens in each process?
DEFINITION
DNA replication the DNA strand serves as a template used to make a complimentary strand; proceeds from a replication bubble • special proteins involved: (1) DNA polymerase – the enzymes that catalyze the elongation of DNA (a) the rate of elongation is 50 nucleotides per second (b) 11 different types of DNA polymerase are known (2) primase – an enzyme that initiates the “primer” for the synthesis of polynucleotides (3) helicase – an enzyme that unwinds the parental double helix (4) topoisomerase – an enzyme which corrects the strain of “overwinding” • there are numerous replication bubbles on the DNA strand • replication occurs in both directions a) toward the replication fork (called the leading strand) – the new or daughter strand is in one continuous piece b) away from the replication fork (called the lagging strand) – the daughter strand is in short pieces, called Okazaki fragments
FROM LECTURE NOTES
DNA replication (cont'd) (1) DNA ligase – an enzyme that fuses these fragments, “proofreads” them and has a repair function • Nucleotides are only added from the free 3’ end of the strand, never from the 5’ end • replication depends on specific base pairing • if a mistake is made in this replication, a mutation occurs (i.e. exposure to UV light or carcinogens can cause a mutation) 1) special enzymes will try to fix the mutation, such as: a) DNA polymerase b) DNA ligase c) nuclease (a cutting enzyme) 2) if these enzymes can’t fix the problem, the cell may self-destruct or become cancerous
Where does DNA transcription, occur in the cell and what generally happens in each process?
DNA transcription mRNA is synthesized on a DNA template (only one of the strands is used); in eukaryotes, this occurs in the nucleus Transcription Process: a. initiation – the start of RNA synthesis in which: 1) the DNA strand unwinds and separates 2) RNA polymerase attaches to the promoter 3) RNA polymerase reads the DNA strand and supplies the complementary bases, with uracil in place of thymine b. elongation 1) RNA elongates and the RNA strand peels away from the DNA template 2) strands of DNA come back together again c. termination – detachment of RNA polymerase from the terminator d. in eukaryotic cells: 1) mRNA is modified before it leaves the nucleus a) a cap and tail are added, which are composed of: (1) cap: G nucleotides (2) tail: 50-250 A nucleotides (3) these nucleotides are not translated into proteins b) function of cap and tail (1) facilitate the export of mRNA from the nucleus (2) protect mRNA from attack by cellular enzymes (3) help ribosomes bind to the mRNA c) the mRNA may be spliced, in which the introns will be removed and the exons spliced together (1) mRNA will then be a smaller single molecule (2) snRNA (small nuclear RNA) becomes involved – plays a structural and catalytic role d. finally, the mRNA leaves the nucleus to be translated
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BIOLOGY FINAL
TERM
Where does DNA translation, occur in the cell and what generally happens in each process?
DEFINITION
DNA translation 1. tRNA – transfer RNA; an interpreter a. composed of two parts in a clover-leaf shape: 1) anticodon – complementary to the code on mRNA; recognizes mRNA code by using the base pairing rules 2) an amino acid attachment site b. example of coding: anticodon UAC, mRNA code AUG 2. requirements for translation to occur a. mRNA b. tRNA with amino acids attached c. ATP for energy d. ribosomes 1) made up of RNA a) large subunit (1) binding sites for tRNA: P & A (2) exit site at E b) small subunit
FROM LECTURE NOTES
DNA translation (Cont'd) (1) binding site for mRNA c) subunits separate, but come together to form a fully functional ribosome 2) functions to bring mRNA and tRNA together 3. Process of translation a. initiation: tRNA binds to the start codon AUG on mRNA; the amino acid methionine is attached to the tRNA codon b. elongation 1) codon recognition: tRNA codon pairs with mRNA codon; this pairing occurs at the A site 2) peptide bond formation: tRNA with a polypeptide at the P site forms a bond with the tRNA polypeptide at the A site, then A site polypeptide detaches from P 3) translocation: a) P site tRNA moves to E site b) initial tRNA leaves the ribosome c) ribosome translocates (moves) the A site tRNA to the P site d) codon and anticodon are still bonded e) mRNA and tRNA move as one unit; this movement brings the next mRNA codon to the A site and the movement continues c. termination: the ribosome recognizes the stop codon and the polypeptide is terminated and released
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BIOLOGY FINAL
TERM
Hardy Weinberg Equilibrium
DEFINITION
1) was used to estimate the frequency of the PKU gene in the US population
FROM LECTURE NOTES
Hardy Weinberg Equilibrium – p2 +2pq+q2=1 (Law) 1. When a population is in equilibrium, there are no changes in allele frequency 2. A population is in equilibrium (not evolving) if: a. there is no gene flow b. there is no genetic drift c. there are no mutations d. mating is random e. there is no natural selection 3. functions of Hardy Weinberg: a. evolution is happening everywhere b. can be used to estimate allele frequencies in a population c. public health officials can use it to estimate how many members of a population are disease carriers
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BIOLOGY FINAL
TERM DEFINITION FROM LECTURE NOTES
REMEMER THERE WILL BE AROUND 5 QUESTIONS FROM THE "EVOLUTION OF ANTIBIOTIC…" CONNECTION The evolution of antibiotic resistance in bacteria is a serious public health concern Antibiotics are drugs that disable or kill infectious microorganisms. Most antibiotics are naturally occurring chemicals derived nom other microorganisms. Penicillin, for example, was originally isolated nom a mold and has been widely prescribed since the 1940s. A revolution in human health rapidly followed its introduction, rendering many previously fatal diseases easily curable (such as strep throat and surgical infections). During the 1950s, some doctors even predicted the end ofhuman infectious disease. Why hasn't this optimistic prediction come true? It did not take into account the force of evolution. In the same way that pesticides select for resistant insects (see Module 13.5), antibiotics select for resistant bacteria. The genes that confer such antibiotic resistance are often carried on R plasmids (see Module 10.23), which are passed on to bacterial offspring and may even be transferred to other bacteria. For nearly every antibiotic that has been developed, a resistant strain of bacterium has appeared within afew decades. For example, some strains of the hiberculosis-causing bacterium are now resistant to all three of the antibiotics commonly used to treat the disease. Figure 13.13 shows an X-ray of a TB patient. In what ways do we contribute to the problem of antibiotic resistance? Livestock producers add antibiotics to animalfeed as a growth promoter. As a result, much of the packaged meat for sale in supermarkets contains bacteria that are resistant to standard antibiotics. Doctors contribute to the problem by overprescribing antibiotics-for example, to patients with viral infections, which do not respond to antibiotic treatment. And patients contribute to this problem through the misuse of prescribed antibiotics-for example, by prematurely stopping the medication because they feel better. This allows mutant bacteria that may be killed mbre slowly by the drug to survive and multiply. Subsequent mutations in such bacteria may lead to full-blown antibiotic resistance. During the anthrax crisis of2001, public health officials urged panicked citizens to avoid unnecessarily taking ciprofloxacin (Cipro), the drug used to treat the deadliest form of anthrax infection, because doings could select for resistant bacteria. Difficulty in treating common human infections is a serious public health concern. Penicillin was effective against nearly all bacterial infections in the 1940s but is virtually useless today in its original form. New drugs have since been developed, but they continue to be rendered ineffective as resistant bacteria evolve. The medical community and pharmaceutical companies are engaged in an ongoing race against the powerful force of bacterial evolution.
Figure B.B Colorized X-ray of the lungs ofa tuberculosis patient (infection highlighted in red), with inset showing Mycobacterium tuberculosis. the infecting agent Web/CD Thinking as a Scientist Connection: What Are the Patterns of Antibiotic Resistance? R Explain why the following statement is incorrect: "Antibiotics have created resistant bacteria." The use of antibiotics bas increased the fiequency of alleles for resistance that were already naturally present in bacterial populations.. BIOLOGY Concept & Connection-- Fifth edition --pg272 NEIL A. CAMPBELL; JANE B REECE; MARTHA R. TAYLOR; ERIC J. SIMON
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