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171 Cards in this Set
- Front
- Back
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These four atoms make up 96% of all living things.
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C, N, O, H
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Describe the structure of an atom.
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Atoms are the building blocks of life. They are composed of three different subatomic particles, protons neutrons and electrons. Electrons orbit the protons and neutrons.
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The mass number is determined by the number of what two subatomic particles?
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The number of protons and the number of neutrons.
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Protons, neutrons and electrons carry what kind of charge?
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Protons are positively charged, electrons are negatively charged, neutrons have no charge.
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The type of atom is determined by the number of what sub atomic particle?
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The number of protons determines the mass number.
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How are electrons organized in atoms?
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A maximum of 2 on the innermost shell, and a maximum of 8 in each of the next two electron shells. They fill from the inside out, so first shell always fills before the second and the second always fills before the final shell.
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How are covalent bonds formed?
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They are formed from the sharing of electrons. A single covalent bond involves the sharing of two electrons
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In covalent bond the sharing of electrons are not always equal. What kind of molecule is created when this occurs?
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This creates a polar molecular. A molecule is non polar if the sharing of electrons is equal. Polar molecules have Os and Ns. O>N>C=H (O is more electro-negative than C). Polar molecules contain 2 atoms with unequal electronnegativity.
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What are ions? How are they formed?
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Ions are when covalent polar bonds go wrong. One molecule steals an electron from another molecule. The likelihood of an ion being created is based on the # of electrons in the outer shell.
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What are polar molecules?
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Polar molecules are hydrophilic (water loving) and non polar are hydrophobic
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Define cancer
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Cancer is a problem of normal cells dividing in situations in which they should not. Be able to explain how this happens as a result of mutations that a particular cell accumulates (from the environment, by chance, inherited etc)
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What is the cell theory?
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All living organisms are made up of cells. All cells come from pre existing cells.
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What happened in pasteurs experiment?
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Pasteur used a swan neck flask to demonstrate that all cells come from pre existing cells.
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What organelles do prokaryotic cells contain?
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Plasma membrane, cell wall, capsule(for added protection), DNA (in the nucleoid and plasmids), ribosomes, cytosol, flagella, fimbriae,cytoskeleton.
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What are some of the issues with Eukaryotic cells?
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Eukaryotic cells have issues with getting materials into the cell, this is because they are large. The SA:V ratio gets worse as the cell increases in size.
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What are the function of the following organelles and structures?
a. Nucleus, with nuclear membrane, nuclear pores and nucleolus b. ribosomes, both free and those that form part of the rough ER c. endoplasmic reticulum that is part of the rough ER d. Golgi e. secretory vesicles f. plasma membrane g. smooth ER h. lysosomes (mostly in animal cells) h. mitochondria i. vacuoles (in plants and fungi, but not animal cells) j. chloroplasts (in plants and algae, but not animal cells or fungi) k. centrioles l. peroxisomes m. cytoskeleton |
a. Nucleus, with nuclear membrane, nuclear pores and nucleolus
b. ribosomes, both free and those that form part of the rough ER c. endoplasmic reticulum that is part of the rough ER – for protein synthesis and initial stages of modification of proteins. d. Golgi (for protein modificatione.g., addition of sugars to proteins) e. secretory vesicles f. plasma membrane g. smooth ER (for lipid synthesis and detoxification) h. lysosomes (mostly in animal cells): the role of lysosomes as the recycling center of the cell; how materials end up in the lysosome by autophagy, phagocytosis and receptor-mediated endocytosis (be able to describe what each of these processes is, and know examples of each) h. mitochondria –the role of mitochondria in eukaryotes in making ATP; understand that prokaryotes do not have mitochondria but can make ATP (they use their plasma membrane instead). i. vacuoles (in plants and fungi, but not animal cells) j. chloroplasts (in plants and algae, but not animal cells or fungi) for photosynthesis k. centrioles (for organizing microtubules in animal cells, but not plant cells) l. peroxisomes (for reactions that generate hydrogen peroxide, which is broken down in peroxisomes) m. cytoskeleton (microfilaments, microtubules, and intermediate filaments) |
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How do proteins of the cell end up in the right compartments?
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the role of address tags or localization signals (a few amino acid sequences) on each protein, that direct the particular protein to it’s destination (except proteins destined for the cytosol have no localization signal). And the role of transport proteins that help proteins get to their correct destination, and the role of recognition proteins on the various organelles, which help proteins enter the correct organelle once they get there.
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What organelles are proteins passed through during synthesis?
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They start on the ribosomes then move to the ER, Golgi, lysosomes and secretory vesicles. The vesicles fuse with the plasma membrane and release the protein to the cell surface.
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Proteins for what organelles/structures are synthesized on free ribosomes?
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Cytosol, mitochondria, chloroplasts, peroxisomes and nucleus.
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What is the cytoskeleton composed of?
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Microfilaments and microtubules
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What are microfilaments composed of?
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They are composed of actin and include myosin motors.
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What are microtubules composed of?
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They are composed of the tubulin with dynein and kinesin motors.
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What are intermediate filaments used for?
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Intermediate filaments are used for cell strength (not movement). Defects in a gene that codes for intermediate filament protein leads to the disease (EBS). These individuals blister easily when exposed to minor trauma.
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Movement of organelles like chloroplasts, vesicles, and chromosomes occur on what two components of the cytoskeleton? How do they move around on them?
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Microfilaments and microtubules are used to transport organelles around the cell. They use motor proteins to do this.
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The movement of cells with pseudopods occurs through forces generated through the polymerization of what cytoskeleton component?
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Actin.
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What cytoskeleton element does the cell use to move with the flagella? How does the movement occur?
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Microtubules are used. Motor proteins are used to make the flagella move and move the entire cell.
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What is the diameter of microtubules, microfilaments
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Microfilaments are around 6nm in diameter. Microtubules are larger and are about 25nm in diameter (outer diameter).
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What is the polarity of the cytoskeletal elements?
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Microtubules have a + and - end . There are two different motor proteins that dynein and kinesin that can walk the protein. Intermediate filaments have no polarity (no motors). Microfilaments have only one motor protein because of their polarity.
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Membranes are composed of what? And where are they found?
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Membranes are composed of lipids and proteins, they are found around many organelles. (Chloroplasts, peroxisomes, lysosomes etc)
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Lipids are made up of what atoms? Are they polar or non polar?
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They are composed of mostly H and C. This makes them non polar and hydrophobic. O>N>C=H.
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What are the subunits of lipids?
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Isoprenes and fatty acids.
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What is the general structure of fatty acids?
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They are composed of Triglycerides and/or phospholipids. Has a carboxylic acid and a long tail.
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Fatty acids can vary based on what two variables?
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The length of their Hydrocarbon tail and the number and position of double bonds(if any).
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Some Fatty acids will have "kinks" in their hydrocarbon tail, what causes this?
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A carbon carbon double bond. This means that the fat is unsaturated.
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What is a saturated fatty acid?
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A fatty acid that has all carbon carbon single bonds. No extra hydrogen can be added to it.
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How do fatty acids attach to glycerol?
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Three fatty acids attach to glycerol to form a triglyceride. (this is a fat).
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What is it called when two fatty acids and a phosphate group bind to glycerol?
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This is called a phospholipid.
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What kind of reaction is the joining of fatty acids/ phosphate to glycerol.
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This is a condensation reaction. The reverse of this reaction is a hydrolysis reaction.
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What kind of charge does a phospholipid have?
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A phospholipid has a hydrophobic, non polar, tail and a hydrophilic head, polar, head.
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How do phospholipids arrange themselves in micelles and lipid bilayers?
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Because phospholipids have polar heads and non polar tails, they can arrange themselves in a way that has that the polar heads are facing inside the cell and outside the cell. While the tails are facing the tails from the other phospholipid.
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What molecules can cross the membrane most easily
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Small, non-polar molecule (hydrophobic), can pass the membrane most easily.
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What determines how permeable membranes are?
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The length of the hydrocarbon tails (shorter tails = more permeable). The presence of double bonds in the tails causes more permeability (larger spaces). Cholesterol makes the membrane less permeable (cholesterol will "stick" into the membrane and "clog" it).
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When will a molecule cross the membrane?
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They will cross the membrane if the membrane is permeable to that particular molecule and if there is a concentration gradient on either side of the membrane. (Unless there are protein pumps involved).
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When does water move across the membrane?
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Water moves across when there is more water on one side of the membrane(hypotonic) compared to the other side (hypertonic). When the water on the outside has the same concentration as the water on the inside the solutions are isotonic.
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What is an integral membrane protein? What is a peripheral membrane protein?
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Integral membrane proteins are proteins that exist in the actual membrane. Peripheral membrane proteins are temporary, they include ion channels.
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What kinds of amino acids are present in integral membrane proteins?
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Hydrophobic inner R groups and Hydrophilic outer R groups.
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What is the meaning of the fluid-mosaic model?
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This model describes the plasma membrane of animal cells. It says that there are two layers (a bilayer) of phospholipids.
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What is role of proteins in membranes?
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Proteins act as pumps/ receptors to move materials from a low concentration to a higher concentration (up the concentration gradient).
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What kinds of proteins are involved with facilitated diffusion?
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This is also know as passive transport, this requires no energy to work. Channels, ionophores, and transport proteins are involved with this. They move molecules from areas of high concentration to low.
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What is the difference between passive and active transport?
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Active transport(up concentration gradient) requires energy, passive transport does not require energy. Active transport uses pumps.
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What is the basic structure of nucleotides?
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CUT are pyrimidines, they contain one ring. AG are purines and have two rings groups. They are sugars attached to a phosphate group on one of the bases.
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What is the difference between DNA and RNA?
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RNA contains U instead of T. DNA has the sugar deoxyribose and RNA has the sugar ribose.
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How do nucleotides get added to each other in a polymerization reaction?
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DNAP polymerase joins nucleotides together. The reaction is a condensation reaction. Nucleotides are always added to the 3' end.
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Are nucleic acids polar?
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Nucleic acids have polarity, at the 5' end there is a phosphate and the 3' end there is a OH group.
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What does the structure of the DNA molecule look like?
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Double helix, with C-G, A-T pairing. Watson and crick were the first to describe the structure (in 1953).
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True/False Only purine and pyrimidine pairs can fit inside the DNA double helix.
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True
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How many bonds do A-T have? C-G? What kind of bonds are these?
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A-T has two hydrogen bonds. C-G has 3 hydrogen bonds.
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How does RNA structure differ from DNA structure?
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RNA is usually single stranded (Can become double stranded, with hair-pin structures, loop is where bases cannot pair).
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What is required for DNA replication with DNA polymerase?
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A template strand. A free 3' OH. An existing strand to continue synthesis from. (This means DNAP needs to start with an RNA primer).
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Where does dna synthesis being?
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The origin of replication. The strands separate into a bubble (with two replication forks). Synthesis is bidirectional. In eukaryotes there are multiple origins for DNA replication.
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How does DNAP work on replication forks?
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DNAP moves to the 5' end of the template. Synthesis is from the 5' end to the 3' end of the growing strand (nucleotides are added to the 3' end of growing strand).
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What are okazaki fragments?
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They are fragments of DNA made on the lagging strand. They work by synthesis only occuring on the 3' end, thus during replication with two origins of replication there is always a strand that needs to be synthesized with okazaki fragments.
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What happens in the process of DNA replication on the lagging strand?
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On the lagging strand RNA primers are removed, DNA synthesis begins to the point where DNA synthesis last left off. The remaining small gap is sealed with ligase.
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What is telomerase and why is it important?
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on the lagging strand, removal of the RNA primer at the end of the chromosome leads to a gap that cannot be filled by DNA replication. Telomerase is used to help replicate DNA at the ends of chromosomes (otherwise, chromosomes get shorter and shorter with each round of replication).
telomerase works by extending the TEMPLATE strand in the 5’ to 3’ direction (as usual), using it’s own RNA as template for this. Primase can then come in a make a new primer, using the extended template strand as template, and DNAP extends from the primer as usual (and removes the primer from the next Okazaki fragment). The gap is sealed with ligase as usual. |
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What is telomerase made up of?
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A short RNA molecule and a protein.
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What is proof-reading?
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DNA polymerase proof-reads, correcting the errors soon after making them. (This means DNAP has 4 activities, synthesis of DNA, removal of RNA primers, filling gaps between okazaki fragments and proof-reading).
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What is mismatch repair?
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Another method of DNA error repair. DNA errors are corrected by enzymes. The most methylated strand of DNA is the oldest, so this is compared to the strand with the least amount of methylation. The strand with the least amount of methylation is the one that is repaired.
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What can cause damage to DNA?
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UV light, chemicals etc.
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Individuals with Xeroderma pigmentosum lack what?
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They lack the enzyme to repair DNA, so these individuals are very sensitive to UV light. Colon cancer is also caused by a similar defect in repair enzymes.
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When is the mitotic cell cycle used?
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It is used to generate identical copies of existing cells. The division of cells from a fertilized egg.
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What is involved in the mitotic cell cycle?
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Making more cytoplasm, an additional copy of each chromosome then the division into two halves.
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What are the different phases of the cell cycle?
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Interphase (G1,S,G2) and mitosis(M). The final step is cytokinesis.
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What happens in G1, G2, S, and M phases?
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G1 and G2 there is cell growth. DNA synthesis occurs in S phase, chromosome separation occurs in M.
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Before mitosis happens what must occur?
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Cell size must increase, DNA must be replicated, the microtubule organizing center must also be seperated. (centrosome)
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What happens during prophase?
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Chromatin condenses into chromosomes.
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What happens during metaphase?
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Chromosomes align on metaphasic plate
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What happens during anaphase?
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Chromosomes seperate to different parts of the cell.
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What happens during telophase?
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Nuclear envelope is reformed. Cytokinesis usually occurs now.
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How is cytokinesis different in plant and animal cells?
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In plant cells the membrane is split, and a new cell wall is formed in the center of the cell. Another wall is formed in and the cells are then separated. In animal cells, the membrane is pinched to separate the cell into two cells.
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How do chromosomes move apart during mitosis?
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They use motor proteins on the microtubules. (ex dynein). And also through the disassembly of microtubules.
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What kinds of cell cycle controls are there?
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Promoters, that promote the division of the cell. (Eg MPF which is made from cyclin and kinase (CDK))
And checkpoints, that stop the division of the cell. |
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What kinds of checkpoint proteins are there and what do they do?
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G1 checkpoint( checks that there are adequate nutrients , cell size if sufficient, and DNA is not damaged).
G2-M checkpoint( checks that DNA is not damaged, and DNA has been properly replicated) M-phase checkpoint (two different checkpoints that first check if all chromosomes are attached to the mitotic spindle and the second checks that the chromosomes have separated correctly). If the conditions for cell division are not ok, the cell cycle stops at the check point and waits until conditions are ok in order to continue with the cycle. |
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What happens if there is a defect in a checkpoint protein?
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Cancer can form, chromosomes can get lost, faulty cells can be created.
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What are the steps in protein synthesis?
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Separation of double stranded DNA. Reading of the template strand by RNAP. mRNA is created. This needs to be processed by the ribosome and created into a protein now.
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How is RNA made?
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(a) synthesis is from the 3’ end of the template and therefore towards the 5’ end of the template (i.e., in the 5’ to 3’ direction on the growing strand); (b) the need for a single-stranded template. Differences from DNA synthesis are (a) no primer is necessary as RNAP does not need an existing strand to get started; (b) only one strand is used as template for any one gene; (c) U is used instead of T; (d) nucleotides have ribose instead of deoxyribose; (e) RNAP begins synthesis at the start of each gene, and ends at the end of each gene (DNAP ignores boundaries between genes).
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Where is RNA made in eukaryotic cells? Prokaryotes?Where does translation occur?
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RNA is made in the nucleus in eukaryotes. Translation occurs on free ribosomes in the cytoplasm. In prokaryotes transcription and translation occur in the same location at the same time.
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What does the the ribosome need to do to begin translation of the mRNA?
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The ribosome needs to bind to mRNA and read the nucleotides that code for amino acids. Initiation starts at the P site of the ribosome. The process continues and new amino acids are added into the A. Amino acids leave the ribosome through the E site. Peptide bonds hold together amino acids.
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What is the central dogma?
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DNA-->RNA--->proteins
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Why do codons need to have 3 nucleotides to code for 20 amino acids?
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Because having only two amino acids would result in 4*4 (16) possible amino acid combinations. Three amino acids results in 4*4*4 (64) possible combinations. This means that amino acids have multiple codons that code for them.
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How is transcription initiated in prokaryotes and eukaryotes?
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In prokaryotes sigma factor is used to bind to the promoter. In eukaryotes basal transcription factor is used to bind to the promoter. These factors allow RNAP to bind to the promoter.
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Transcription is terminated with what sequence?
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Termination sequence.
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What are the three RNA processing events must occur before mRNA can be translated?
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1. The introns must be removed by splicing and the exons are spliced together. This process is carried out by the sliceosome.
2. 5' cap must be added to the 5' end of mRNA, this allows the ribosome to recognize this RNA molecule for translation. 3. A 3' poly A tail must be added to the end of the mRNA , this prevents the mRNA from degrading. |
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What are the 3 major participants in translation?
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The mRNA, tRNA and ribosomes.
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What does mRNA do?
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It carries the code for the protein sequence. It is read from 5’ towards the 3’ direction.
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What does tRNA do?
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It is an adaptor molecule that can read nucleotides and direct incorporation of amino acids.
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What is a tRNA codon?
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The tRNA codon is a codon that is on the anti-codon loop of the tRNA. This codon sequence is the reverse of the sequence that the ribosome is current looking at.
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What end of the tRNA is the amino acid attached to? (5' or 3')
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The amino acid is attached to the 3' end.
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What determines the amino acid attached to the 3' end of the tRNA?
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The codon sequence on the mRNA.
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How does initiation (of translation) work?
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a. the small subunit of the ribosome binds at the 5’ end of mRNA, and then scans along for the first AUG.
b. at the P site, the ribosome then binds a tRNA with a methionine attached (the amino acid corresponding to the AUG) c. the large subunit of the ribosome binds, clamping the whole structure together |
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How does elongation (of translation) work?
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d. at the A site of the ribosome, the next charged tRNA (with its amino acid attached) binds to the ribosome.
e. a peptide bond forms between the two amino acids f. the bond between the first tRNA (at the P site) and methionine is broken, leaving the methionine attached to the amino acid that is at the A site. g. the ribosome moves down one codon, towards the 3’ end of the mRNA h. the empty (uncharged) tRNA leaves from the E site i. a new (charged) tRNA with associated amino acid binds to the ribosome at the empty A site j. the cycle continues (go to e again) |
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How does termination (of translation) work?
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a. Translation terminates when a stop codon is present at the A site. A release factor (a protein) that resembles a tRNA in size, shape and charge, enters the A site, and catalyzes the release of the polypeptide chain from the tRNA to which it is attached (i.e., at the P site).
b. The two subunits of the ribosome fall apart, the release factor is released, the mRNA is released, and the tRNAs are released. These components of the translation machinery can all then be used again. |
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Proteins are made up of how many different amino acids?
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20
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What is the general formula for an amino acid?
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NH2CHRCOOH
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What does the ionized form of an amino acid do to the amino acid?
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It makes it hydrophilic
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Acidic amino acids are?
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Polar and hydrophilic
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Basic amino acids are?
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Non-polar and hydrophobic
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How is a peptide bond formed?
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It is formed when the carboxyl group bind with the amino group. H20 is released when this bond is formed.
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True or False
Energy is required to form peptide bonds? |
True
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What is the N-terminus and C-terminus on the poly peptide chain?
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the NH3 is the N-terminus and the COO- is the C terminus
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How are amino acids numbered in a protein
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From the N-terminus to the C-terminus
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What are the four levels of structure in proteins?
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Primary, Secondary, Teritary, Quaternary
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What is the primary structure?
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A sequence of amino acids
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What is the secondary structure?
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Alpha helix and beta-pleated sheets, involving H-bonds between O’s and H’s on either side of the peptide bond (not with each other – with H’s and O’s from other peptide bonds). R groups are NOT involved.
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What is the tertiary structure?
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Interactions between multiple alpha helixs and beta-pleated sheets to form the overall shape of the protein, involving R groups interacting with each other as well as with O’s and H’s on either side of the peptide bond .
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What is the quaternary structure?
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Interactions between more than one polypeptide chain, involving the types of interactions used in tertiary structure, but between different polypeptide chains. These are multiple tertiary structures put together.
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What does it mean to have a denatured protein?
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A denatured protein is a protein that once had a structure (Beta- pleated sheet, poly peptide chain, quaternary structure etc) but was exposed to some kind of outside force.
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What is activation energy?
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The amount of energy needed to be added into a chemical system for a reaction to occur.
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What is the transition state?
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It is when a molecule is no longer a substrate but not yet the product. Occurs at the peak of the activation energy graph.
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What are reactants/ substrates?
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Reactants /substrates are what is put into a enzyme reaction.
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What are products?
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What the substrate/reactant is transformed into after an enzyme reaction
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What is the active site?
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A "port" on an enzyme where substrates can bind to and undergo a chemical reaction.
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What is the meaning of the term exergonic?
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Exergonic is a kind of reaction where the free energy of the products is less than the free energy of the substrates/reactants.
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What is the meaning of the term endergonic?
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Endergonic is a kind of reaction where the free energy of the products is more than the free energy of the substrates/reactants.
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What is a competitive inhibitor?
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A competitive inhibitor is a inhibitor that binds to the active site of an enzyme and prevents reactions on that enzyme.
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When are gametes made?
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Gametes are made during meiosis. (eg sperm and egg). Once sperm and egg combine, further cell division is done using mitosis.
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What is the meaning of the term diploid?
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Two sets of chromosomes (in humans half from sperm and half from egg). This is also referred to as 2n.
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What is the meaning of the term haploid?
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One set of chromosomes. These are the sex cells (gametes) in humans. This is also referred to as n. Two haploids(n) will combine to make diploid(2n).
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What happens just before mitosis or meiosis being?
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Chromosomes are duplicated by DNA synthesis and the centrosomes are also duplicated.
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What happens in meiosis during prophase I?
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In Prophase 1 everything from mitosis prophase occurs with the addition crossing over. This leads to exchanging genetic information.
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What happens in meiosis during metaphase I?
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The chromosomes line up on the spindle.
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What happens in meiosis during anaphase I?
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Sister chromosomes stay together when separating to different poles. Non sister chromosomes separate.
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What happens in meiosis during Telophase I?
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The chromosomes detach from the spindle and the spindle disintegrates.
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What happens in meiosis during Prophase II?
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A new spindle is created, the chromosomes attach to the spindle.
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What happens in meiosis during Metaphase II?
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Chromosomes lineup on the metaphase plate in the center.
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What happens in meiosis during Anaphase II?
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The sister chromatids separate.
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What happens in meiosis during Telphase II?
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Nuclear envelope reforms, nucleolus reappears, chromatids de condense and the spindle disintegrates. Cytokensis occurs. At this point there should be 4 gametes created.
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What are the differences between mitosis, meiosis I and meiosis II?
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The most important difference is that during prophase I of meiosis, homologous chromosomes (homologs) are paired up, and crossing-over occurs between chromatids belonging to different homologs; at metaphase I, the chromosomes line up on the metaphase plate in pairs (whereas in mitosis they do not pair up during prophase and they are all arranged in a straight line at metaphase). During anaphase I, the homologs separate from each other (whereas during mitosis and anaphase II, sister chromatids separate from each other). Then at telophase, one homolog is at each pole. When the cells enter meiosis II, two spindles are formed, and each spindle at metaphase II has chromosomes lined up as in mitosis (but just one of each homolog).
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How do meiosis and mitosis differ in the number of chromosomes present in the cells produced from each.
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Meiosis has half the number of chromosomes (n). Mitosis has 2n (diploid).
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Why did Mendel work with peas?
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They were easy to cultivate, they have a short life cycle and it is easy to spot differences in the pea plants.
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What is a test cross?
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A cross between a two organisms with different genotypes. It is used to determine which one is dominant.
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What is the difference between genotype and phenotype?
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Phenotype is the physical appearance and expression of a genotype, which is heritable information .
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In pedigrees, boxes, circles, filled in boxes/circles, unfilled boxes and circles are what?
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Boxes represent males, circles are females, filled in boxes/circles are affected males or females, unfilled boxes/circles are unaffected males or females.
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What is the difference between autosomes and sex chromosomes?
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Autosomes are somatic. Sex chromosomes determine the sex of the individual.
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What is the role of carbohydrates?
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The roles of carbohydrate in the body includes providing energy for working muscles, providing fuel for the central nervous system, enabling fat metabolism, and preventing protein from being used as energy. Carbohydrate is the preferred source of energy or fuel for muscle contraction and biologic work.
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What is the general structure of a carbohydrate?
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(CH2O)n
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What do each monosaccharide contain?
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A double bond between C and O (C=O), some OH's and some CH's.
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How are the C atoms numbered in monosaccharides? /how are monosaccharides classified?
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Monosaccharides can be classified by the number x of carbon atoms they contain: diose (2) triose (3) tetrose (4), pentose (5), hexose (6), heptose (7), and so on.
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How do monosaccharides join together in a polymerization reaction?
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They join together in a condensation reaction. Two monosaccharides joining together make a disaccharide. Any additional monosaccharides added and it becomes a polysaccharide.
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What are some examples of monosaccharides and polysaccharides?
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A monosaccharide is Maltose. A polysaccharide is glycogen, cellulose and starch. Animals convert glucose into glycogen and plants convert glucose into starch.
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What is ATP and how is it used?
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ATP is the cells energy currency. Energy is used in ATP by hydrolysis and ATP synthase. These create ADP + Pi and heat energy.
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How is ATP made from glucose?
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It is made from glycolysis, pyruvate processing, the krebs cycle and the Electron transport chain.
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What is glycolysis?
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It is the breakdown from glucose ( a 6C molecule ) to two 3C molecules(pyruvate). This occurs in the cytosol and generates ATP and NADPH.
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What is pyruvate processing?
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The transport of pyruvate into the mitochondrial matrix and the conversion to acetyl CoA(2C) and Co2, with generation of NADH.
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What is the Krebs cycle?
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The break down of acetyl CoA into carbon dioxide in the mitochondrial matrix to generate ATP, NADH and FADH2.
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What is the electron transport chain?
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A chain in the inner mitochondrial membrane that takes on high-energy electrons from NADH and FADH2 and transfers them down the chain. The final electron acceptor is O2(this generates H20). When the electron moves down the chain energy is lost at every hand off, this lost energy is used to pump protons across the inner membrane of the mitochondria(matrix) out to the inner-membrane space. A buildup of protons occur in the inner-membrane space, this proton gradient is used to generate ATP by allowing the protons the flow back through ATP synthase. This flow through ATP synthase (which sits on the inner-membrane) causes ATP to be created. ADP + Pi =ATP
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What happens when there is no final electron acceptor in the ETC?
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Fermentation occurs. Only ATP and NADH can be made from glycolysis . Pyruvate is converted into lactic acid or ethanol (yeast) instead of entering the Kreb's cycle. The purpose of this is to regenerate NAD+. This allows glycolysis to occur again, not much ATP is made this way but some is better than none.
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How are anaerobic organisms different?
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Anaerobic(without oxygen) organisms are different because they don't need O2 as the final electron acceptor in the ETC.
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What structures are chloroplasts composed of?
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Two membranes, the inner and outer. Thylakoid membrane, thylakoid lumen. The stroma (soupy stuff that surrounds the thylakoids). A stack of thylakoids is referred to as a granum.
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What is the purpose of photosynthesis?
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To use harness solar energy and convert it to a form useable by the cell.
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What are the two pigments in the thylakoid membrane?
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Chlorophyll and Carotenoids.
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What are two common structures shared by both photosystem I and photosystem II?
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The antenna complex and the reaction center.
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How is light absorbed in PSI and PSII?
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Light is absorbed by pigments in the antenna complex. That energy in the form of a high energy electron is then transferred to the reaction center. The high energy electron is transferred to an electron acceptor which allows it to be passed down an ETC.
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How are PSII and cellular respiration similar?
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They both involve the pumping of protons. In PSII protons are pumped into the lumen of the thylakoid from the stroma. Also the use of ATP synthase to create ATP from ADP and Pi.
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How is PSI different from PSII?
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Electrons coming down the electron transport chain in PSI are used to convert NADP+ and H+ to NADPH. No pumping of protons is done in PSI.
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How are PSII and PSI connected to each other?
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PSII comes first. The electron from the ETC of PSII is given to PSI (the same electron is used). Electrons from the splitting of water (into oxygen, H+ ions and electrons) are used to replenish the electrons lost from PSII.
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Where do light independent reactions occur and what are they?
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Light independent reactions occur in the stroma and convert carbon dioxide to glucose.
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What molecules created in light dependent reactions are used in the light independent reactions?
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ATP and NADPH are used in the conversion of CO2 into glucose.
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What is the most abundant enzyme on earth? What is it used for?
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Rubisco. It is used in the Calvin cycle to convert C02 to glucose.
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What steps are involved in the Calvin Cycle?
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Going from rublose bisphospate (5C) to 3-phospho glycerate in the presence of C02. then ATP and NADPH (generated in PSI and II) are used to convert 3-phosphoglycerate to glyceraldehyde 3-phosphate; one out of 6 of these molecules is used to make glucose and fructose; the other 5/6 molecules of glyceraldehyde 3-phosphate are used to go back to ribulose bisphosphate, using more ATP from PSII. The whole point of this cycle is to convert CO2 to glucose, using energy that originally came from the sun.
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How do plants use glucose and fructose made during photosynthesis?
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They make disaccharide sucrose for transport around the cell, and use starch for storage of glucose
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What is glucose used for?
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Glucose is a way to temporarily store energy from the sun, until the cell is ready to convert glucose to CO2 and retrieve the energy locked up in glucose.
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