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52 Cards in this Set
- Front
- Back
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What is an Autotroph
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An organism that can harvest the energy of sunlight through photosynthesis, or other biological process to obtain chemical energy.
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What is a Heterotroph
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An organism that relies on the organic compounds produced by other organisms.
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What type of organism makes up 95% of all organisms on earth?
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Heterotrophs
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How do electrons transfer energy?
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An electron moves into the excited state by absorbing energy, moving it further from the nucleus. When an excited electron is transferred in a chemical reaction, some of the energy goes with it, the rest released as heat.
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What types of bonds store energy? What types of macromolecules have these high energy bonds?
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Carbon-Hydrogen bonds and Carbon-Oxygen bonds store energy. These bonds typically most effective in carbohydrates and lipids.
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Where does Glycolysis occur?
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In the cytoplasm.
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NADH is the _____ agent? It is also an electron ______?
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Reducing agent, electron acceptor
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What is the net gain of ATP from glycolysis?
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Net gain of 2 ATP
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What are the products of Glycolysis?
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2 NADH, 2 ATP, 2H20 and 2 Pyruvate
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Where is pyruvate oxidized?
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Inside the mitochondria, only after ATP is expended to bring it there.
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How many calories are released by the catabolism of glucose to CO2 and H2O
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Under cellular conditions, the change in free energy is as much as -720kcal/mol (-3012kJ/mol).
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What is β-oxidation?
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The breakdown of fats into two-carbon acetyl groups to combine with coenzyme-A to enter the Kreb's cycle
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What is deamination?
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The emission of the amino group as urea during the catabolism of proteins.
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What happens to a deaminated protein?
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It is converted into a molecule that enters glycolysis or the Kreb's cycle.
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What is the best energy storage molecule?
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Lipids.
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List the metabolites of glycolysis, in order.
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Glucose, Glucose 6-phosphate, Fructose 6-phosphate, Fructose 1,6-biphosphate, Glyceraldehyde 3-phosphate (G3P), 1,3-Biphosphoglycerate (BPG), 3-phosphoglycerate (3PG), 2-phosphoglycerate (2PG), Phosphoenolpyruvate (PEP), and Pyruvate
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Describe the glycolytic pathway.
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The first five reactions convert a molecule of glucose into two molecules of G3P. The second five reactions convert each G3P into pyruvate
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Describe the catabolism of carbohydrates.
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Glucose is oxidized into pyruvate, which is oxidized into acetyl CoA, which enters the Kreb's cycle.
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Describe the catabolism of lipids.
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Lipids are broken down into fatty acids and glycerol. The fatty acids undergo β-oxidation creating acetyl groups that react to form acetyl CoA for the Kreb's cycle.
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Describe the catabolism of proteins.
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Proteins are broken down into their primary structure, their amino acid sequence. They then undergo deamination, emitting an amino group as urea. The remaining carbon chain is converted into a molecule that enters glycolysis or the Kreb's cycle.
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What are the two ways to regenerate NAD+?
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When NADH is oxidized by NADH dehydrogenase in the electron transport chain, and when lactic acid is fermented by lactate dehydrogenase in muscle cells.
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What are the three complexes of membrane proteins
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NADH dehydrogenase, bc1 complex, and cytochrome oxidase complex
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What is dimerization?
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The autophosphorylation of receptor tyrosine kinases (RTKs).
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What are the three kinds of cell surface receptors?
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Chemically gates ion channels, enzymatic receptors, and G protein-coupled receptors.
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What is a chemically gated ion channel?
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A cell surface receptor that has a pore that opens when stimulated by the proper ligand allowing for the flow of the appropriate ion.
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What is an enzymatic receptor?
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A cell surface receptor that binds to the proper ligand extracellularly and catalyzes its response intracellularly.
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What is a G protein-coupled receptor?
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A cell surface receptor that causes GTP to bind to a G protein, and the new molecule delivers the signal inside the cell.
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What are the four main types of cell signaling?
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Direct contact, paracrine signaling, endocrine signaling, and synaptic signaling.
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What is direct contact signaling?
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When two cells in direct contact with each other send signals across gap junctions.
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What is paracrine signaling?
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When one cell secretes a ligand that only effects cells in the immediate area.
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What is endocrine signaling?
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When one cell secretes hormonal ligands that are released into the circulatory system to be carried to target cells.
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What is synaptic signaling?
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When a neuron releases signal ligands called neurotransmitters across a small synaptic gap to the target cell.
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What is a kinase?
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A class of enzyme that adds phosphate groups from ATP to proteins.
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What is a ligand?
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A signaling molecule.
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What is a phosphatase?
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A class of enzyme that removes phosphate groups from proteins.
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A reaction that isn't spontaneous is called a _______ reaction.
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An endergonic reaction.
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A reaction that is spontaneous is called a _______ reaction.
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An exergonic reaction.
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What is a connexon?
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A complex of six identical transmembrane proteins assembled in a circle that, when aligning with another cell's connexon, creates a communicating junction.
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What is a communicating junction?
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When two cell's connexons align perfectly allowing for the transport of small molecules or ions.
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What is an anchoring junction?
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When a cell mechanically attaches the cytoskeleton of a cell to the cytoskeletons of other cells or to the extracellular matrix, binding them together.
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What is a tight junction?
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When two cells line up, allowing for their plasma membranes to interlock, forming a sheet.
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What do glycolipids do?
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They serve as cell identity surface marker that are responsible for A, B and O blood types
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Describe the interphase.
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The interphase is composed of three parts, G1, S and G2. It is the preliminary step to mitosis. During G1, the primary growth phase, the cell is prepped for DNA synthesis. During S, the genome is replicated. During G2, the organelles are replicated and the cell is prepped for mitosis.
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What are the five steps of mitosis.
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Prophase, prometaphase, metaphase, anaphase, and telophase.
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Describe the prophase.
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Chromosomes condense into sister chromatids, the nuclear envelope breaks down, the cytoskeleton disassembled; the spindle begins to form, and the Golgi and ER are broken down.
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Describe the prometaphase.
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Following the breakdown of the nuclear envelope, the sister chromatids are connected to microtubules at the kinetochore by both poles. The chromatids are moved to the center.
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Describe the metaphase.
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Occurs when the chromatids are lined up at the center of the cell on an invisible axis called the metaphase plate. These chromatids are under tension by opposite poles.
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Describe the anaphase.
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The actual separation of the sister chromatids as the proteins holding them are degraded. Individual chromsomes move towards the poles by the shortening of the microtubule chain, and the movement of the poles further away from the center of the cell caused by microtubules sliding past one another, elongating the cell.
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Describe the telophase
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The reverse of the prophase. A new nuclear envelope is formed around each set of chromosomes. The chromosomes uncoil into a less dense form to allow for gene expression. Organelles like the Golgi and ER reform.
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Describe cytokinesis.
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A belt of actin forms around the circumference of the cell. As this belt constricts and tightens, the actin filaments slide past one another. This creates a cleavage furrow, which continues to tighten until the cells are separated.
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What is a kinetochore?
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A disklike protein structure that forms on a chromosome's centromere serving as an attachment site for microtubules.
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What is a centromere?
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A point of constriction on the chromosome that is the site for the binding of certain proteins.
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