Photosynthesis, Cellular Respiration, and Fermentation, Exams of Advanced Education

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MTTC Integrated Science - Life Sciences Part 1 Who uses photosynthesis? - Answer- autotrophs Where does photosynthesis occur? - Answer- chloroplasts chemosyntheis - Answer- used by prokaryotic autotrophs as an inorganic chemical reaction to produce energy heterotrophs - Answer- require food and use cellular respiration to release energy from chemical bonds in the food who uses cellular respiration to release energy from stored food? - Answer- all organisms light capturing events - Answer- The first stage in photosynthesis; thylakoids found in the chloroplasts capture light energy and produce excited electrons light-dependent reactions - Answer- convert light energy and water into ATP, NADPH, and O2 by the way of moving excited electrons in the stroma of plant cells Light Independent Reactions - Answer- Use ATP and NADPH (from the light-dependent reactions) plus CO2 to produce carbohydrate sugars photorespiration - Answer- a wasteful process that uses energy and decreases sugar synthesis that occurs in plants during photosynthesis. It occurs when the enzyme rubisco binds to oxygen instead of atmospheric CO2. How do C4 plants minimize photorespiration? - Answer- The light reactions and the Calvin cycle occur in different cells, so oxygen does not come into contact with rubisco. How do CAM plants minimize photorespiration? - Answer- Stomata are only opened at night, storing carbon dioxide in malate. During the day the carbon dioxide is released for photosynthesis. how do C3 plants minimize photorespiration? - Answer- They don't. They have no special adaptations to do so. This is more than 85% of plants! aerobic respiration - Answer- Respiration that requires oxygen. a series of enzyme- controlled reactions in which oxygen + glucose -> CO2 + H2O + energy (ATP). aerobic respiration occurs in a series of 3 reactions. what are they? - Answer- 1) glycolysis 2) the Krebs cycle 3) the electron-transport system Glycolysis - Answer- the breakdown of glucose by enzymes, releasing energy (2 ATP molecules), pyruvic acid (2 molecules), and NADH (2 molecules). Krebs Cycle (Citric Acid Cycle) - definition - Answer- a metabolic pathway in which the bonds of glucose (and occasionally fats/lipids) are broken down and reformed into ATP. Krebs cycle - the actual cycle - Answer- Acetyl CoA -> citric acid -> isocitric acid -> ketoglutaric acid (with amino acid and CO2 products) -> succinyl CoA -> succinic acid - > fumaric acid -> malic acid -> oxaloacetic acid electron transport chain - Answer- electrons are transported from enzyme to enzyme until they reach a final acceptor, including a series of RedOx molecules involved in the release of energy Fermentation - Answer- An anaerobic (without oxygen) cellular process in which glucose is only partially broken down and energy is released through the oxidation of sugars or other organic molecules. How is fermentation different from cellular respiration? - Answer- it uses neither Krebs cycle nor electron transport chains, and the final acceptor in fermentation is an organic molecule. which is more efficient: fermentation (an anaerobic respiration) or aerobic respiration? - Answer- aerobic respiration homolactic fermentation - Answer- produces lactic acid only heterolactic fermentation - Answer- produces lactic acid and other compounds lactic acid fermentation - Answer- - breakdown of glucose and 6-carbon sugars into lactic acid to release energy - anaerobic process (does not require oxygen) - can occur in muscle cells - performed by streptoococcus and lactobacillus bacteria - the type of fermentation in yogurts and foods alcohol fermentation - Answer- - breakdown of glucose and 6-carbon sugars into ethanol and CO2 to release energy - anaerobic process (does not require oxygen) - performed by yeast bacteria outer membrane of mitochondria - Answer- has proteins called porins that let small molecules through intermembrane space of mitochondria - Answer- space between inner and outer membranes inner membrane of mitochondria - Answer- contains proteins that aid in the synthesis of ATP Ribosomes - Answer- protein factories that translate the code of DNA into proteins by assembling long chains of amino acids. mRNA - Answer- messenger RNA; used by the ribosome to generate a specific protein sequence tRNA - Answer- transfer RNA; type of RNA that carries amino acids to the ribosome Golgi apparatus - Answer- stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum into containers called vesicles Cytoskeleton - Answer- A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement the three steps of the cell cycle - Answer- interphase, mitosis, cytokinesis Interphase - Answer- first step of the cell cycle, and the longest step of the cycle. the cell spends 90% of its time in interphase. has 3 substeps: 1) G1 phase (the first growth phase) 2) S phase (synthesis phase) 3) G2 phase (the second growth phase Mitosis - Answer- the asexual process of cell division where one parent cell divides into 2 identical daughter cells. used for growth, repair, and replacement of cells. has 4 substeps: 1) prophase 2) metaphase 3) anaphase 4) telophase prophase (4 things happen) - Answer- spindle fibers appear. DNA is condensed and packaged as chromosomes, nuclear membrane breaks down, and the nucleolus disappears metaphase (2 things happen) - Answer- spindle apparatus is formed, centromeres of the chromosomes line up on the equatorial plane anaphase (2 things happen) - Answer- centromeres divide, the 2 chromatids separate and are pulled toward opposite poles of the cell telophase (3 things happen) - Answer- spindle fibers disappear, the nuclear membrane reforms, and the DNA in the chromatids is condensed Cytokinesis - Answer- the dividing of the cytoplasm and cell membrane by the pinching of the cell into 2 new daughter cells. the actin filaments in the cytoskeleton form a contractile ring that narrows and divides the cell. eventually the contractile ring narrows down to the spindle apparatus that joins the two cells, and the cells eventually divide. cytokinesis in plant cells - Answer- cell plate forms Cytokinesis in animal cells - Answer- cleavage furrow forms Meiosis - Answer- a type of cell division where the number of chromosomes is reduced by 1/2. it produces gametes (egg and sperm cells) and has 2 stages: 1) meiosis I (the first mitotic division) 2) meiosis II (the second mitotic division) meiosis I - Answer- the cell replicates its DNA in interphase then continues through prophase I, metaphase I, anaphase I, and telophase I. At the end there are 2 daughter cells each with the same # of chromosomes as the parent cell. meiosis II - Answer- the cell enters a brief interphase but does NOT replicate its DNA, and then continues through prophase II, metaphase II, anaphase II, and telophase II. During prophase II the unduplicated chromosomes split, therefore, at the end there are 4 daughter cells each with 1/2 the # of chromosomes as the parent cell. what 3 things are checked at the cell checkpoints? - Answer- 1) is the cell dividing properly at each stage? 2) is this the appropriate time for division? 3) has the cell been damaged at all? Checkpoint One - Answer- called "restriction" in animal cells occurs at the end of G1 phase cell may decide to rest at this checkpoint (G0 phase) driven by cyclin D (CDK4) and cyclin E (CDK2) Checkpoint Two - Answer- occurs at the end of G2 phase driven by cyclin A (CDK2) Checkpoint Three - Answer- occurs during metaphase of mitosis checks that the chromosomes are lined up on the equatorial plane as well as the common 3 things driven by cyclin B (CDK1) point mutation - Answer- changes in a single nucleotide in a DNA sequence. there are 3 types: 1) missense 2) silent 3) nonsense missense point mutation - Answer- result in a codon for a different AA silent point mutation - Answer- result in a codon for the same AA as the original sequence nonsense point mutation - Answer- insert a premature stop codon, typically resulting in a nonfunctional protein frameshift mutation - Answer- mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide, resulting in the formation of a new protein product inversion mutation - Answer- A mutation involving a piece of a chromosome that breaks off and reattaches in reverse orientation. somatic mutation - Answer- occur in body cells such as bone cells, liver cells, or brain cells after conception. cannot be passed from parent to offspring. may cause cancer, disease, or they may be silent. germine mutation - Answer- found in germ (sperm and egg) cells and are present at conception. may be passed from parent to offspring and infected offspring will have 100% cell mutation. may cause diseases, or may be silent. spontaneous mutation - Answer- not caused by mutagens, but can occur in DNA due to molecular decay Mutagens - Answer- physical and chemical agents that interact with DNA to cause mutations. they are usually external factors. examples: - UV radiation - X-ray radiation - gamma radiation - viruses -microorganisms - asbestos - coal tar - tobacco - benzene - alcohol Embrylogy as evidence for evolution - Answer- the stages of embryonic development reveal similarities between different species, pointing back to the common ancestor theme. endosymbiosis theory - Answer- The theory that the eukaryotic cell evolved via the engulfing of one prokaryotic cell by another, forming the mitochondria and the chloroplasts of eukaryotic cells. evidence for the endosymbiosis theory - Answer- 1. Mitochondria and chloroplasts contain circular DNA (similar to bacterial DNA) 2. Mitochondria, chloroplasts and nuclei have double membranes 3. Mitochondria and chloroplasts are about the same size as bacteria cells 4. Infolding is known to occur in prokaryotic cells and probably gave rise to endoplasmic reticulum 5. Mitochondria are analagous in structure and function to purple bacteria as chloroplasts are to green/photosynthetic bacteria convergent evolution - Answer- Process by which unrelated organisms independently evolve similarities when adapting to similar environments divergent evolution - Answer- evolution of one or more closely related species into different species; resulting from adaptations to different environmental conditions (ex: adaptive radiation, wooly mammoth turned modern elephant) Speciation - Answer- Formation of new species fossil record as evidence for evolution - Answer- 1) fossils from rock layers from all over the world have been compared, enabling scientists to form a geologic timeline for the history of all living things 2) transitional fossils show the intermediate states between ancestral forms of organisms and the forms of the modern descendants, showing the path for evolutionary change 3) fossils exhibit homologies (similarities) with modern organisms Cephalization - Answer- the concentration of nerve tissue and sensory organs at the anterior end of an organism. literally the development of a head. Mutlicellularity - Answer- single-celled organisms gave rise to biofilms, which gave rise to multicellular organisms, which gave rise to all of the major phyla of multicellular organisms present today. Biosphere - Answer- part of Earth in which life exists including land, water, and air or atmosphere components of biosphere from smallest to largest... - Answer- organisms, populations, communities, ecosystems, biomes. Population - Answer- A group of individuals that belong to the same species and live in the same area Community - Answer- All the different populations that live together in an area Ecosystem - Answer- biological communities and their physical environment. Biomes - Answer- several ecosystems grouped together to form one large geographic biome Species - Answer- A group of similar organisms that can breed and produce fertile offspring. intraspecific community interactions - Answer- occur between members of the same species interspecific community interactions - Answer- occur between members of different species Biodiversity - Answer- the variety of life in the world or in a particular habitat or ecosystem. carrying capacity - Answer- Largest number of individuals of a population that a environment can support Symbiosis and its 3 types - Answer- A relationship in which two different organisms live in close association with each other 1) parasitism 2) commensalism 3) mutualism Parasitism - Answer- A relationship between two organisms of different species where one benefits (the parasite) and the other is harmed (the host) ex: tick and dog Commensalism - Answer- A relationship between two organisms in which one organism benefits and the other is unaffected ex: remora and sharks Mutualism - Answer- A relationship between two species in which both species benefit ex: rhino and tick birds Predation - Answer- An interaction in which one organism (predator) kills another (prey) for food. Territoriality - Answer- Defense of a space against encroachment by other individuals. altruism - Answer- a self-sacrificing behavior in which an individual animal may live to serve or protect another animal ex: honeybees, naked mole rats producers store about ____% of the solar energy they receive - Answer- 1% each successive level in the energy flow diagram only uses about ___% of the energy of the previous level - Answer- 10% Water Cycle (Hydrologic Cycle) - Answer- The continuous movement of water on, above, and below the surface of the Earth. carbon cycle - Answer- The organic circulation of carbon from the atmosphere into organisms and back again nitrogen cycle - Answer- The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere phosphorous cycle - Answer- the cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment. the slowest of all the cycles.