BIOS 242 Exam 2 Complete Term Questions And Answers

Organic Nutrient - ANS An organism that contains carbon and hydrogen Inorganic Nutrient - ANS An organism that does not contan carbon and hydrogen Phototroph - ANS An organism that gains energy from light through photosynthesis Heterotroph - ANS An organism that must obtain carbon in an organic form - they are dependent on other life forms Chemotroph - ANS An organism that gains energy from chemical compounds - this means they eat things. Harvesting energy from the things they eat. Autotroph - ANS An organism that gets its source of carbon from carbon dioxide an iorganic carbon source - referred to as the "self feeder"; They are NOT nutritionally dependent on other living things Photoautotroph - ANS An organism that gains its energy from light rays and its carbon source from CO2 in the air Examples of a photoautotroph? - ANS Photosynthetic organisms - algae, plants, Cyanobacteria What kind of organism is the basis of most food webs? - ANS Photoautotrophs Chemoautotroph - ANS An organism that gets its energy from eating things and gets its carbon source from inorganic compounds Examples of a Chemoautotroph - ANS Only certain bacteria/archaea - methanogens, deep-sea vent bacteria Lithoautotroph - ANS gets energy from inorganic materials - can actually digest rocks Chemoheterotrophs - ANS derive energy from chemical energy in the food consumed; carbon source also comes from the food consumed What are humans classified as? - ANS Chemoheterotrophs Aerobic Respiration - ANS the principal energy-yielding pathway in where the final electron acceptor in the electron transport chain is oxygen (O2) Osmosis - ANS movement of water across a permeable membrane Simple Diffusion - ANS The movement of molecules from a higher concontration to a lower concentration Facilitated Diffusion - ANS a molecule binds to a specific carrier protein that changes the shape of the cell and carries the molecule across the membrane Active Transport - ANS uses ATP to transport things into the cell against the concentration gradient Group Translocation - ANS form of active transport that couples a transport of a nutrient with its conversion to another form Permeases Pumps: - ANS these structures pump things in and out of the cell - most of the time its waste going out of the cell Endocytosis - ANS The transport of large molecules cell via the vacuoles enveloping or swallowing the molecules into the cell for further digestion Exocytosis - ANS The opposite of endocytosis - releasing whatever is in the vacuole out of the cell Phagocytosis - ANS the ingestion of solid matter into the cell like bacteria or another cell Pinocytosis - ANS the ingestion of liquid matter into the cell Cardinal Temperatures - ANS the range of temperatures for the growth of a given microbial species Psychrophile - ANS a microbe that can grow and reproduce in low/cold temperatures - optimal temp is 15 degrees celsius Mesophile - ANS a microbe that best at moderate temperatures - optimal temp is 20-40 degrees celsius Examples of Mesophiles - ANS Humans and pathogens Thermophile - ANS A microbe that thrives at relatively high temperatures - optimal temp above 45 degrees celsius Halophile - ANS the salt loving microbe - thrives in environments with high salt concentrations Antioxidants - ANS Their main role in the body is to quench free radicals that are released from oxygen and you get antioxidants from your diet Aerobe - ANS an organism that needs oxygen to grow and metabolize Obligate Aerobe: - ANS an organism that CANNOT grow or metabolize without oxygen Facultative aerobe - ANS does not require oxygen for its metabolism - but can metabolize if oxygen is present Microaerophile - ANS organisms that prefer lower concentrations of oxygen - doesn't need a lot of oxygen to metabolize Anaerobe - ANS doesn't possess the necessary enzymes to metabolize oxygen - meaning they metabolize without oxygen Obligate Anaerobe - ANS absolutely cannot tolerate the presence of oxygen - will DIE if oxygen is present Aerotolerant anaerobe - ANS don't use oxygen but have the mechanisms to break down oxygen if it is present - they don't use oxygen in their metabolism Lag Phase - ANS cells require a period of adjustment after being inoculated - the flat period on the graph where the populations appear not to be growing; the cells are not multiplying at their max rate; the population is sparse that sampling misses them Growth/Exponential Phase - ANS the population reaches its maximum growth rate - growth curve rate increases geometrically; phase lasts as long as cells have adequate nutrients/environment is favorable Stationary Phase - ANS rate of cell inhibition and cell death balances the rate of multiplication and population size remains constant - the population enters survival mode Death Phase - ANS population declines as death of cells exceeds the rate of multiplication - limiting factors intensify and cells die at an exponential rate When is the best time to treat someone with antibiotics? - ANS During the exponential phase because the cells are more vulnerable in this phase Metabolism - ANS All chemical reactions and physical workings of the cell - this includes building things up and breaking things down Catabolism - ANS breaking things down Anabolism - ANS building things up Biosynthesis - ANS taking smaller molecules and building them into larger molecules Enzymes - ANS Enzymes: made up of proteins and sometimes RNAs - they will speed up the chemical reactions that are neither used or destroyed in the chemical reaction (catalyst) What do enzymes do? - ANS lowers the activation energy - speeding up the reaction and making it easier to occur Cofactor - ANS A nonprotein metal molecule or ion that is required for the proper functioning of an enzyme. coenzyme - ANS an organic cofactor required for enzyme activity ex: vitamins Oxidoreductases - ANS catalyze oxidation-reduction reactions that involve the transfer of electrons Oxidation - ANS loss of electrons Reduction - ANS gain of electrons NAD and FAD - ANS are electron carriers (coenzyme carriers) constitutive enzymes - ANS always present, always produced in equal amounts or at equal rates, regardless of the amount of substrate Regulated enzymes - ANS not constantly present; production is turned on (induced) or turned off (repressed) in response to changes in the substrate concentration Competitive inhibition - ANS A molecule that resembles the substrate occupies the active site, preventing the substrate from binding Enzyme cannot act on the inhibitor and is effectively shut down enzymatic repression - ANS represses at the genetic (DNA) level to stop enzyme production, and therefore, activity Denaturation - ANS A process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or salt concentration or by high temperature. Also refers to the separation of the two strands of the DNA double helix, caused by similar factors. noncompetitive inhibitor - ANS A substance that reduces the activity of an enzyme without entering an active site. By binding elsewhere on the enzyme, a noncompetitive inhibitor changes the shape of the enzyme so that the active site no longer effectively catalyzes the conversion of substrate to product. NAD - ANS Most common electron carrier Carries hydrogens and electrons from dehydrogenation reactions aerobic metabolism - ANS The cellular process in which oxygen is used to metabolize glucose. Energy is produced in an efficient manner with minimal waste products. anaerobic metabolism - ANS The cellular process in which glucose is metabolized into energy without oxygen. Energy is produced in an inefficient manner with many waste products. ATP (adenosine triphosphate) - ANS Composed of a sugar ribose, nitrogenous base adenine, and a chain of three phosphate groups bonded to it. Metabolic role of ATP - ANS Primary energy currency of the cell. When it is used in a chemical reaction, it must be replaced ATP utilization and replenishment is an ongoing cycle aerobic respiration - ANS Series of reactions that converts glucose to CO2 and allows the cell to recover significant amounts of energy - requires oxygen anaerobic respiration - ANS Utilizes glycolysis and the Kreb's cycle and the respiratory chain but does not use oxygen as the final electron acceptor fermentation (anaerobic respiration) - ANS the breakdown of sugars without the use of oxygen, regenerate NAD+ so glycolysis can continue Glycolysis - ANS the breakdown of glucose by enzymes, releasing energy and pyruvic acid (2) Krebs Cycle (Citric Acid Cycle) - ANS The Krebs Cycle, also known as the citric acid cycle, takes place in the matrix of the mitochondria. In the Krebs Cycle, each of the two acetyl coenzyme A molecules enter the cycle and combine with oxaloacetate to form citric acid, which then loses two carbons as carbon dioxide. The cycle is now ready to begin again with the second Acetyl CoA. For each Acetyl CoA, the Krebs Cycle produces 1 ATP, 3 NADH, and 1 FADH2.