Biology BY4

noahtattersall's version from 2015-06-06 10:01


Question Answer
ATPAdenosine triphosphate consisting of an organic base, adenine, a five-carbon sugar, ribose, and three phosphate groups linked together.
PhosphorylationThe addition of phosphate to ADP.
Oxidative phosphorylationOccurs on the membranes of mitochondria during aerobic respiration.
Substrate-level phosphorylationOccurs when phosphate groups are transferred from donor molecules to ADP to make ATP.
PhotophosphorylationOccurs on the membranes of the chloroplasts during photosynthesis.


Question Answer
Uses of ATPMetabolic processes, synthesis of DNA from nucleotides, Active Transport, Movement, muscle contraction, Nerve transmission, active transport of Na+ and K+ ions, Synthesis of materials within cell, Secretion – packaging and transport in vesicles
Aerobic respirationGlucose + oxygen → carbon dioxide + water + lots of ATP
Anaerobic respirationAbsence of oxygen. Produces little energy. Produces lactate in animals, ethanol and carbon dioxide in yeast
DehydrogenationRemoval of hydrogen
DecarboxylationRemoval of carbon dioxide


Question Answer
CoenzymeMolecule required by some enzymes in order to function e.g. NAD and FAD
Chemiosmotic theoryA model to explain the synthesis of ATP. The theory proposes that the energy for ATP synthesis originates from the electrochemical gradient of protons across a membrane.
ATP yield in aerobic respiration38 ATPs
ATP yield in anaerobic respiration2 ATPs
Lipids in respirationSplits into glycerol and fatty acids. Glycerol enters as triose phosphate, fatty acids as acetyl CoA.


Question Answer
Protein in respirationHydrolysed into amino acids and then deaminated in the liver. The amino group is converted into urea. The residue is converted into acetyl CoA, pyruvic acid or a Krebs cycle intermediate.
Primary pigmentsChlorophylls, Carotenoids.
Chlorophyllsabsorb light energy in the red and blue-violet regions of the spectrum.
Carotenoidsabsorb light energy in the blue-violet region of the spectrum.
Accessory pigmentsCarotenoids – carotenes and xanthophylls


Question Answer
PhotolysisSplitting of water molecules by light
Calvin cycleExperiments using carbon-14 (radioactive isotope) and the unicellular algae, Chlorella. Using lollipop vessel. Samples quenched using hot methanol.
Gram StainingA method of staining bacteria as an aid to their identification.
Gram positive Colourviolet
Gram negative Colourred/pink


Question Answer
Gram positivePhospholipid bilayer, Thick layer of peptidoglycan, More susceptible to penicillin and lysozyme.
Gram negativePhospholipid bilayer, Thin layer of peptidoglycan, Lipopolysaccharide layer, Less susceptible to penicillin and lysozyme
Conditions necessary for culturing bacteriaNutrients – carbon (glucose), nitrogen – inorganic (Nitrate, NO3-) and organic (Ammonia NH3), mineral salts in nutrient media, agar. Temperature, pH, Oxygen
Obligate aerobeRequires oxygen for metabolism
Obligate anaerobeCannot grow in the presence of oxygen


Question Answer
Facultative anaerobeGrows best in the presence of oxygen but can nevertheless survive in its absence.
AsepticA procedure performed under sterile conditions.
PathogenA disease causing micro-organism
Colony of bacteriaA cluster of cells which arise from a single bacterium by asexual reproduction.
FermenterVessel used to culture micro-organisms, usually on an industrial scale.


Question Answer
Total countsBoth living and dead cells
Viable countsLiving cells only
Number of colony forming unitsDilution factor x number of colonies
Secondary metaboliteA chemical which is not necessary for the growth of the fungus and is produced after the exponential phase of growth is completed, when glucose is depleted.
PopulationA group of organisms of a single species interbreeding and occupying a particular area.


Question Answer
Birth rateThe reproductive capacity of the population.
ImmigrationThe movement of individuals into a population.
Lag phasePreparation for growth with intense metabolic activity.
Exponential phaseCells divide at a constant rate with the population doubling per unit time. The cell population increases geometrically.
Stationary phaseWhen birth rate of new individuals is equal to the death rate of older ones.


Question Answer
Death phaseDeath rate if greater than birth rate.
Biotic factorsFactors which make up the living part of the environment of an organism, e.g. predation, parasitism, competition, disease
Abiotic factorsFactors which make up the non living parts of the environment of an organism, e.g. temperature, pH, light
Carrying capacityThe maximum population size that can be supported by the available resources.
Density dependent factorsTheir effect increases as the density of the population increases e.g. disease, depletion of food supply, accumulation of toxic waste


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Density independent factorsTheir effect doesn’t depend on the population density, e.g. freezing, flood, fire
Intraspecific competitionCompetition between individuals of the same species.
Interspecific competitionCompetition between individuals of different species.
NicheThe ecological role and space that an organism fills in an ecosystem.
PestAny organism that competes with or adversely affects a population of organisms that is of economic importance.


Question Answer
PesticidesPoisonous chemicals used to control organisms considered harmful to agriculture or organisms involved in disease transmission.
ResistanceThe ability of an organism to survive exposure to a dose of poison which would normally be lethal to it.
Biological controlThe controls of a pest by using organisms that are either predators or parasites of the pest organism.
Negative feedbackWhen there is a change in a monitored variable a response is triggered to counteract the initial fluctuation.
Saprobiont (saphrophyte)A micro-organism that obtains its food from the dead or decaying remains of other organisms.


Question Answer
Integrated pest controlThe combining of various methods to control pests.
DeaminationThe breakdown of excess amino acids in the liver, by the removal of the amine group. Urea produced
OsmoregulationThe homeostatic control of body water.
Metabolic waterWater produced from the oxidation of food reserves.
Reflux arcThe pathway along which impulses are carried from a receptor to an effector, without involving the brain. Stimulus, receptor, sensory neurone, relay neurone, motor neurone, effector, response


Question Answer
Resting potentialThe potential difference between the inside and the outside of a membrane when a nerve impulse is not being conducted.
Action potentialA change that occurs in the electrical charge across the membrane of an axon when it is stimulated and a nerve impulse passes.
DepolarisationA temporary reversal of charge on the membrane of a neurone that takes place when a nerve impulse is transmitted.
Saltatory conductionTransmission of a nerve impulse along a myelinated axon in which the action potential jumps from one node of Ranvier to another.
Excitory drugsStimulate the nervous system by creating more action potentials.


Question Answer
Inhibitory drugsInhibit the nervous system by creating fewer action potentials.
Neuromuscular junctionA synapse that occurs between a neurone and a muscle.
PhotoperiodismThe term used to describe the influence of relative periods of light and darkness on flowering.
PhytochromeThe photoreceptor responsible for absorbing light.