Topic 5- Glossary Flashcards
Biosphere
The part of the earth and its atmosphere which is inhabited by living organisms
Ecosystem
A relatively self-contained, interacting community of organisms
Abiotic
Physical and chemical aspects of an ecosystem
Biotic
Factors determined by organisms- predation and competition
Habitat
The place where the organisms live; the non-living part of an ecosystem;
Microhabitat
Area of distinct conditions within a habitat- e.g underside of a stone in a pond
Population
A group of individuals of the same species living in a particular habitat
Community
The living part of an ecosystem; all the plants and animals that live in a habitat i.e. all the populations
Species
A group of actually or potentially interbreeding natural populations that produce fertile offspring and that is reproductively isolated from other such groups.
Niche
The functional position of an organism in its environment, comprising its habitat and the resources it obtains there, and the periods of time it is active
Biodiversity
The variability among living organisms from all sources; it includes diversity within species, between species and within and between ecosystems
Competition
Intraspecific competition
Interspecific competition
Use of the same resource by two or more species, when the resource is present in insufficient supply for the combined needs of the species.
May be within members of same species ……………………………..
or between members of different species…………………………..
Edaphic factors
Factors connected with the soil structure, texture, pH, mineral content
Mutualism
Relationships in which both partners benefit
Biotic factors show effects related to the size of a population, and so are said to be __________ ________
Density-dependent
Topography
Physical factors of the environment including altitude, slope, aspect, and drainage.
Anthropogenic factors
Factors arising from human activity- biotic or abiotic
Zonation
A change in species composition through a habitat due to a change in environmental factor(s). The ecosystem will be divided into distinct zones, where each zone experiences similar abiotic/biotic conditions. This is particularly clear on a rocky shore. Here the fine balance between tolerance to desiccation and competitive ability is a major cause of the patterns seen.
Sites of Specific Scientific Interest SSIs
*Areas managed and protected to conserve specific rare or endangered species or habitats
Succession
The way in which the different species of organisms that make up a community change over a period of time. Can be seen clearly in sand dune systems.
Pioneer species
An organism that can survive extreme conditions (e.g. low nutrients, low water availability) or the first organism to colonise a newly formed habitat or a habitat that has been cleared of vegetation. Colonisation by these species will start to change the conditions of the habitat making it more suitable for other organisms to colonise.
Climax community
The stable community that make up the final stage of ecological succession. The nature of the climax community will depend on ecological conditions such as the climate.
Primary succession
Succession from an area which has not previously sustained a community, such as bare rock.
Secondary succession
Succession where an previous community has been cleared, e.g. land cleared for building or cleared by fire
Deflected succession
A stable pre-climax community which is maintained only by human activity, e.g. grazing results in this.
Phytoplankton
Algal plankton. Plankton refers to algae and animals kept in suspension by water turbulence. Phyto is a general botanical prefix.
Autotrophs
Organisms that can make their own organic compounds from inorganic compounds
Photosynthesis
The metabolic process by which light energy is trapped and used to fix carbon dioxide into compounds such as glucose.
Chemosynthetic autotrophs
Organisms that can produce organic compounds using energy released from chemical reactions.
OILRIG
Acronym to remember oxidation is loss of, reduction is gain, in electrons.
Photolysis
Splitting water into hydrogen ions, electrons and oxygen molecules, using light energy
Light dependent reaction
The process by which ATP and reduced NADP are generated in photosynthesis using energy from light and hydrogen from photolysis of water. The waste product of this reaction is oxygen.
Light independent reaction
The reactions where the products of the light dependent reaction are used to reduce carbon dioxide to form carbohydrate
Palisade mesophyll
The tall thin cells found near the upper surface of a leaf. They contain many chloroplasts and are an important site of photosynthesis.
Chloroplast
An organelle, bounded by a double membrane, containing a large surface area of membranes with pigments, enzymes and electron carriers required for photosynthesis
Thylakoid membrane
Interconnected, fluid-filled sacs within chloroplasts. Pigments and electron carriers are embedded in the membrane.
Stroma
Fluid surrounding the thylakoid membranes containing enzymes for the light independent reaction.
Granum (plural grana)
A stack of thylakoid membranes, joined together.
Inner chloroplast membrane
The second membrane of a chloroplast containing membrane-bound transport proteins. Regulates the passage of substances in and out of the chloroplast
Outer chloroplast membrane
Surrounds a chloroplast. Freely permeable to oxygen, water and carbon dioxide
Electron transport chain
A series of closely situated electron carrier molecules embedded in the thylakoid membrane
Photophosphorylation
The part of the light-dependent reaction of photosynthesis in which energy released in the electron transfer chain is used to produce ATP. The electrons being transferred were lost from the chlorophyll molecule, when chlorophyll absorbs light energy. Light is the initial energy source for ATP production.
Photosystem I and II
Photosynthetic pigments arranged in clusters in the thylakoid membrane, where several hundred pigment molecules surround a primary chlorophyll molecule. These acts as a sort of light funnel, absorbing light and passing the energy from molecule to molecule until it reaches the primary chlorophyll molecule at the reaction centre.
ATP
The most important energy transfer molecule within cells. Composed of adenine, joined to ribose that is also joined to three phosphate groups. When formed, useful energy is stored; when broken down (third phosphate group lost), energy is released to drive other energy requiring (endergonic) reactions.
Coenzyme
An organic substance which plays an essential part in an enzyme catalysed reaction, but which are only involved temporarily with the enzyme (cf. prosthetic group)
NADP
The coenzyme acting as a hydrogen carrier in photosynthesis.
Calvin cycle
The cyclic part of the light independent reaction of photosynthesis. It consists of a series of reactions in which carbon dioxide is reduced to glyceraldehyde 3-phosphate (GALP), while the carbon dioxide acceptor ribulose bisphosphate is regenerated. For every six molecules of carbon dioxide that enter the cycle, a net gain of two molecules of GALP result.
RuBISCO - ribulose bisphosphate carboxylase
The most common enzyme on the planet. It catalyses the fixation of carbon dioxide in the Calvin cycle
RuBP, Ribulose bisphosphate.
The five carbon compound which combines with carbon dioxide in the Calvin cycle.
Glycerate 3-phosphate (GP)
The first stable 3-carbon molecules produced in the light independent reaction
Glyceraldehyde 3-phosphate (GALP)
3-carbon molecules that combine to form glucose and other carbohydrates in the light independent reaction
Heterotrophs/ consumers
Organisms that take in large organic molecules produced by another species.
Trophic level
Level in a food chain occupied by a particular group of organisms
Omnivore
An organism that feeds on both plants and animals, therefore feeding at more than one trophic level in a food web.
Detritivores
Primary consumers that feed on dead organic matter e.g. wood lice, earthworms. They ingest the material and digest internally.
Decomposers
Species of bacteria and fungi that break down dead organisms and excreted materials. They secrete enzymes and digest externally, before absorbing the small soluble products of digestion.
