Definitions Flashcards
Immobilised enzyme
An enzyme that is attached or fixed to another enzyme or an inert material.
Bioprocessing
The use of enzyme-controlled reactions to produce a product
Bioreactor
A vessel in which biological reactions take place
Denatured enzyme
A denatured enzyme is an enzyme that has lost its shape and can no longer function
Selectively permeable membrane
Allows only certain molecules to pass through it
Diffusion
The spreading out of molecules from an area of high concentration to an area of low concentration
Osmosis
The movement of water across a semi-permeable membrane from an area of high water concentration to an area of low water concentration
Active site
The part of an enzyme that combines with the substrate
Turgor
The outward pressure of the cytoplasm and the vacuole against the cell wall
Plasmolysis
The loss of water from the cytoplasm and the movement of the cell membrane from the cell wall
Cell continuity
All cells develop from pre-existing cells
Chromosomes
Chromosomes are coiled threads of DNA (which forms genes) and protein. Role: They carry genes.
Gene
A section of DNA that contains the instructions for the formation of a protein
Haploid cell
A haploid cell has one set of chromosomes (n)
Diploid cell
A diploid cell had two sets of chromosomes (2n)
Homologous pair
A pair of two chromosomes of similar size with the same sequence of genes
Cell Cycle
The cell cycle describes the changes that take place in a cell during the period between one cell division and the next
Interphase
The phase in the cell cycle when the cell is not dividing. It is the longest phase in the cell.
Mitosis
A form of nuclear division in which one nucleus divides to form two nuclei, each containing the same number of chromosomes with identical genes
Cancer
Cancer occurs when cells lose the ability to control the rate of mitosis and the number of times mitosis takes place
Tumour
A tumour results when a cell (or group of cells) lose the ability to control the rate of mitosis
Metastasis
The movement of malignant cells
Meiosis
Meiosis is a form of nuclear division in which the four daughter nuclei contain half the chromosome number of the parent nucleus
Diploid number
The total number of chromosomes in a cell
Autotropism
An organism makes its own food
Photosynthetic organism
Uses light to make food
Chemosynthetic organism
Uses energy from chemical reactions to make food
Heterotropism
An organism takes in food made by other organisms
Saprophytic organism
Takes in food from dead organic matter
They allow for mineral recycling
Parasites
Organisms that take in food from a live host and usually cause harm
Pathogen
A disease-causing micro-organism
Antibiotics
Antibiotics are chemicals produced by micro-organisms that stop the growth of, or kill, other micro-organisms, without damaging human tissue
Single Cell Protein Production
The use of bacteria, yeasts, fungi and algae to produce edible forms of protein
Batch Culture
The growth of cells in a bioreactor over a short period of time and under ideal conditions until all the nutrients are used up
Continuous flow food processing
The growth of cells in a bioreactor, where nutrients are added and the end products are removed all the time at a rate that maintains the volume of liquid and the number of cells
Asepsis
Measures are taken to exclude unwanted micro-organisms
Sterile
All micro-organisms are destroyed
Venation
The pattern of veins in a leaf
Lignin
A strengthening material found in some plant cell walls
Transpiration
The loss (by evaporation) of water vapour from the leaves and other aerial parts of a plant
Cohesion
The sticking of similar molecules to each other
Adhesion
Adhesion occurs when different molecules stick together
Nutrient Medium
A nutrient medium is a material containing food used to grow micro-organisms
Phagocytosis
The way in which a cell ‘eats’ solid particles
Leukaemia
A form of cancer in which white blood cells are produced too rapidly and are immature
Anaemia
A condition where there is a lack of haemoglobin in the blood, causing a loss of energy and pale skin colour
Open circulatory system
Blood leaves blood vessels and flows around the cells of the animal’s body before re-entering blood vessels again
e.g. Crab
Closed circulatory system
Blood remains in a continuous system of blood vessels
Blood pressure
The force the blood exerts against the wall of a blood vessel
Portal system
A portal system is a blood patheay that begins and ends in capillaries
Pulse
The alternate expansion and contraction of the arteries.
The average pulse is 72 beats her minute.
Digestion
Digestion is the physical and chemical breakdown of food to obtain the nutrients from food.
Peristalsis
Peristalsis is a wave of muscular action in the walls of the alimentary canal that moves the contents along
Balanced Diet
A balanced diet is a diet that contains all the necessary food types in the correct proportions for the needs of the body
Mechanical Digestion
Takes place in the mouth by the chewing and grinding action of teeth on food
Chemical digestion
The breakdown of food using enzymes
Ingestion
The taking of food into the digestive system
Absorption
Occurs when the digested food passes from the digestive system and enters into the blood
Egestion
The removal of unabsorbed waste from the digestive system
Physical digestion
The mechanical breakdown of food
A vestigal organ
A vestigal organ has lost its former use
Definition of pharynx
The pharynx is the throat
Larynx
The voice box
Excretion
Excretion is the removal of metabolic waste from the body
Homeostasis
The maintenance of a constant internal environment in an organism
Ectotherm
An ectotherm gains or loses heat from or to its external environment e.g. lizard
Endotherm
An endotherm generates its own heat from metabolic reactions e.g. human
Piloerection
This is when erector muscles contract, causing the hairs to stand up on the skin (goose bumps).
A layer of warm air is trapped close to the skin by the hairs, helping to reduce heat loss from the body.
Vasoconstriction
Blood vessels in the skin contract when we are cold, reducing heat loss.
Filtration (kidneys)
Filtration means that water and small molecules pass (under high pressure) from the blood into the nephron
Reabsorption (kidneys)
Reabsorption means that molecules pass from the nephron back into the blood
Active transport
Active transport means that energy (ATP) is used to move molecules, often from low concentrations to high concentrations
Glomerular filtrate
Glomerular filtrate is a dilute solution of glucose, amino acids, urea, salts and water that have been forced out of the plasma
Secretion
Secretion means that some substances pass from the blood into the nephron
Symbiosis
Symbiosis occurs when two organisms of different species live in close association and at least one of them benefits
Mutualism
A form of symbiosis where both organisms benefit from the association
Trophic level
A trophic level is a feeding stage in a food chain
Competition
Competition occurs when organisms actively struggle for a resource that is in short supply
Intra-specific competition
Intra-specific competition takes place between members of the same species
Inter-specific competition
Inter-specific competition takes place between members of different species
Pyramid of Numbers
A pyramid of numbers represents the number of organisms at each trophic level in a food chain
Contest competition
In contest competition, there is an active physical contest between two individual organisms
Scramble competition
In scramble competition, all of the competing individuals get some of the resource
Predation
Predation is the catching, killing and eating of another organism
Predator
A predator is an organism that catches, kills and eats another organism
Prey
The prey is the organism that is eaten by the predator
Parasitism
Parasitism occurs when two organisms of different species live in close association where one organism benefits but the other is harmed
Exoparasites
Live on the outside of the host
Endoparasites
Live inside the host
Ecology
The study of the interactions between living things and their environment
Biosphere
The part of the earth inhabited by living organisms
Ecosystem
An ecosystem is a group of clearly distinguished organisms that interact with their environment as a unit
Population
All the members of the same species in an area
Community
All the different populations in an area
Habitat
The place where an organism lives
Abiotic factors
Non-living factors
Biotic factors
Living factors
Edaphic factors
Factors that relate to soil
Climatic factors
Factors that refer to weather over a long period of time
Food chain
A food chain is a sequence of organisms in which each one is eaten by the next member in the chain
Decomposers
Organisms that feed on dead organic matter
Fauna
All the animals in an ecosystem
Flora
All the plants in an ecosystem
Producers
Organisms that carry out photosynthesis
Detritus feeders
Organisms that feed on small pieces of dead organic matter
Food web
A food web consists of two or more interlinked food chains
Niche of an organism
The niche of an organism is the role it plays in the community
Nutrient recycling
The way in which elements are exchanged between living and non-living components of an ecosystem
Nitrogen fixation
The conversion of nitrogen gas into ammonia, ammonium or nitrate
Nitrification
The conversion of ammonia and ammonium compounds to nitrite and then to nitrate
Denitrification
The conversion of nitrates to nitrogen gas
Pollution
Pollution is any harmful addition to the environment
Pollutant
A pollutant is a harmful addition to the environment
Conservation
Conservation is the wise management of the existing natural resources in an ecosystem, in order to maintain a wide range of habitats and prevent the death and extinction of organisms
Eutrophication
The addition of nutrients to fresh water. This leads to a lack of oxygen in the water.
