All Flashcards
Acid
A sour substance that can attack metal, clothing or our skin. The chemical opposite of an alkali. When dissolved in water, it’s solution had a ph number of less than 7. Acids are proton H+ ion) donors
Activation energy
The minimum energy needed to start off a reaction
Active site
The site on an enzyme where reactants bind
Algal cells
The cells of algae, single-called or simple multi- cellular organisms, which can photosynthesis but are not plants.
Alkali
It’s a solution which had a ph number of more than 7
Allele
A version of a particular gene
Alpha radiation
Alpha particles, each composed of two neutrons, emitted by an unstable nuclei
Alternating current
Electric current in a circuit which repeatedly reverses it’s direction
Amino acid
The building block of protein
Amylase
The enzyme made in the salivary glands and the pancreas that speeds up the break down of starch and simple sugars
Anhydrous
Describes a substance which does not contain water
Aqueous solution
The mixture made by adding a soluble substance to water
Atomic number
The number of proteins (which equals the number of electrons) in an atom. It is sometimes called the proton number.
Attract
To cause to move nearer
Acceleration
Change in velocity per second (In metres per second per second, m/s2 )
Bacterial colony
A population of billions of bacteria grown in a culture
Base
The oxide, hydroxide or carbonate of a metal that will react with an acid, forming a salt as one of the products. (If a base dissolves in water it is called an alkali). Bases are proton (H+ ion) acceptors
Beta radiation
Beta particles that are high-energy electrons created in and emitted from unstable nuclei
Bile
Yellowy-green liquid made in the liver and stored in the gall bladder. It is released into he small intestine and emulsifies fats
Biological detergent
Washing detergent that contains enzymes
Biomass
Biological material from a living thing or recently living organisms.
Black dwarf
A star that has faded out and gone cold.
Black hole
An object in space that has so much mass that nothing, not even light, can escape from its gravitational field
Braking distance
The distance traveled by a vehicle during the time it’s brakes act
Cable
Two or three insulated wires surrounded by an outer layer of rubber or flexible plastic h
Carbohydrase
Enzyme that speeds up the chemical breakdown of carbohydrates
Carrier
Individual who is heterozygous for a faulty allele that causes a genetic disease
Catalyst
A substance that speeds up a chemical reaction. At the end of the reaction the catalyst ends up unchanged
Cell membrane
The membrane around the contents of a cell that controls what moves in and out of the cell
Cell wall
A rigid structure that surrounds the cells of living organisms apart from animals
Cellulose
A big carbohydrate molecule that makes up plant and algal cell walls
Chain reaction
Reactions in which one reaction causes further reactions, ect. A nuclear chain reaction occurs when fission neutrons cause further fission, so more fission neutrons are released. These go on top to produce further fission.
Chlorophyll
The green pigment contained in chloroplasts
Chloroplast
The organelle in which photosynthesis takes place
Chromatography
The pro see whereby small amounts of dissolves substances are separated by running a solvent along a material such as absorbent paper
Circuit breaker
An electromagnetic switch which opens and cuts the current off if too much current passes through it.
Collision theory
An explanation of chemical reactions in terms of reacting partials colliding with sufficient energy for a reaction to take place.
Concentration gradient
The gradient between an area where a substance is at a high concentration and an area at a low concentration
Conservation of momentum
In a closed system, the total momentum before an event is equal to the total momentum after the event. Momentum is conserved in any Collin or explosion provided no external forces act on the objects that collide or explode
Covalent bonding
The attraction between two atoms that share one or more pairs of electrons
Crumple zone
Region of a vehicle designed to crumple I’m a collision to reduce the force on occupants
Cystic fibrosis
A genetic disease that affects the lungs, digestive and reproductive systems. It is inherited through a recessive allele
Cytoplasm
The water-bases gel in which organelles of all living cells are suspended
Deceleration
Change of velocity per second when an object slows down
Delocalises electron
Bonding electron that is no longer associated with any one particular atom
Denatured
Change the shape of an enzyme so that it can no longer speed up a reaction
Differentiate
Specialise for a particular function
Diffusion
The net movement of particles of a gas or a solute from an area of high concentration to an area of low concentration (along a concentration gradient)
Digestion
Breaking down small molecules by the digestive enzymes.
Digestive juice
The mixture of enzymes and other chemicals produced by the digestive system
Digestive system
The organ system running from the mouth to the anus where food is digested
Diode
Electrical device that allows current flow in one direction only
Direct Current
Electric current in a circuit that is in one direction only
Directly proportional
A graph will show this if the line of best fit is a straight line through the origin
DNA fingerprint
Pattern produced by analysing the DNA which can be used to identify an individual
Dominant
The characteristic that will show up in the offspring even if only one of the alleles is inherited
Dot and Cross diagram
A drawing to show the arrangement of the outer shell electrons only of the atoms or ions in a substance
Drag force
A force opposing the motion of an object due to fluid (eg. Air) flowing past the object as it moves
Elastic
A material is elastic if it is able to regain its shape after it has been squashed or stretched
Elastic potential energy
Energy stored in an elastic object when work is done to change its shape
Electrolyte
A liquid, containing free-moving ions, that is broken down by electricity in the process of electrolysis
Electron
A tiny particle with a negative charge. Electrons orbit the nucleus in atoms or ions
Empirical formula
The simplest ratio of elements in a compound
Endothermic
A reaction that takes in energy from the surroundings
Enzyme
A protein molecule that acts as a biological catalyst
Epidermal tissue
The tissue of the epidermis - the outer layer of an organism
Epithelial tissue
Tissue made up of relatively unspecialised cells that line the tubes and organs of the body
Exothermic
A reaction that gives out energy to the surroundings
Extinction
Extinction is the permanent loss of all members of a species
Fatty acid
Building block of lipids
Filament bulb
Electrical device designed to produce light
Force
A force can change the motion of an object (in Newtons, N)
Frequency (of an alternating current)
The number of complete cycles an alternating current passes through each second. The unit of frequency is the hertz (Hz)
Friction
Force opposing the movement of one surface over another
Fructose syrup
A sugar syrup
Fullerene
Form of the element carbon that can form a large cage-like structure, based on hexagonal rings of carbon atoms
Fuse
A fuse contains a thin wire that melts and cuts the current off it too much current passes through it
Gamma radiation
Electromagnetic radiation emitted from unstable nuclei in radioactive substances
Gas chromatography
The process of separating the components in a mixture by passing the vapours through a column and detecting them as they leave the column at different times
Genetic disorder
Disease that is inherited
Genetic material
The DNA that carries the instructions for making a new cell or a new individual
Geographical isolation
This is when two populations become physically isolated by a geographical feature
Giant covalent structure
A huge 3-D network of covalently bonded atoms (eg. the giant lattice of carbon atoms in diamond or graphite)
Giant lattice
A huge 3-D network of atoms or ions (eg. The giant ionic lattice in sodium chloride)
Giant structure
See giant lattice
Glandular tissue
The tissue that makes up the glands and secretes chemicals, eg. Enzymes, hormones
Glucose
A simple sugar
Glycerol
Building block of lipids
Glycogen
Carbohydrate store in animals, including the muscles, liver and brain of the human body
Gradient
Change of the quality plotted on the y-axis divided by the change of the quality plotted on the x-axis
Gravitational attraction
Force that pulls two masses together
Gravitational field strength
The force of gravity on an object of mass 1Kg (in Newtons per kilogram , N/kg
Gravitational potential energy
Energy of an object due to its position in s gravitational field. Near the Earth’s surface, change of GPE (in joules, J) = weight (in newtons, N) X vertical distance moved (in metres, m)
Half-life (of a radioactive isotope)
Average time taken for the number of nuclei of the isotope (or mass of the isotope) in a sample to halve
Hooke’s law
The extension of a spring is directly proportional to the force applied, provided it’s limit proportionality is not exceeded
Hydrated
Describes a substance that contains water in its crystals, eg hydrated copper sulphate
Impact time
Time taken for a collision to take place
Inert
Unreactive
Insoluble molecules
Molecules that will not dissolve in a particular solvent such as water
Insulating
Reducing energy transfer by heating
Intermolecular force
The attraction between the individual molecules in a covalently bonded substance
Ion
A charged particle produced by the loss of gain of electrons
Ionic bonding
The electrostatic force of attraction between positively and negatively charged ions
Ionisation
Any process in which atoms become charged
Isomerase
An enzyme that converts one form of a molecule into another
Isotope
Atom that has the same number of protons but different number of neutron, ie. It has the same atomic number but different mass number
Kinetic energy
Energy of a moving object due to its motion; kinetic energy (in joules, J) = mass (in kilograms, kg) X speed (in m2/s2)
Lactic acid
One product of anaerobic respiration. It builds up in the muscles with exercise. Important in yoghurt-and cheese-making processes
Light energy
Energy in the form of light
Light dependent resistor
Device with a resistance that varies with the amount of light falling on it
Limit of proportionality
The limit for Hooke’s law applied to the extension of a stretched Spring
Limiting factor
Factor that limits the rate of a reaction eg. Temperature, pH, light levels (photosynthesis)
Lipase
Enzyme that breaks down fats and oils into fatty acids and glycerol
Lipid
Oil or fat
Live wire
The wire of a mains circuit that had a potential that alternates from positive to negative and back each cycle
Drag force
A force opposing the motion of an object due to fluid (eg. Air) flowing past the object as it moves
Elastic
A material is elastic if it is able to regain its shape after it has been squashed or stretched
Elastic potential energy
Energy stored in an elastic object when work is done to change its shape
Electrolyte
A liquid, containing free-moving ions, that is broken down by electricity in the process of electrolysis
Electron
A tiny particle with a negative charge. Electrons orbit the nucleus in atoms or ions
Empirical formula
The simplest ratio of elements in a compound
Endothermic
A reaction that takes in energy from the surroundings
Enzyme
A protein molecule that acts as a biological catalyst
Epidermal tissue
The tissue of the epidermis - the outer layer of an organism
Epithelial tissue
Tissue made up of relatively unspecialised cells that line the tubes and organs of the body
Exothermic
A reaction that gives out energy to the surroundings
Extinction
Extinction is the permanent loss of all members of a species
Fatty acid
Building block of lipids
Filament bulb
Electrical device designed to produce light
Force
A force can change the motion of an object (in Newtons, N)
Frequency (of an alternating current)
The number of complete cycles an alternating current passes through each second. The unit of frequency is the hertz (Hz)
Friction
Force opposing the movement of one surface over another
Fructose syrup
A sugar syrup
Fullerene
Form of the element carbon that can form a large cage-like structure, based on hexagonal rings of carbon atoms
Fuse
A fuse contains a thin wire that melts and cuts the current off it too much current passes through it
Gamma radiation
Electromagnetic radiation emitted from unstable nuclei in radioactive substances
Gas chromatography
The process of separating the components in a mixture by passing the vapours through a column and detecting them as they leave the column at different times
Genetic disorder
Disease that is inherited
Genetic material
The DNA that carries the instructions for making a new cell or a new individual
Geographical isolation
This is when two populations become physically isolated by a geographical feature
Giant covalent structure
A huge 3-D network of covalently bonded atoms (eg. the giant lattice of carbon atoms in diamond or graphite)
Giant lattice
A huge 3-D network of atoms or ions (eg. The giant ionic lattice in sodium chloride)
Giant structure
See giant lattice
Glandular tissue
The tissue that makes up the glands and secretes chemicals, eg. Enzymes, hormones
Glucose
A simple sugar
Glycerol
Building block of lipids
Glycogen
Carbohydrate store in animals, including the muscles, liver and brain of the human body
Gradient
Change of the quality plotted on the y-axis divided by the change of the quality plotted on the x-axis
Gravitational attraction
Force that pulls two masses together
Gravitational field strength
The force of gravity on an object of mass 1Kg (in Newtons per kilogram , N/kg
Gravitational potential energy
Energy of an object due to its position in s gravitational field. Near the Earth’s surface, change of GPE (in joules, J) = weight (in newtons, N) X vertical distance moved (in metres, m)
Half-life (of a radioactive isotope)
Average time taken for the number of nuclei of the isotope (or mass of the isotope) in a sample to halve
Hooke’s law
The extension of a spring is directly proportional to the force applied, provided it’s limit proportionality is not exceeded
Hydrated
Describes a substance that contains water in its crystals, eg hydrated copper sulphate
Impact time
Time taken for a collision to take place
Inert
Unreactive
Insoluble molecules
Molecules that will not dissolve in a particular solvent such as water
Insulating
Reducing energy transfer by heating
Intermolecular force
The attraction between the individual molecules in a covalently bonded substance
Ion
A charged particle produced by the loss of gain of electrons
Ionic bonding
The electrostatic force of attraction between positively and negatively charged ions
Ionisation
Any process in which atoms become charged
Isomerase
An enzyme that converts one form of a molecule into another
Isotope
Atom that has the same number of protons but different number of neutron, ie. It has the same atomic number but different mass number
Kinetic energy
Energy of a moving object due to its motion; kinetic energy (in joules, J) = mass (in kilograms, kg) X speed (in m2/s2)
Lactic acid
One product of anaerobic respiration. It builds up in the muscles with exercise. Important in yoghurt-and cheese-making processes
Light energy
Energy in the form of light
Light dependent resistor
Device with a resistance that varies with the amount of light falling on it
Limit of proportionality
The limit for Hooke’s law applied to the extension of a stretched Spring
Limiting factor
Factor that limits the rate of a reaction eg. Temperature, pH, light levels (photosynthesis)
Lipase
Enzyme that breaks down fats and oils into fatty acids and glycerol
Lipid
Oil or fat
Live wire
The wire of a mains circuit that had a potential that alternates from positive to negative and back each cycle
