Unit 1 - Cell Biology Flashcards
what is diffusion?
diffusion is the movement of molecules down a concentration gradient from a region of high concentration to a region of low concentration
when does diffusion stop?
diffusion will continue until the concentrations are equal, therefore is it the gradient that drives the movement - no energy is required
what is osmosis?
osmosis is the movement of water down a concentration gradient from a region of high water concentration to a region of low water concentration across a selectively permeable membrane (it is a special example of diffusion)
why is diffusion important to cells?
diffusion is important to cells because it allows them to gain the useful substances they require to abstain energy and grow, and let’s them get rid of waste products
what colour is Benedict’s solution?
blue
what colour does Benedict’s solution turn in the presence of glucose?
brick red
what colour is iodine?
yellow/brown
what colour does iodine turn in the presence of starch?
blue/black
what are proteins composed of ?
proteins are composed of chains of amino acids
where are receptor proteins located?
receptor proteins are located in the cell membrane and recognise and bind to specific substances outside of the cell
what is the name of the substance that the enzyme acts upon?
the substrate
which 2 types of reactions can enzymes catalyse?
synthesis reactions (building up)
degradation reactions (breaking down)
what is phosphorylation?
phosphorylation is an enzyme controlled process by which a phosphate group is added to a molecule
what happens to an enzyme when the temperature is increased?
when a enzyme is heated, the shape of the active site changes which means the enzyme and substrate no longer fit together. The change is permanent and we can say that the enzyme has been denatured
what is respiration?
respiration is an enzyme controlled reaction
