Contains GENETIC material which CONTROLS the ACTIVITIES of the CELL
Most CHEMICAL processes take place here and are controlled by ENZYMES
CONTROLS the MOVEMENT of SUBSRANCES iN and OUT of the CELL
Most energy is released by RESPIRATION here
Protein synthesis happens here
Strengthenes the cell
Contains CHLOROPHYLL which ABSORBS LIGHT energy for PHOTOSYNTHESIS
FILLED with CELL SAP that is used to HELP keel the CELL TURGID
ABSORBS LIGHT for PHOTOSYNTHESIS.
Packed with CHLOROPLASTS
CLOSELY PACKED CELLS form a contiuous layer for EFFICIENT ABSORPTION of SUNLIGHT.
Root hair cell
ABSORBS WATER and MINERALS IONS from SOIL.
Very THIN WALLS which gives a LARGE SURFACE AREA.
FERTILISES FEMALE GAMETE.
HEAD contains GENETIC info and ENZYME to help penetrate EGG MEMBRANE.
Middle section filled with MITOCHONDRIA for ENERGY.
TAIL helps the sperm move to the egg.
Red blood cells
Contain HAEMOGLOBIN to carry oxygen around to the cells.
THIN OUTER MEMBRANE to let OXYGEN DIFFUSE.
Shape increases SURFACE AREA to allow more OXYGEN to be ABSORBED.
NO NUCLEUS, WHOLE CELL FULL OF HAEMOGLOBIN.
Dissolved substances have to pass theough a cell membrane in order to get in or out.
Diffusion occurs when particles SPREAD. Move from a region of HIGH CONCENTRATION to a region of LOW CONCENTRATION. Happens when particles are free to move around.
Particles diffuse down a CONCENTRATION GRADIENT from an area of HIGH CONCENTRATION to and area of LOW CONCENTRATION.
Water can move across a cell membrane because of osmosis. For it to happen you need@
Two solutions/ different concentrations
A PARTIALLY PERMEABLE MEMBRANE to separate them (partially permeable membrane only allows some substances to pass through.
Moves from a LESS CONCENTRATED SOLUTION to a more CONCENTRATED SOLUTION through a PARTIALLY PERMEBALE MEMBRANE.
Level on the more concentrated side of the membrane rises whereas the one with the less concentration decrases. When the concentration is the same on both sides of the membrane the movement of water molecules will be the same in both directions.
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.
Some molecules leave the cell by diffusion;
- carbon dioxide
Some molecules enter;
This is allowed by the cell membrane which is SEMI-PERMEABLE
Not all molecules can pass through eg
Osmosis is a special type of diffusion of water molecules.
Osmosis is the movement od water molecules from an area of high concentration water molecules to an area of low concentration water molecules through a semi-permeable membrane.