BIOLOGY CELL BIOLOGY KEY TERMS AND DEFINITIONS 2023 LATEST UPDATE.

Sub-cellular structures structures found in cells that include the nucleus, mitochondria, chloroplasts and ribosomes Nucleus the control centre of the cell Cytoplasm the substance found in living cells (outside the nucleus), where chemical reactions take place Cell membrane a layer that holds the cytoplasm in a cell and controls what enters and leaves the cell Mitochondria the structures in the cytoplasm where energy is produced from chemical reactions Ribosomes small structures found in the cytoplasm of living cells where protein synthesis takes place Cell wall a protective layer, found outside the cell membrane of plant, fungal and bacterial cells, that helps to support the cell Cellulose a carbohydrate that makes up the cell wall of plants Vacuole a fluid-filled cavity in a cell that is used for storage and support Chloroplast a sub-cellular structure containing chlorophyll, which is found in plants and algae that carry out photosynthesis Prokaryotic organisms, such as bacteria, that do not have a nucleus or organelles such as mitochondria Eukaryotic cells that have a nucleus and sub-cellular organelles such as mitochondria Plasmid a small circle of bacterial DNA that is independent of the main bacterial chromosome Resolution the smallest distance apart two objects can be and still be seen as separate objects Electron microscope a device that fires electrons at a specimen to obtain a high resolution image Magnification how many times larger an image is than the real object Binary fission the process that enables a cell to split into two equal-sized, identical cells Agar a jelly made from algae that is used to culture microorganisms Culture a substance that provides the nutrients for the artificial growth of bacteria and other cells Petri dish a round, shallow dish used to grow bacteria Chromosomes long molecules found in the nucleus of all cells; made from DNA DNA nucleic acid molecules that contain genetic information and make up chromosomes Cell cycle the series of growth and division events that a cell goes through during its life Mitosis cell division that forms two daughter cells, each with the same number of chromosomes as the parent cell Undifferentiated a cell that has not yet become specialised Stem cell a human embryo cell or adult bone marrow cell that has yet to differentiate Embryonic stem cells cells found in an embryo that can differentiate into any type of cell Adult stem cells cells that can differentiate into limited types of cells Therapeutic cloning clones that are produced to treat diseases and will not be allowed to develop into new offspring Meristems areas of cells in plants that can divide to form new cells Diffusion the natural movement of particles from an area of high concentration to an area of low concentration Concentration gradient a change in the concentration of a substance from one region to another Surface area to volume ratio a way of comparing the surface area of an organism to its volume – the smaller this ratio, the harder it is to exchange substances with the environment at a fast enough rate Osmosis the movement of water, through a partially permeable membrane, into a solution with a lower water concentration Active transport the movement of substances against a