biology test 1

• The nucleus is the control center of the cell.
• osmosis: a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.
• active transport is the movement of molecules from a low concentration to a high concentration across a cell membrane against a concentration gradient
• diffusion: Diffusion is when particles or molecules move from an area of high concentration to an area of low concentration.
• how enzymes work: the active site is complementary to the substrate, the enzyme and substrate fit together
• denatured enzyme is an enzyme that has lost its active site and is no longer able to catalyze a reaction
• cell membrane is a selectively permeable barrier that controls the movement of substances in and out of the cell
• cell wall is made of cellulose and is found in plant cells
• cytoplasm: the material or protoplasm within a living cell, excluding the nucleus. has dna
• nucleus: the central and most important part of an object, movement, or group, forming the basis for its activity and growth, and controls the activities of the cell
• vacuole: a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid.
• chloroplast: a plastid in green plant cells which contains chlorophyll and in which photosynthesis takes place.