Biology-Term 1 '24 P1

• Organelles: Small structures within a cell that perform specific functions.
• Tissue: A group of cells that work together to carry out a common function.
• Organ: Different tissues that work together to perform a common function.
• Organ system: Different organs that work together to perform a common function.
• The cell:
• All multicellular organisms are made up of millions of cells.
• The organization of life:

  atoms - molecules - cells - tissue - organ - organ system - organism
• Microscopic: cannot be seen with the naked eye.
• The cell wall only occurs in plant cells. It is made of cellulose and supports the cell.
• The cell wall provides shape, strength and protection to the cell.
• The cell wall is non-living, rigid and strong.
• The cell membrane occurs in both plants and animal cells.
• The cell membrane is living, thin and elastic.
• The cell membrane surrounds the cytoplasm and it is situated just inside the cell wall
• The cell membrane controls what goes in and out of the cell, it is selectively permeable.
• All organelles float in the cytoplasm.
• Cytoplasm is a jelly-like medium
• The cytoplasm makes up majority of the cell content
• The vacuole is a fluid filled sac that stores cell sap and helps maintain the cell's shape
• Large permanent vacuoles are found in plant cells
• Small, temporary vacuoles are found in animal cells
• The vacuole is a large space in the cytoplasm that is surrounded by a tonoplast(the vacoule's membrane) and the space is filled with dissolved water, mineral salts, wastes and starch(called cell sap).
• Plant cells have rigid cell walls while animal cells do not
• Turgor pressure: the pressure that is exerted by the vacuole on the cell wall to keep the cell rigid/turgid.
• What is the function of the vacuole?


  Storage space in the cell for water and dissolved substances.
• The vacuole maintains turgor pressure in association with the cell wall(helps to maintain the cells shape).
• The chloroplast is only found in the plant cell.
• Chlorophyll: green pigment in chloroplasts that traps radiant energy.
• Chloroplasts perform photosynthesis: 6CO2 + 6H2O → C6H12O6 + 6O2
• The glucose is stored as starch in the vacuoles of plants cells
• The nucleus is filled with nucleoplasm
• The nucleus is surrounded by a nuclear membrane
• Contains the DNA that carries all your hereditary information
• The nucleus is packaged as chromosomes
• Function of the nucleus: Controls hereditary characteristics and controls all the functions of the cell.
• The mitochondrion is a rod-shaped organelle that occurs in both plant and animal cells.
• The mitochondria has a folded inner membrane and a smooth outer membrane.
• The mitochondria is there to perform respiration: O2 + Glucose → ATP + H2O + CO2
• The mitochondria provides the cell with energy in the form of ATP
• What is ATP: Adenosine triphosphate, a molecule that stores energy in the form of chemical bonds.