Transcript notes 2.1
HOW CELLS FUNCTION ALL CELLS NEED ENERGY AND MATERIALS FOR LIFE PROCESSES CHEMICAL REACTIONS TAKE PLACE INSIDE CELLS • ALL CELLS ARE MADE OF THE SAME ELEMENTS – All matter in the universe can be broken down into elements (about 100 different ones found on Earth) – 25 are needed for life; 6 make up 99% of human body – Chemical Reactions make/brake bonds between atoms to make different molecules – ENERGY is needed to make bonds & is released when bonds are broken • LARGE MOLECULES SUPPORT CELL FUNCTION (carbohydrates, lipids, proteins & nucleic acids) • ABOUT 2/3 OF EVERY CELL IS WATER CARBOHYDRATES • Provides cell with ENERGY • Simple carbs are SUGARS which are broken down in cell to release energy. • Complex carbs are STARCH (sugars linked & stored together) and CELLULOSE (nondigestible in cell walls). LIPIDS • Are FATS, OILS, & WAXES, found in living things. • Can store lots of ENERGY and used for structural support. • Made of glycerol & fatty acids; doesn’t mix with water. PROTEINS -Made of amino acids -Get amino acids from eggs, meat, beans & dairy -Used to build & repair; make enzymes for chemical reactions, help blood fight infections & carry oxygen NUCLEIC ACIDS • Are molecules that hold instructions for the maintenance, growth, & reproduction of a cell. • 2 Types: DNA (holds information on how to make the body’s proteins) & RNA (copies data from DNA in nucleus and takes to cytoplasm so amino acids can link into protein) • Made of nucleotides ABOUT 2/3 OF EVERY CELL IS WATER • All CHEMICAL REACTIONS inside a cell takes place in WATER. • Water is made of H2O; 2 hydrogen atoms and one oxygen atom • Water is found both inside & outside of a cell; the cell membrane’s lipid layer separates the 2 environments of water (inside & outside of the cell) . The water hating tails in the lipids repel the water while the head clings to water.