Biology is __________________________. Examines the structure, function, growth, origin, evolution, and distribution of living things.
Seven characteristics of living things: 1) Composed of Cells 2) Levels of organization 3) Use of energy for growth and maintanance 4) Respond to their environment 5) Living things grow 6) Reproduce 7) Adapt to their environment
Why do we start here? LEVELS OF BIOLOGICAL ORGANIZATION: Atoms Molecules (organic and inorganic) ________________ _________ ___________ ____________________ organism ___________________ community biome biosphere
What are cellular Functions? Functions that cells carry out How do cells function Dependent on organic and inorganic molecules (Eg. DNA, Carbohydrates, salt, etc.) BIOCHEMISTRY: the study of biological chemical reactions and the molecules and processes involved in them.
Example of an essential chemical reaction that cells carry out: CELLULAR RESPIRATION The overall reaction can be summarized as: 6O2+ C6H12O6 6CO2+ 6H20 + ENERGY Why is this reaction important? because it provides energy for the cells to carry out their functions
Water: The Primary Molecule of Life the most abundant molecule in any cell. Why is it so important? Carrier for dissolved molecules into and out of the cell Raw material (reactant) in many cell reactions Acts as a lubricant between cells, tissues, and organs Regulates temperature
What allows it to perform these functions? Its Properties Remains liquid over wide temperature ranges Dissolves most substances important in living processes Universal Solvent (O2, CO2, glucose, amino acids, NaCl, etc.) Changes temperature gradually when heated or cooled High Specific Heat Capacity Only pure substance to expand when it is solid floats when it freezes
Water is a POLAR molecule Slightly negative charge on ______ end Slightly positive charge on the ______ end. Why is this important? ________________________________________ _______________________________________
Hydrophillic forms hydrogen bonds with water.
SACRAMENTO, California--A woman who competed in a radio station's contest to see how much water she could drink without going to the bathroom, died of water intoxication. Jennifer Strange, 28, had taken part in the "Hold Your Wee for a Wii" game, which promised the winner a Nintendo Wii. Afterwards, she reportedly said her head was hurting and went home, where she was later found dead. Initial tests showed her death was due to water intoxication. We are regularly advised to drink more water: it clears skin, reduces tiredness and aids concentration. But the death of this woman in the US shows you can have too much of a good thing.
Why is too much water dangerous? Drinking too much water can eventually cause your brain to swell, stopping it from regulating vital functions such as breathing, and causing death. So what happens? Water enters the body when we drink and is removed primarily in the urine and sweat. The amount of water in the body is regulated to control the levels of certain compounds, such as salt, in the blood. If you drink too much water, eventually, the kidneys will not be able to work fast enough to remove sufficient amounts from the body, so the blood becomes more dilute with low salt concentrations. The water then moves from the dilute blood to the cells and organs where there is less water. Too much water in cells can causes them to swell. This swelling is a problem in the brain. When the brain swells, it is inside a bony box. So, it has nowhere to go. The pressure increases in the skull and a headache results. As the brain is squeezed, it compresses vital regions that regulate functions such as breathing. These functions become impaired, breathing stops, and, eventually, it leads to death.
Read page 624, “The Cell Theory” Answer the following questions in your notebook. 1) What are the four points of the cell theory? 2) What three developments in science made it possible to study cells? 3) Where did the biological term “cell” come from?
Read 1.1 and make notes. Do questions 1-6, 8 on page 20