Biology Notes PDF

# Biology Notes ## Chapter 1: Introduction to Biology - **Variable**: Any parameter in the experiment that can be changed. - **Independent variable**: Variable you can manipulate. - **Dependent variable**: Variable affected by the independent variable. - **Hypothesis**: A testable prediction for...

# Biology Notes ## Chapter 1: Introduction to Biology - **Variable**: Any parameter in the experiment that can be changed. - **Independent variable**: Variable you can manipulate. - **Dependent variable**: Variable affected by the independent variable. - **Hypothesis**: A testable prediction for your experiment. - **Control**: The group you monitor to assess its results without affecting the independent variable. - **Homeostasis**: A state of balance among all the body systems required for the body to survive. - Examples: Body temperature and pH levels. ## Chapter 2: Biochemistry - **4 Elements found in all living things**: Carbon, hydrogen, oxygen, nitrogen. - **Most common compound found in living things**: Water - **Saltwater mixture**: Solute: Salt; Solvent: Water. - **pH Scale**: - Substances below 7 are **acidic**. - Substances at 7 are **neutral**. - Substances above 7 are **basic**. - **pH of 4**: has 1000 times *less* H⁺ ions than a pH of 12. - **pH of 7**: has *more* H⁺ ions than a pH of 10. - **Macromolecules**: | Macromolecule | Monomer | Polymer | Function(s) | |---|---|---|---| | Carbohydrates | Monosaccharide | Polysaccharide | Main energy source | | Lipids | 3 Fatty acids | Lipid | Store energy | | Nucleic Acids | Nucleotide | Nucleic acid | Store genetic info to make proteins | | Proteins | Amino acid | Dipeptide | Control rates of reactions, regulate cell processes, form bones & muscles, and transport materials | - **Function of DNA**: Stores genetic information. - **Formula for Glucose**: C₆H₁₂O₆ ## Chapter 3: Ecology - **Producer**: An organism that makes its own food - algae. - **Consumer**: An organism that eats or consumes to get energy - omnivores. - **Decomposer**: An organism that breaks down dead or decaying material - worms. - **Community**: A group of species living in a shared area; varying species interacting with each other and the surrounding environment. - **Autotroph**: A self-feeding organism - plants. - **Heterotroph**: An other-feeding organism - animals. - **Food Chain**: A linear sequence of energy transfer. - **Food Web**: A complex network of interconnected food chains. - About 10% of energy is passed from one tropic level to another. - **Biotic**: Living factor of the environment. - **Abiotic**: Non-living factor of the environment. ## Chapter 4: Photosynthesis - **Mutualism**: Both organisms benefit - Bees + flowers - **Parasitism**: One organism benefits while the other is harmed - Dog + tick - **Commensalism**: One organism benefits, the other is neutral - Whale + Barnacle. - **Population**: Same species, able to interbreed and produce viable offspring. - **Carrying capacity**: The largest number of individuals of a particular species that a particular environment can support. - **Limiting Factor**: A factor that causes population growth to decrease. - **Niche**: Strategies and adaptations a species uses in its environment. - **Why can 2 species not have the same niche?**: Too much competition for identical resources, one organism will outcompete the other. - **Density-dependent factors**: Factors affected by the population density - predation. - **Density-independent factors**: Not dependent on population density - abiotic factors like weather. - **Function of ATP**: Provides the energy needed for many essential processes in living organisms and cells. - **How is energy released from a molecule?**: ATP molecule spins off one of its three phosphates, becoming ADP + inorganic phosphate. - **Parts of ATP**: 1. Adenosine, 2. Ribose, 3 Phosphate. - **Photosynthesis Equation**: CO₂ + H₂O + sunlight --> C₆H₁₂O₆ + O₂ - **Organelle of plant cell where photosynthesis occurs**: Chloroplast. ## Chapter 5: Cellular Respiration - **Electron source for photosynthesis**: H₂O (water). - **Function of Stomata**: Allows CO₂, H₂O, and O₂ in and out of the cell. - **Cellular Respiration Equation**: C₆H₁₂O₆ + O₂ --> CO₂ + H₂O + ATP + energy - **Aerobic Respiration**: Requires oxygen; produces more energy. - **Anaerobic Respiration**: Does not require oxygen; produces less energy. - **Stages of Aerobic Respiration**: | Stage | Where it occurs? | Number of ATP made | |---|---|---| | Glycolysis | Cytoplasm | 2 | | Krebs Cycle | Mitochondrial matrix | 2 | | ETC | Inner mitochondrial membrane | 34 | - **Most efficient type of respiration**: Aerobic. - **Carbon source in CO₂**: Glucose. - **Stages of anaerobic respiration**: Glycolysis + Fermentation. - **Types of fermentation**: 1. **Alcoholic**: Yeast + Bacteria. Used to make beer. 2. **Lactic Acid**: Animal muscle cells. Used to make sore muscles. - **Relationship between photosynthesis and cellular respiration**: They are inverse reactions. - **Purpose of cellular respiration**: To generate ATP. - **Energy not used by an organism**: Released as heat. - **Electron carrier in cellular respiration**: NAD + FAD. - Produced during the glycolysis stage of cellular respiration. - **3-carbon molecules made at the end of glycolysis**: Pyruvate. - These molecules start the Krebs cycle if oxygen is present. - **Final electron acceptor in cellular respiration**: Oxygen (O₂).